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avcodec.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc Encoding/Decoding Library
47  * @{
48  *
49  * @defgroup lavc_decoding Decoding
50  * @{
51  * @}
52  *
53  * @defgroup lavc_encoding Encoding
54  * @{
55  * @}
56  *
57  * @defgroup lavc_codec Codecs
58  * @{
59  * @defgroup lavc_codec_native Native Codecs
60  * @{
61  * @}
62  * @defgroup lavc_codec_wrappers External library wrappers
63  * @{
64  * @}
65  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
66  * @{
67  * @}
68  * @}
69  * @defgroup lavc_internal Internal
70  * @{
71  * @}
72  * @}
73  *
74  */
75 
76 /**
77  * @defgroup lavc_core Core functions/structures.
78  * @ingroup libavc
79  *
80  * Basic definitions, functions for querying libavcodec capabilities,
81  * allocating core structures, etc.
82  * @{
83  */
84 
85 
86 /**
87  * Identify the syntax and semantics of the bitstream.
88  * The principle is roughly:
89  * Two decoders with the same ID can decode the same streams.
90  * Two encoders with the same ID can encode compatible streams.
91  * There may be slight deviations from the principle due to implementation
92  * details.
93  *
94  * If you add a codec ID to this list, add it so that
95  * 1. no value of a existing codec ID changes (that would break ABI),
96  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
97  * This ensures that 2 forks can independently add AVCodecIDs without producing conflicts.
98  *
99  * After adding new codec IDs, do not forget to add an entry to the codec
100  * descriptor list and bump libavcodec minor version.
101  */
102 enum AVCodecID {
104 
105  /* video codecs */
107  AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
279 
280  AV_CODEC_ID_BRENDER_PIX= MKBETAG('B','P','I','X'),
281  AV_CODEC_ID_Y41P = MKBETAG('Y','4','1','P'),
282  AV_CODEC_ID_ESCAPE130 = MKBETAG('E','1','3','0'),
283  AV_CODEC_ID_EXR = MKBETAG('0','E','X','R'),
284  AV_CODEC_ID_AVRP = MKBETAG('A','V','R','P'),
285 
286  AV_CODEC_ID_012V = MKBETAG('0','1','2','V'),
287  AV_CODEC_ID_G2M = MKBETAG( 0 ,'G','2','M'),
288  AV_CODEC_ID_AVUI = MKBETAG('A','V','U','I'),
289  AV_CODEC_ID_AYUV = MKBETAG('A','Y','U','V'),
290  AV_CODEC_ID_TARGA_Y216 = MKBETAG('T','2','1','6'),
291  AV_CODEC_ID_V308 = MKBETAG('V','3','0','8'),
292  AV_CODEC_ID_V408 = MKBETAG('V','4','0','8'),
293  AV_CODEC_ID_YUV4 = MKBETAG('Y','U','V','4'),
294  AV_CODEC_ID_SANM = MKBETAG('S','A','N','M'),
295  AV_CODEC_ID_PAF_VIDEO = MKBETAG('P','A','F','V'),
296  AV_CODEC_ID_AVRN = MKBETAG('A','V','R','n'),
297  AV_CODEC_ID_CPIA = MKBETAG('C','P','I','A'),
298  AV_CODEC_ID_XFACE = MKBETAG('X','F','A','C'),
299  AV_CODEC_ID_SGIRLE = MKBETAG('S','G','I','R'),
300  AV_CODEC_ID_MVC1 = MKBETAG('M','V','C','1'),
301  AV_CODEC_ID_MVC2 = MKBETAG('M','V','C','2'),
302  AV_CODEC_ID_SNOW = MKBETAG('S','N','O','W'),
303  AV_CODEC_ID_WEBP = MKBETAG('W','E','B','P'),
304  AV_CODEC_ID_SMVJPEG = MKBETAG('S','M','V','J'),
305  AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
306 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
307 
308  /* various PCM "codecs" */
309  AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
343 
344  /* various ADPCM codecs */
375  AV_CODEC_ID_VIMA = MKBETAG('V','I','M','A'),
376  AV_CODEC_ID_ADPCM_AFC = MKBETAG('A','F','C',' '),
377  AV_CODEC_ID_ADPCM_IMA_OKI = MKBETAG('O','K','I',' '),
378  AV_CODEC_ID_ADPCM_DTK = MKBETAG('D','T','K',' '),
379  AV_CODEC_ID_ADPCM_IMA_RAD = MKBETAG('R','A','D',' '),
380  AV_CODEC_ID_ADPCM_G726LE = MKBETAG('6','2','7','G'),
381 
382  /* AMR */
385 
386  /* RealAudio codecs*/
389 
390  /* various DPCM codecs */
395 
396  /* audio codecs */
397  AV_CODEC_ID_MP2 = 0x15000,
398  AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
415  AV_CODEC_ID_GSM, ///< as in Berlin toast format
427  AV_CODEC_ID_GSM_MS, /* as found in WAV */
429 #if FF_API_VOXWARE
430  AV_CODEC_ID_VOXWARE,
431 #endif
464  AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
465  AV_CODEC_ID_SONIC = MKBETAG('S','O','N','C'),
466  AV_CODEC_ID_SONIC_LS = MKBETAG('S','O','N','L'),
467  AV_CODEC_ID_PAF_AUDIO = MKBETAG('P','A','F','A'),
468  AV_CODEC_ID_OPUS = MKBETAG('O','P','U','S'),
469  AV_CODEC_ID_TAK = MKBETAG('t','B','a','K'),
470  AV_CODEC_ID_EVRC = MKBETAG('s','e','v','c'),
471  AV_CODEC_ID_SMV = MKBETAG('s','s','m','v'),
472 
473  /* subtitle codecs */
474  AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs.
477  AV_CODEC_ID_TEXT, ///< raw UTF-8 text
484  AV_CODEC_ID_MICRODVD = MKBETAG('m','D','V','D'),
485  AV_CODEC_ID_EIA_608 = MKBETAG('c','6','0','8'),
486  AV_CODEC_ID_JACOSUB = MKBETAG('J','S','U','B'),
487  AV_CODEC_ID_SAMI = MKBETAG('S','A','M','I'),
488  AV_CODEC_ID_REALTEXT = MKBETAG('R','T','X','T'),
489  AV_CODEC_ID_SUBVIEWER1 = MKBETAG('S','b','V','1'),
490  AV_CODEC_ID_SUBVIEWER = MKBETAG('S','u','b','V'),
491  AV_CODEC_ID_SUBRIP = MKBETAG('S','R','i','p'),
492  AV_CODEC_ID_WEBVTT = MKBETAG('W','V','T','T'),
493  AV_CODEC_ID_MPL2 = MKBETAG('M','P','L','2'),
494  AV_CODEC_ID_VPLAYER = MKBETAG('V','P','l','r'),
495  AV_CODEC_ID_PJS = MKBETAG('P','h','J','S'),
496  AV_CODEC_ID_ASS = MKBETAG('A','S','S',' '), ///< ASS as defined in Matroska
497 
498  /* other specific kind of codecs (generally used for attachments) */
499  AV_CODEC_ID_FIRST_UNKNOWN = 0x18000, ///< A dummy ID pointing at the start of various fake codecs.
500  AV_CODEC_ID_TTF = 0x18000,
501  AV_CODEC_ID_BINTEXT = MKBETAG('B','T','X','T'),
502  AV_CODEC_ID_XBIN = MKBETAG('X','B','I','N'),
503  AV_CODEC_ID_IDF = MKBETAG( 0 ,'I','D','F'),
504  AV_CODEC_ID_OTF = MKBETAG( 0 ,'O','T','F'),
505  AV_CODEC_ID_SMPTE_KLV = MKBETAG('K','L','V','A'),
506  AV_CODEC_ID_DVD_NAV = MKBETAG('D','N','A','V'),
507 
508 
509  AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
510 
511  AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
512  * stream (only used by libavformat) */
513  AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
514  * stream (only used by libavformat) */
515  AV_CODEC_ID_FFMETADATA = 0x21000, ///< Dummy codec for streams containing only metadata information.
516 
517 #if FF_API_CODEC_ID
518 #include "old_codec_ids.h"
519 #endif
520 };
521 
522 /**
523  * This struct describes the properties of a single codec described by an
524  * AVCodecID.
525  * @see avcodec_get_descriptor()
526  */
527 typedef struct AVCodecDescriptor {
528  enum AVCodecID id;
530  /**
531  * Name of the codec described by this descriptor. It is non-empty and
532  * unique for each codec descriptor. It should contain alphanumeric
533  * characters and '_' only.
534  */
535  const char *name;
536  /**
537  * A more descriptive name for this codec. May be NULL.
538  */
539  const char *long_name;
540  /**
541  * Codec properties, a combination of AV_CODEC_PROP_* flags.
542  */
543  int props;
545 
546 /**
547  * Codec uses only intra compression.
548  * Video codecs only.
549  */
550 #define AV_CODEC_PROP_INTRA_ONLY (1 << 0)
551 /**
552  * Codec supports lossy compression. Audio and video codecs only.
553  * @note a codec may support both lossy and lossless
554  * compression modes
555  */
556 #define AV_CODEC_PROP_LOSSY (1 << 1)
557 /**
558  * Codec supports lossless compression. Audio and video codecs only.
559  */
560 #define AV_CODEC_PROP_LOSSLESS (1 << 2)
561 /**
562  * Subtitle codec is bitmap based
563  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
564  */
565 #define AV_CODEC_PROP_BITMAP_SUB (1 << 16)
566 /**
567  * Subtitle codec is text based.
568  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
569  */
570 #define AV_CODEC_PROP_TEXT_SUB (1 << 17)
571 
572 /**
573  * @ingroup lavc_decoding
574  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
575  * This is mainly needed because some optimized bitstream readers read
576  * 32 or 64 bit at once and could read over the end.<br>
577  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
578  * MPEG bitstreams could cause overread and segfault.
579  */
580 #define FF_INPUT_BUFFER_PADDING_SIZE 16
581 
582 /**
583  * @ingroup lavc_encoding
584  * minimum encoding buffer size
585  * Used to avoid some checks during header writing.
586  */
587 #define FF_MIN_BUFFER_SIZE 16384
588 
589 
590 /**
591  * @ingroup lavc_encoding
592  * motion estimation type.
593  */
595  ME_ZERO = 1, ///< no search, that is use 0,0 vector whenever one is needed
599  ME_EPZS, ///< enhanced predictive zonal search
600  ME_X1, ///< reserved for experiments
601  ME_HEX, ///< hexagon based search
602  ME_UMH, ///< uneven multi-hexagon search
603  ME_TESA, ///< transformed exhaustive search algorithm
604  ME_ITER=50, ///< iterative search
605 };
606 
607 /**
608  * @ingroup lavc_decoding
609  */
611  /* We leave some space between them for extensions (drop some
612  * keyframes for intra-only or drop just some bidir frames). */
613  AVDISCARD_NONE =-16, ///< discard nothing
614  AVDISCARD_DEFAULT = 0, ///< discard useless packets like 0 size packets in avi
615  AVDISCARD_NONREF = 8, ///< discard all non reference
616  AVDISCARD_BIDIR = 16, ///< discard all bidirectional frames
617  AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
618  AVDISCARD_ALL = 48, ///< discard all
619 };
620 
622  AVCOL_PRI_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
625  AVCOL_PRI_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
626  AVCOL_PRI_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
627  AVCOL_PRI_SMPTE240M = 7, ///< functionally identical to above
629  AVCOL_PRI_NB , ///< Not part of ABI
630 };
631 
633  AVCOL_TRC_BT709 = 1, ///< also ITU-R BT1361
635  AVCOL_TRC_GAMMA22 = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
636  AVCOL_TRC_GAMMA28 = 5, ///< also ITU-R BT470BG
638  AVCOL_TRC_NB , ///< Not part of ABI
639 };
640 
641 /**
642  * X X 3 4 X X are luma samples,
643  * 1 2 1-6 are possible chroma positions
644  * X X 5 6 X 0 is undefined/unknown position
645  */
648  AVCHROMA_LOC_LEFT = 1, ///< mpeg2/4, h264 default
649  AVCHROMA_LOC_CENTER = 2, ///< mpeg1, jpeg, h263
650  AVCHROMA_LOC_TOPLEFT = 3, ///< DV
654  AVCHROMA_LOC_NB , ///< Not part of ABI
655 };
656 
667  AV_AUDIO_SERVICE_TYPE_NB , ///< Not part of ABI
668 };
669 
670 /**
671  * @ingroup lavc_encoding
672  */
673 typedef struct RcOverride{
676  int qscale; // If this is 0 then quality_factor will be used instead.
678 } RcOverride;
679 
680 #define FF_MAX_B_FRAMES 16
681 
682 /* encoding support
683  These flags can be passed in AVCodecContext.flags before initialization.
684  Note: Not everything is supported yet.
685 */
686 
687 /**
688  * Allow decoders to produce frames with data planes that are not aligned
689  * to CPU requirements (e.g. due to cropping).
690  */
691 #define CODEC_FLAG_UNALIGNED 0x0001
692 #define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
693 #define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
694 #define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
695 #define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
696 #define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
697 /**
698  * The parent program guarantees that the input for B-frames containing
699  * streams is not written to for at least s->max_b_frames+1 frames, if
700  * this is not set the input will be copied.
701  */
702 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
703 #define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
704 #define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
705 #define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
706 #define CODEC_FLAG_EMU_EDGE 0x4000 ///< Don't draw edges.
707 #define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
708 #define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random
709  location instead of only at frame boundaries. */
710 #define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
711 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
712 #define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
713 #define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
714 #define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
715 /* Fx : Flag for h263+ extra options */
716 #define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
717 #define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
718 #define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
719 #define CODEC_FLAG_CLOSED_GOP 0x80000000
720 #define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
721 #define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
722 #define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
723 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format. DEPRECATED!!!!
724 #define CODEC_FLAG2_IGNORE_CROP 0x00010000 ///< Discard cropping information from SPS.
726 #define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
727 #define CODEC_FLAG2_SHOW_ALL 0x00400000 ///< Show all frames before the first keyframe
728 
729 /* Unsupported options :
730  * Syntax Arithmetic coding (SAC)
731  * Reference Picture Selection
732  * Independent Segment Decoding */
733 /* /Fx */
734 /* codec capabilities */
736 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
737 /**
738  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
739  * If not set, it might not use get_buffer() at all or use operations that
740  * assume the buffer was allocated by avcodec_default_get_buffer.
741  */
742 #define CODEC_CAP_DR1 0x0002
743 #define CODEC_CAP_TRUNCATED 0x0008
744 /* Codec can export data for HW decoding (XvMC). */
745 #define CODEC_CAP_HWACCEL 0x0010
746 /**
747  * Encoder or decoder requires flushing with NULL input at the end in order to
748  * give the complete and correct output.
749  *
750  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
751  * with NULL data. The user can still send NULL data to the public encode
752  * or decode function, but libavcodec will not pass it along to the codec
753  * unless this flag is set.
754  *
755  * Decoders:
756  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
757  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
758  * returns frames.
759  *
760  * Encoders:
761  * The encoder needs to be fed with NULL data at the end of encoding until the
762  * encoder no longer returns data.
763  *
764  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
765  * flag also means that the encoder must set the pts and duration for
766  * each output packet. If this flag is not set, the pts and duration will
767  * be determined by libavcodec from the input frame.
768  */
769 #define CODEC_CAP_DELAY 0x0020
770 /**
771  * Codec can be fed a final frame with a smaller size.
772  * This can be used to prevent truncation of the last audio samples.
773  */
774 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040
775 #if FF_API_CAP_VDPAU
776 /**
777  * Codec can export data for HW decoding (VDPAU).
778  */
779 #define CODEC_CAP_HWACCEL_VDPAU 0x0080
780 #endif
781 /**
782  * Codec can output multiple frames per AVPacket
783  * Normally demuxers return one frame at a time, demuxers which do not do
784  * are connected to a parser to split what they return into proper frames.
785  * This flag is reserved to the very rare category of codecs which have a
786  * bitstream that cannot be split into frames without timeconsuming
787  * operations like full decoding. Demuxers carring such bitstreams thus
788  * may return multiple frames in a packet. This has many disadvantages like
789  * prohibiting stream copy in many cases thus it should only be considered
790  * as a last resort.
791  */
792 #define CODEC_CAP_SUBFRAMES 0x0100
793 /**
794  * Codec is experimental and is thus avoided in favor of non experimental
795  * encoders
796  */
797 #define CODEC_CAP_EXPERIMENTAL 0x0200
798 /**
799  * Codec should fill in channel configuration and samplerate instead of container
800  */
801 #define CODEC_CAP_CHANNEL_CONF 0x0400
802 
803 /**
804  * Codec is able to deal with negative linesizes
805  */
806 #define CODEC_CAP_NEG_LINESIZES 0x0800
807 
808 /**
809  * Codec supports frame-level multithreading.
810  */
811 #define CODEC_CAP_FRAME_THREADS 0x1000
812 /**
813  * Codec supports slice-based (or partition-based) multithreading.
814  */
815 #define CODEC_CAP_SLICE_THREADS 0x2000
816 /**
817  * Codec supports changed parameters at any point.
818  */
819 #define CODEC_CAP_PARAM_CHANGE 0x4000
820 /**
821  * Codec supports avctx->thread_count == 0 (auto).
822  */
823 #define CODEC_CAP_AUTO_THREADS 0x8000
824 /**
825  * Audio encoder supports receiving a different number of samples in each call.
826  */
827 #define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
828 /**
829  * Codec is intra only.
830  */
831 #define CODEC_CAP_INTRA_ONLY 0x40000000
832 /**
833  * Codec is lossless.
834  */
835 #define CODEC_CAP_LOSSLESS 0x80000000
836 
837 //The following defines may change, don't expect compatibility if you use them.
838 #define MB_TYPE_INTRA4x4 0x0001
839 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
840 #define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
841 #define MB_TYPE_16x16 0x0008
842 #define MB_TYPE_16x8 0x0010
843 #define MB_TYPE_8x16 0x0020
844 #define MB_TYPE_8x8 0x0040
845 #define MB_TYPE_INTERLACED 0x0080
846 #define MB_TYPE_DIRECT2 0x0100 //FIXME
847 #define MB_TYPE_ACPRED 0x0200
848 #define MB_TYPE_GMC 0x0400
849 #define MB_TYPE_SKIP 0x0800
850 #define MB_TYPE_P0L0 0x1000
851 #define MB_TYPE_P1L0 0x2000
852 #define MB_TYPE_P0L1 0x4000
853 #define MB_TYPE_P1L1 0x8000
854 #define MB_TYPE_L0 (MB_TYPE_P0L0 | MB_TYPE_P1L0)
855 #define MB_TYPE_L1 (MB_TYPE_P0L1 | MB_TYPE_P1L1)
856 #define MB_TYPE_L0L1 (MB_TYPE_L0 | MB_TYPE_L1)
857 #define MB_TYPE_QUANT 0x00010000
858 #define MB_TYPE_CBP 0x00020000
859 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
860 
861 /**
862  * Pan Scan area.
863  * This specifies the area which should be displayed.
864  * Note there may be multiple such areas for one frame.
865  */
866 typedef struct AVPanScan{
867  /**
868  * id
869  * - encoding: Set by user.
870  * - decoding: Set by libavcodec.
871  */
872  int id;
873 
874  /**
875  * width and height in 1/16 pel
876  * - encoding: Set by user.
877  * - decoding: Set by libavcodec.
878  */
879  int width;
880  int height;
881 
882  /**
883  * position of the top left corner in 1/16 pel for up to 3 fields/frames
884  * - encoding: Set by user.
885  * - decoding: Set by libavcodec.
886  */
887  int16_t position[3][2];
888 }AVPanScan;
890 #define FF_QSCALE_TYPE_MPEG1 0
891 #define FF_QSCALE_TYPE_MPEG2 1
892 #define FF_QSCALE_TYPE_H264 2
893 #define FF_QSCALE_TYPE_VP56 3
894 
895 #if FF_API_GET_BUFFER
896 #define FF_BUFFER_TYPE_INTERNAL 1
897 #define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
898 #define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
899 #define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
900 
901 #define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
902 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
903 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
904 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
905 #endif
906 
907 /**
908  * The decoder will keep a reference to the frame and may reuse it later.
909  */
910 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
911 
912 /**
913  * @defgroup lavc_packet AVPacket
914  *
915  * Types and functions for working with AVPacket.
916  * @{
917  */
921 
922  /**
923  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
924  * @code
925  * u32le param_flags
926  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
927  * s32le channel_count
928  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
929  * u64le channel_layout
930  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
931  * s32le sample_rate
932  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
933  * s32le width
934  * s32le height
935  * @endcode
936  */
938 
939  /**
940  * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
941  * structures with info about macroblocks relevant to splitting the
942  * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
943  * That is, it does not necessarily contain info about all macroblocks,
944  * as long as the distance between macroblocks in the info is smaller
945  * than the target payload size.
946  * Each MB info structure is 12 bytes, and is laid out as follows:
947  * @code
948  * u32le bit offset from the start of the packet
949  * u8 current quantizer at the start of the macroblock
950  * u8 GOB number
951  * u16le macroblock address within the GOB
952  * u8 horizontal MV predictor
953  * u8 vertical MV predictor
954  * u8 horizontal MV predictor for block number 3
955  * u8 vertical MV predictor for block number 3
956  * @endcode
957  */
959 
960  /**
961  * Recommmends skipping the specified number of samples
962  * @code
963  * u32le number of samples to skip from start of this packet
964  * u32le number of samples to skip from end of this packet
965  * u8 reason for start skip
966  * u8 reason for end skip (0=padding silence, 1=convergence)
967  * @endcode
968  */
970 
971  /**
972  * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
973  * the packet may contain "dual mono" audio specific to Japanese DTV
974  * and if it is true, recommends only the selected channel to be used.
975  * @code
976  * u8 selected channels (0=mail/left, 1=sub/right, 2=both)
977  * @endcode
978  */
980 
981  /**
982  * A list of zero terminated key/value strings. There is no end marker for
983  * the list, so it is required to rely on the side data size to stop.
984  */
986 
987  /**
988  * Subtitle event position
989  * @code
990  * u32le x1
991  * u32le y1
992  * u32le x2
993  * u32le y2
994  * @endcode
995  */
997 
998  /**
999  * Data found in BlockAdditional element of matroska container. There is
1000  * no end marker for the data, so it is required to rely on the side data
1001  * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1002  * by data.
1003  */
1005 
1006  /**
1007  * The optional first identifier line of a WebVTT cue.
1008  */
1010 
1011  /**
1012  * The optional settings (rendering instructions) that immediately
1013  * follow the timestamp specifier of a WebVTT cue.
1014  */
1016 };
1017 
1018 /**
1019  * This structure stores compressed data. It is typically exported by demuxers
1020  * and then passed as input to decoders, or received as output from encoders and
1021  * then passed to muxers.
1022  *
1023  * For video, it should typically contain one compressed frame. For audio it may
1024  * contain several compressed frames.
1025  *
1026  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1027  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1028  * without libavcodec and libavformat major bump.
1029  *
1030  * The semantics of data ownership depends on the buf or destruct (deprecated)
1031  * fields. If either is set, the packet data is dynamically allocated and is
1032  * valid indefinitely until av_free_packet() is called (which in turn calls
1033  * av_buffer_unref()/the destruct callback to free the data). If neither is set,
1034  * the packet data is typically backed by some static buffer somewhere and is
1035  * only valid for a limited time (e.g. until the next read call when demuxing).
1036  *
1037  * The side data is always allocated with av_malloc() and is freed in
1038  * av_free_packet().
1039  */
1040 typedef struct AVPacket {
1041  /**
1042  * A reference to the reference-counted buffer where the packet data is
1043  * stored.
1044  * May be NULL, then the packet data is not reference-counted.
1045  */
1046  AVBufferRef *buf;
1047  /**
1048  * Presentation timestamp in AVStream->time_base units; the time at which
1049  * the decompressed packet will be presented to the user.
1050  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1051  * pts MUST be larger or equal to dts as presentation cannot happen before
1052  * decompression, unless one wants to view hex dumps. Some formats misuse
1053  * the terms dts and pts/cts to mean something different. Such timestamps
1054  * must be converted to true pts/dts before they are stored in AVPacket.
1055  */
1056  int64_t pts;
1057  /**
1058  * Decompression timestamp in AVStream->time_base units; the time at which
1059  * the packet is decompressed.
1060  * Can be AV_NOPTS_VALUE if it is not stored in the file.
1061  */
1062  int64_t dts;
1064  int size;
1065  int stream_index;
1066  /**
1067  * A combination of AV_PKT_FLAG values
1068  */
1069  int flags;
1070  /**
1071  * Additional packet data that can be provided by the container.
1072  * Packet can contain several types of side information.
1073  */
1074  struct {
1075  uint8_t *data;
1076  int size;
1079  int side_data_elems;
1080 
1081  /**
1082  * Duration of this packet in AVStream->time_base units, 0 if unknown.
1083  * Equals next_pts - this_pts in presentation order.
1084  */
1085  int duration;
1086 #if FF_API_DESTRUCT_PACKET
1088  void (*destruct)(struct AVPacket *);
1090  void *priv;
1091 #endif
1092  int64_t pos; ///< byte position in stream, -1 if unknown
1093 
1094  /**
1095  * Time difference in AVStream->time_base units from the pts of this
1096  * packet to the point at which the output from the decoder has converged
1097  * independent from the availability of previous frames. That is, the
1098  * frames are virtually identical no matter if decoding started from
1099  * the very first frame or from this keyframe.
1100  * Is AV_NOPTS_VALUE if unknown.
1101  * This field is not the display duration of the current packet.
1102  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
1103  * set.
1104  *
1105  * The purpose of this field is to allow seeking in streams that have no
1106  * keyframes in the conventional sense. It corresponds to the
1107  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
1108  * essential for some types of subtitle streams to ensure that all
1109  * subtitles are correctly displayed after seeking.
1110  */
1111  int64_t convergence_duration;
1113 #define AV_PKT_FLAG_KEY 0x0001 ///< The packet contains a keyframe
1114 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1121 };
1122 /**
1123  * @}
1124  */
1125 
1126 struct AVCodecInternal;
1131  AV_FIELD_TT, //< Top coded_first, top displayed first
1132  AV_FIELD_BB, //< Bottom coded first, bottom displayed first
1133  AV_FIELD_TB, //< Top coded first, bottom displayed first
1134  AV_FIELD_BT, //< Bottom coded first, top displayed first
1135 };
1136 
1137 /**
1138  * main external API structure.
1139  * New fields can be added to the end with minor version bumps.
1140  * Removal, reordering and changes to existing fields require a major
1141  * version bump.
1142  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1143  * applications.
1144  * sizeof(AVCodecContext) must not be used outside libav*.
1145  */
1146 typedef struct AVCodecContext {
1147  /**
1148  * information on struct for av_log
1149  * - set by avcodec_alloc_context3
1150  */
1152  int log_level_offset;
1154  enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1155  const struct AVCodec *codec;
1156  char codec_name[32];
1157  enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
1158 
1159  /**
1160  * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1161  * This is used to work around some encoder bugs.
1162  * A demuxer should set this to what is stored in the field used to identify the codec.
1163  * If there are multiple such fields in a container then the demuxer should choose the one
1164  * which maximizes the information about the used codec.
1165  * If the codec tag field in a container is larger than 32 bits then the demuxer should
1166  * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1167  * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1168  * first.
1169  * - encoding: Set by user, if not then the default based on codec_id will be used.
1170  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1171  */
1172  unsigned int codec_tag;
1173 
1174  /**
1175  * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1176  * This is used to work around some encoder bugs.
1177  * - encoding: unused
1178  * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1179  */
1180  unsigned int stream_codec_tag;
1182  void *priv_data;
1183 
1184  /**
1185  * Private context used for internal data.
1186  *
1187  * Unlike priv_data, this is not codec-specific. It is used in general
1188  * libavcodec functions.
1189  */
1190  struct AVCodecInternal *internal;
1191 
1192  /**
1193  * Private data of the user, can be used to carry app specific stuff.
1194  * - encoding: Set by user.
1195  * - decoding: Set by user.
1196  */
1197  void *opaque;
1198 
1199  /**
1200  * the average bitrate
1201  * - encoding: Set by user; unused for constant quantizer encoding.
1202  * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
1203  */
1204  int bit_rate;
1205 
1206  /**
1207  * number of bits the bitstream is allowed to diverge from the reference.
1208  * the reference can be CBR (for CBR pass1) or VBR (for pass2)
1209  * - encoding: Set by user; unused for constant quantizer encoding.
1210  * - decoding: unused
1211  */
1212  int bit_rate_tolerance;
1213 
1214  /**
1215  * Global quality for codecs which cannot change it per frame.
1216  * This should be proportional to MPEG-1/2/4 qscale.
1217  * - encoding: Set by user.
1218  * - decoding: unused
1219  */
1220  int global_quality;
1221 
1222  /**
1223  * - encoding: Set by user.
1224  * - decoding: unused
1225  */
1227 #define FF_COMPRESSION_DEFAULT -1
1228 
1229  /**
1230  * CODEC_FLAG_*.
1231  * - encoding: Set by user.
1232  * - decoding: Set by user.
1233  */
1234  int flags;
1235 
1236  /**
1237  * CODEC_FLAG2_*
1238  * - encoding: Set by user.
1239  * - decoding: Set by user.
1240  */
1241  int flags2;
1242 
1243  /**
1244  * some codecs need / can use extradata like Huffman tables.
1245  * mjpeg: Huffman tables
1246  * rv10: additional flags
1247  * mpeg4: global headers (they can be in the bitstream or here)
1248  * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
1249  * than extradata_size to avoid problems if it is read with the bitstream reader.
1250  * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1251  * - encoding: Set/allocated/freed by libavcodec.
1252  * - decoding: Set/allocated/freed by user.
1253  */
1255  int extradata_size;
1256 
1257  /**
1258  * This is the fundamental unit of time (in seconds) in terms
1259  * of which frame timestamps are represented. For fixed-fps content,
1260  * timebase should be 1/framerate and timestamp increments should be
1261  * identically 1.
1262  * - encoding: MUST be set by user.
1263  * - decoding: Set by libavcodec.
1264  */
1266 
1267  /**
1268  * For some codecs, the time base is closer to the field rate than the frame rate.
1269  * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1270  * if no telecine is used ...
1271  *
1272  * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1273  */
1274  int ticks_per_frame;
1275 
1276  /**
1277  * Codec delay.
1278  *
1279  * Encoding: Number of frames delay there will be from the encoder input to
1280  * the decoder output. (we assume the decoder matches the spec)
1281  * Decoding: Number of frames delay in addition to what a standard decoder
1282  * as specified in the spec would produce.
1283  *
1284  * Video:
1285  * Number of frames the decoded output will be delayed relative to the
1286  * encoded input.
1287  *
1288  * Audio:
1289  * For encoding, this is the number of "priming" samples added to the
1290  * beginning of the stream. The decoded output will be delayed by this
1291  * many samples relative to the input to the encoder. Note that this
1292  * field is purely informational and does not directly affect the pts
1293  * output by the encoder, which should always be based on the actual
1294  * presentation time, including any delay.
1295  * For decoding, this is the number of samples the decoder needs to
1296  * output before the decoder's output is valid. When seeking, you should
1297  * start decoding this many samples prior to your desired seek point.
1298  *
1299  * - encoding: Set by libavcodec.
1300  * - decoding: Set by libavcodec.
1301  */
1302  int delay;
1303 
1304 
1305  /* video only */
1306  /**
1307  * picture width / height.
1308  * - encoding: MUST be set by user.
1309  * - decoding: May be set by the user before opening the decoder if known e.g.
1310  * from the container. Some decoders will require the dimensions
1311  * to be set by the caller. During decoding, the decoder may
1312  * overwrite those values as required.
1313  */
1314  int width, height;
1315 
1316  /**
1317  * Bitstream width / height, may be different from width/height e.g. when
1318  * the decoded frame is cropped before being output or lowres is enabled.
1319  * - encoding: unused
1320  * - decoding: May be set by the user before opening the decoder if known
1321  * e.g. from the container. During decoding, the decoder may
1322  * overwrite those values as required.
1323  */
1326 #define FF_ASPECT_EXTENDED 15
1327 
1328  /**
1329  * the number of pictures in a group of pictures, or 0 for intra_only
1330  * - encoding: Set by user.
1331  * - decoding: unused
1332  */
1333  int gop_size;
1334 
1335  /**
1336  * Pixel format, see AV_PIX_FMT_xxx.
1337  * May be set by the demuxer if known from headers.
1338  * May be overridden by the decoder if it knows better.
1339  * - encoding: Set by user.
1340  * - decoding: Set by user if known, overridden by libavcodec if known
1341  */
1342  enum AVPixelFormat pix_fmt;
1343 
1344  /**
1345  * Motion estimation algorithm used for video coding.
1346  * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
1347  * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
1348  * - encoding: MUST be set by user.
1349  * - decoding: unused
1350  */
1351  int me_method;
1352 
1353  /**
1354  * If non NULL, 'draw_horiz_band' is called by the libavcodec
1355  * decoder to draw a horizontal band. It improves cache usage. Not
1356  * all codecs can do that. You must check the codec capabilities
1357  * beforehand.
1358  * When multithreading is used, it may be called from multiple threads
1359  * at the same time; threads might draw different parts of the same AVFrame,
1360  * or multiple AVFrames, and there is no guarantee that slices will be drawn
1361  * in order.
1362  * The function is also used by hardware acceleration APIs.
1363  * It is called at least once during frame decoding to pass
1364  * the data needed for hardware render.
1365  * In that mode instead of pixel data, AVFrame points to
1366  * a structure specific to the acceleration API. The application
1367  * reads the structure and can change some fields to indicate progress
1368  * or mark state.
1369  * - encoding: unused
1370  * - decoding: Set by user.
1371  * @param height the height of the slice
1372  * @param y the y position of the slice
1373  * @param type 1->top field, 2->bottom field, 3->frame
1374  * @param offset offset into the AVFrame.data from which the slice should be read
1375  */
1376  void (*draw_horiz_band)(struct AVCodecContext *s,
1377  const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1378  int y, int type, int height);
1379 
1380  /**
1381  * callback to negotiate the pixelFormat
1382  * @param fmt is the list of formats which are supported by the codec,
1383  * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1384  * The first is always the native one.
1385  * @return the chosen format
1386  * - encoding: unused
1387  * - decoding: Set by user, if not set the native format will be chosen.
1388  */
1389  enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1390 
1391  /**
1392  * maximum number of B-frames between non-B-frames
1393  * Note: The output will be delayed by max_b_frames+1 relative to the input.
1394  * - encoding: Set by user.
1395  * - decoding: unused
1396  */
1397  int max_b_frames;
1398 
1399  /**
1400  * qscale factor between IP and B-frames
1401  * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1402  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1403  * - encoding: Set by user.
1404  * - decoding: unused
1405  */
1406  float b_quant_factor;
1407 
1408  /** obsolete FIXME remove */
1410 #define FF_RC_STRATEGY_XVID 1
1412  int b_frame_strategy;
1413 
1414  /**
1415  * qscale offset between IP and B-frames
1416  * - encoding: Set by user.
1417  * - decoding: unused
1418  */
1419  float b_quant_offset;
1420 
1421  /**
1422  * Size of the frame reordering buffer in the decoder.
1423  * For MPEG-2 it is 1 IPB or 0 low delay IP.
1424  * - encoding: Set by libavcodec.
1425  * - decoding: Set by libavcodec.
1426  */
1427  int has_b_frames;
1428 
1429  /**
1430  * 0-> h263 quant 1-> mpeg quant
1431  * - encoding: Set by user.
1432  * - decoding: unused
1433  */
1434  int mpeg_quant;
1435 
1436  /**
1437  * qscale factor between P and I-frames
1438  * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1439  * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1440  * - encoding: Set by user.
1441  * - decoding: unused
1442  */
1443  float i_quant_factor;
1444 
1445  /**
1446  * qscale offset between P and I-frames
1447  * - encoding: Set by user.
1448  * - decoding: unused
1449  */
1450  float i_quant_offset;
1451 
1452  /**
1453  * luminance masking (0-> disabled)
1454  * - encoding: Set by user.
1455  * - decoding: unused
1456  */
1457  float lumi_masking;
1458 
1459  /**
1460  * temporary complexity masking (0-> disabled)
1461  * - encoding: Set by user.
1462  * - decoding: unused
1463  */
1464  float temporal_cplx_masking;
1465 
1466  /**
1467  * spatial complexity masking (0-> disabled)
1468  * - encoding: Set by user.
1469  * - decoding: unused
1470  */
1471  float spatial_cplx_masking;
1472 
1473  /**
1474  * p block masking (0-> disabled)
1475  * - encoding: Set by user.
1476  * - decoding: unused
1477  */
1478  float p_masking;
1479 
1480  /**
1481  * darkness masking (0-> disabled)
1482  * - encoding: Set by user.
1483  * - decoding: unused
1484  */
1485  float dark_masking;
1486 
1487  /**
1488  * slice count
1489  * - encoding: Set by libavcodec.
1490  * - decoding: Set by user (or 0).
1491  */
1492  int slice_count;
1493  /**
1494  * prediction method (needed for huffyuv)
1495  * - encoding: Set by user.
1496  * - decoding: unused
1497  */
1499 #define FF_PRED_LEFT 0
1500 #define FF_PRED_PLANE 1
1501 #define FF_PRED_MEDIAN 2
1502 
1503  /**
1504  * slice offsets in the frame in bytes
1505  * - encoding: Set/allocated by libavcodec.
1506  * - decoding: Set/allocated by user (or NULL).
1507  */
1508  int *slice_offset;
1509 
1510  /**
1511  * sample aspect ratio (0 if unknown)
1512  * That is the width of a pixel divided by the height of the pixel.
1513  * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1514  * - encoding: Set by user.
1515  * - decoding: Set by libavcodec.
1516  */
1518 
1519  /**
1520  * motion estimation comparison function
1521  * - encoding: Set by user.
1522  * - decoding: unused
1523  */
1524  int me_cmp;
1525  /**
1526  * subpixel motion estimation comparison function
1527  * - encoding: Set by user.
1528  * - decoding: unused
1529  */
1530  int me_sub_cmp;
1531  /**
1532  * macroblock comparison function (not supported yet)
1533  * - encoding: Set by user.
1534  * - decoding: unused
1535  */
1536  int mb_cmp;
1537  /**
1538  * interlaced DCT comparison function
1539  * - encoding: Set by user.
1540  * - decoding: unused
1541  */
1543 #define FF_CMP_SAD 0
1544 #define FF_CMP_SSE 1
1545 #define FF_CMP_SATD 2
1546 #define FF_CMP_DCT 3
1547 #define FF_CMP_PSNR 4
1548 #define FF_CMP_BIT 5
1549 #define FF_CMP_RD 6
1550 #define FF_CMP_ZERO 7
1551 #define FF_CMP_VSAD 8
1552 #define FF_CMP_VSSE 9
1553 #define FF_CMP_NSSE 10
1554 #define FF_CMP_W53 11
1555 #define FF_CMP_W97 12
1556 #define FF_CMP_DCTMAX 13
1557 #define FF_CMP_DCT264 14
1558 #define FF_CMP_CHROMA 256
1559 
1560  /**
1561  * ME diamond size & shape
1562  * - encoding: Set by user.
1563  * - decoding: unused
1564  */
1565  int dia_size;
1566 
1567  /**
1568  * amount of previous MV predictors (2a+1 x 2a+1 square)
1569  * - encoding: Set by user.
1570  * - decoding: unused
1571  */
1573 
1574  /**
1575  * prepass for motion estimation
1576  * - encoding: Set by user.
1577  * - decoding: unused
1578  */
1579  int pre_me;
1580 
1581  /**
1582  * motion estimation prepass comparison function
1583  * - encoding: Set by user.
1584  * - decoding: unused
1585  */
1586  int me_pre_cmp;
1587 
1588  /**
1589  * ME prepass diamond size & shape
1590  * - encoding: Set by user.
1591  * - decoding: unused
1592  */
1593  int pre_dia_size;
1594 
1595  /**
1596  * subpel ME quality
1597  * - encoding: Set by user.
1598  * - decoding: unused
1599  */
1600  int me_subpel_quality;
1601 
1602  /**
1603  * DTG active format information (additional aspect ratio
1604  * information only used in DVB MPEG-2 transport streams)
1605  * 0 if not set.
1606  *
1607  * - encoding: unused
1608  * - decoding: Set by decoder.
1609  */
1611 #define FF_DTG_AFD_SAME 8
1612 #define FF_DTG_AFD_4_3 9
1613 #define FF_DTG_AFD_16_9 10
1614 #define FF_DTG_AFD_14_9 11
1615 #define FF_DTG_AFD_4_3_SP_14_9 13
1616 #define FF_DTG_AFD_16_9_SP_14_9 14
1617 #define FF_DTG_AFD_SP_4_3 15
1618 
1619  /**
1620  * maximum motion estimation search range in subpel units
1621  * If 0 then no limit.
1622  *
1623  * - encoding: Set by user.
1624  * - decoding: unused
1625  */
1626  int me_range;
1627 
1628  /**
1629  * intra quantizer bias
1630  * - encoding: Set by user.
1631  * - decoding: unused
1632  */
1634 #define FF_DEFAULT_QUANT_BIAS 999999
1635 
1636  /**
1637  * inter quantizer bias
1638  * - encoding: Set by user.
1639  * - decoding: unused
1640  */
1641  int inter_quant_bias;
1642 
1643  /**
1644  * slice flags
1645  * - encoding: unused
1646  * - decoding: Set by user.
1647  */
1649 #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
1650 #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
1651 #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
1652 
1653  /**
1654  * XVideo Motion Acceleration
1655  * - encoding: forbidden
1656  * - decoding: set by decoder
1657  */
1658  int xvmc_acceleration;
1659 
1660  /**
1661  * macroblock decision mode
1662  * - encoding: Set by user.
1663  * - decoding: unused
1664  */
1666 #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp
1667 #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits
1668 #define FF_MB_DECISION_RD 2 ///< rate distortion
1669 
1670  /**
1671  * custom intra quantization matrix
1672  * - encoding: Set by user, can be NULL.
1673  * - decoding: Set by libavcodec.
1674  */
1675  uint16_t *intra_matrix;
1676 
1677  /**
1678  * custom inter quantization matrix
1679  * - encoding: Set by user, can be NULL.
1680  * - decoding: Set by libavcodec.
1681  */
1682  uint16_t *inter_matrix;
1683 
1684  /**
1685  * scene change detection threshold
1686  * 0 is default, larger means fewer detected scene changes.
1687  * - encoding: Set by user.
1688  * - decoding: unused
1689  */
1691 
1692  /**
1693  * noise reduction strength
1694  * - encoding: Set by user.
1695  * - decoding: unused
1696  */
1697  int noise_reduction;
1698 
1699  /**
1700  * Motion estimation threshold below which no motion estimation is
1701  * performed, but instead the user specified motion vectors are used.
1702  *
1703  * - encoding: Set by user.
1704  * - decoding: unused
1705  */
1706  int me_threshold;
1707 
1708  /**
1709  * Macroblock threshold below which the user specified macroblock types will be used.
1710  * - encoding: Set by user.
1711  * - decoding: unused
1712  */
1713  int mb_threshold;
1714 
1715  /**
1716  * precision of the intra DC coefficient - 8
1717  * - encoding: Set by user.
1718  * - decoding: unused
1719  */
1720  int intra_dc_precision;
1721 
1722  /**
1723  * Number of macroblock rows at the top which are skipped.
1724  * - encoding: unused
1725  * - decoding: Set by user.
1726  */
1727  int skip_top;
1728 
1729  /**
1730  * Number of macroblock rows at the bottom which are skipped.
1731  * - encoding: unused
1732  * - decoding: Set by user.
1733  */
1734  int skip_bottom;
1735 
1736  /**
1737  * Border processing masking, raises the quantizer for mbs on the borders
1738  * of the picture.
1739  * - encoding: Set by user.
1740  * - decoding: unused
1741  */
1742  float border_masking;
1743 
1744  /**
1745  * minimum MB lagrange multipler
1746  * - encoding: Set by user.
1747  * - decoding: unused
1748  */
1749  int mb_lmin;
1750 
1751  /**
1752  * maximum MB lagrange multipler
1753  * - encoding: Set by user.
1754  * - decoding: unused
1755  */
1756  int mb_lmax;
1757 
1758  /**
1759  *
1760  * - encoding: Set by user.
1761  * - decoding: unused
1762  */
1764 
1765  /**
1766  *
1767  * - encoding: Set by user.
1768  * - decoding: unused
1769  */
1770  int bidir_refine;
1771 
1772  /**
1773  *
1774  * - encoding: Set by user.
1775  * - decoding: unused
1776  */
1777  int brd_scale;
1778 
1779  /**
1780  * minimum GOP size
1781  * - encoding: Set by user.
1782  * - decoding: unused
1783  */
1784  int keyint_min;
1785 
1786  /**
1787  * number of reference frames
1788  * - encoding: Set by user.
1789  * - decoding: Set by lavc.
1790  */
1791  int refs;
1792 
1793  /**
1794  * chroma qp offset from luma
1795  * - encoding: Set by user.
1796  * - decoding: unused
1797  */
1798  int chromaoffset;
1799 
1800  /**
1801  * Multiplied by qscale for each frame and added to scene_change_score.
1802  * - encoding: Set by user.
1803  * - decoding: unused
1804  */
1805  int scenechange_factor;
1806 
1807  /**
1808  *
1809  * Note: Value depends upon the compare function used for fullpel ME.
1810  * - encoding: Set by user.
1811  * - decoding: unused
1812  */
1813  int mv0_threshold;
1814 
1815  /**
1816  * Adjust sensitivity of b_frame_strategy 1.
1817  * - encoding: Set by user.
1818  * - decoding: unused
1819  */
1820  int b_sensitivity;
1821 
1822  /**
1823  * Chromaticity coordinates of the source primaries.
1824  * - encoding: Set by user
1825  * - decoding: Set by libavcodec
1826  */
1828 
1829  /**
1830  * Color Transfer Characteristic.
1831  * - encoding: Set by user
1832  * - decoding: Set by libavcodec
1833  */
1835 
1836  /**
1837  * YUV colorspace type.
1838  * - encoding: Set by user
1839  * - decoding: Set by libavcodec
1840  */
1841  enum AVColorSpace colorspace;
1842 
1843  /**
1844  * MPEG vs JPEG YUV range.
1845  * - encoding: Set by user
1846  * - decoding: Set by libavcodec
1847  */
1849 
1850  /**
1851  * This defines the location of chroma samples.
1852  * - encoding: Set by user
1853  * - decoding: Set by libavcodec
1854  */
1856 
1857  /**
1858  * Number of slices.
1859  * Indicates number of picture subdivisions. Used for parallelized
1860  * decoding.
1861  * - encoding: Set by user
1862  * - decoding: unused
1863  */
1864  int slices;
1865 
1866  /** Field order
1867  * - encoding: set by libavcodec
1868  * - decoding: Set by user.
1869  */
1871 
1872  /* audio only */
1873  int sample_rate; ///< samples per second
1874  int channels; ///< number of audio channels
1875 
1876  /**
1877  * audio sample format
1878  * - encoding: Set by user.
1879  * - decoding: Set by libavcodec.
1880  */
1881  enum AVSampleFormat sample_fmt; ///< sample format
1882 
1883  /* The following data should not be initialized. */
1884  /**
1885  * Number of samples per channel in an audio frame.
1886  *
1887  * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
1888  * except the last must contain exactly frame_size samples per channel.
1889  * May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
1890  * frame size is not restricted.
1891  * - decoding: may be set by some decoders to indicate constant frame size
1892  */
1893  int frame_size;
1894 
1895  /**
1896  * Frame counter, set by libavcodec.
1897  *
1898  * - decoding: total number of frames returned from the decoder so far.
1899  * - encoding: total number of frames passed to the encoder so far.
1900  *
1901  * @note the counter is not incremented if encoding/decoding resulted in
1902  * an error.
1903  */
1904  int frame_number;
1905 
1906  /**
1907  * number of bytes per packet if constant and known or 0
1908  * Used by some WAV based audio codecs.
1909  */
1910  int block_align;
1911 
1912  /**
1913  * Audio cutoff bandwidth (0 means "automatic")
1914  * - encoding: Set by user.
1915  * - decoding: unused
1916  */
1917  int cutoff;
1918 
1919 #if FF_API_REQUEST_CHANNELS
1920  /**
1921  * Decoder should decode to this many channels if it can (0 for default)
1922  * - encoding: unused
1923  * - decoding: Set by user.
1924  * @deprecated Deprecated in favor of request_channel_layout.
1925  */
1926  attribute_deprecated int request_channels;
1927 #endif
1928 
1929  /**
1930  * Audio channel layout.
1931  * - encoding: set by user.
1932  * - decoding: set by user, may be overwritten by libavcodec.
1933  */
1934  uint64_t channel_layout;
1935 
1936  /**
1937  * Request decoder to use this channel layout if it can (0 for default)
1938  * - encoding: unused
1939  * - decoding: Set by user.
1940  */
1941  uint64_t request_channel_layout;
1942 
1943  /**
1944  * Type of service that the audio stream conveys.
1945  * - encoding: Set by user.
1946  * - decoding: Set by libavcodec.
1947  */
1949 
1950  /**
1951  * desired sample format
1952  * - encoding: Not used.
1953  * - decoding: Set by user.
1954  * Decoder will decode to this format if it can.
1955  */
1957 
1958 #if FF_API_GET_BUFFER
1959  /**
1960  * Called at the beginning of each frame to get a buffer for it.
1961  *
1962  * The function will set AVFrame.data[], AVFrame.linesize[].
1963  * AVFrame.extended_data[] must also be set, but it should be the same as
1964  * AVFrame.data[] except for planar audio with more channels than can fit
1965  * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
1966  * many data pointers as it can hold.
1967  *
1968  * if CODEC_CAP_DR1 is not set then get_buffer() must call
1969  * avcodec_default_get_buffer() instead of providing buffers allocated by
1970  * some other means.
1971  *
1972  * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
1973  * need it. avcodec_default_get_buffer() aligns the output buffer properly,
1974  * but if get_buffer() is overridden then alignment considerations should
1975  * be taken into account.
1976  *
1977  * @see avcodec_default_get_buffer()
1978  *
1979  * Video:
1980  *
1981  * If pic.reference is set then the frame will be read later by libavcodec.
1982  * avcodec_align_dimensions2() should be used to find the required width and
1983  * height, as they normally need to be rounded up to the next multiple of 16.
1984  *
1985  * If frame multithreading is used and thread_safe_callbacks is set,
1986  * it may be called from a different thread, but not from more than one at
1987  * once. Does not need to be reentrant.
1988  *
1989  * @see release_buffer(), reget_buffer()
1990  * @see avcodec_align_dimensions2()
1991  *
1992  * Audio:
1993  *
1994  * Decoders request a buffer of a particular size by setting
1995  * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
1996  * however, utilize only part of the buffer by setting AVFrame.nb_samples
1997  * to a smaller value in the output frame.
1998  *
1999  * Decoders cannot use the buffer after returning from
2000  * avcodec_decode_audio4(), so they will not call release_buffer(), as it
2001  * is assumed to be released immediately upon return. In some rare cases,
2002  * a decoder may need to call get_buffer() more than once in a single
2003  * call to avcodec_decode_audio4(). In that case, when get_buffer() is
2004  * called again after it has already been called once, the previously
2005  * acquired buffer is assumed to be released at that time and may not be
2006  * reused by the decoder.
2007  *
2008  * As a convenience, av_samples_get_buffer_size() and
2009  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
2010  * functions to find the required data size and to fill data pointers and
2011  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2012  * since all planes must be the same size.
2013  *
2014  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2015  *
2016  * - encoding: unused
2017  * - decoding: Set by libavcodec, user can override.
2018  *
2019  * @deprecated use get_buffer2()
2020  */
2022  int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
2023 
2024  /**
2025  * Called to release buffers which were allocated with get_buffer.
2026  * A released buffer can be reused in get_buffer().
2027  * pic.data[*] must be set to NULL.
2028  * May be called from a different thread if frame multithreading is used,
2029  * but not by more than one thread at once, so does not need to be reentrant.
2030  * - encoding: unused
2031  * - decoding: Set by libavcodec, user can override.
2032  *
2033  * @deprecated custom freeing callbacks should be set from get_buffer2()
2034  */
2036  void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
2037 
2038  /**
2039  * Called at the beginning of a frame to get cr buffer for it.
2040  * Buffer type (size, hints) must be the same. libavcodec won't check it.
2041  * libavcodec will pass previous buffer in pic, function should return
2042  * same buffer or new buffer with old frame "painted" into it.
2043  * If pic.data[0] == NULL must behave like get_buffer().
2044  * if CODEC_CAP_DR1 is not set then reget_buffer() must call
2045  * avcodec_default_reget_buffer() instead of providing buffers allocated by
2046  * some other means.
2047  * - encoding: unused
2048  * - decoding: Set by libavcodec, user can override.
2049  */
2051  int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
2052 #endif
2053 
2054  /**
2055  * This callback is called at the beginning of each frame to get data
2056  * buffer(s) for it. There may be one contiguous buffer for all the data or
2057  * there may be a buffer per each data plane or anything in between. What
2058  * this means is, you may set however many entries in buf[] you feel necessary.
2059  * Each buffer must be reference-counted using the AVBuffer API (see description
2060  * of buf[] below).
2061  *
2062  * The following fields will be set in the frame before this callback is
2063  * called:
2064  * - format
2065  * - width, height (video only)
2066  * - sample_rate, channel_layout, nb_samples (audio only)
2067  * Their values may differ from the corresponding values in
2068  * AVCodecContext. This callback must use the frame values, not the codec
2069  * context values, to calculate the required buffer size.
2070  *
2071  * This callback must fill the following fields in the frame:
2072  * - data[]
2073  * - linesize[]
2074  * - extended_data:
2075  * * if the data is planar audio with more than 8 channels, then this
2076  * callback must allocate and fill extended_data to contain all pointers
2077  * to all data planes. data[] must hold as many pointers as it can.
2078  * extended_data must be allocated with av_malloc() and will be freed in
2079  * av_frame_unref().
2080  * * otherwise exended_data must point to data
2081  * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2082  * the frame's data and extended_data pointers must be contained in these. That
2083  * is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2084  * AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2085  * and av_buffer_ref().
2086  * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2087  * this callback and filled with the extra buffers if there are more
2088  * buffers than buf[] can hold. extended_buf will be freed in
2089  * av_frame_unref().
2090  *
2091  * If CODEC_CAP_DR1 is not set then get_buffer2() must call
2092  * avcodec_default_get_buffer2() instead of providing buffers allocated by
2093  * some other means.
2094  *
2095  * Each data plane must be aligned to the maximum required by the target
2096  * CPU.
2097  *
2098  * @see avcodec_default_get_buffer2()
2099  *
2100  * Video:
2101  *
2102  * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2103  * (read and/or written to if it is writable) later by libavcodec.
2104  *
2105  * If CODEC_FLAG_EMU_EDGE is not set in s->flags, the buffer must contain an
2106  * edge of the size returned by avcodec_get_edge_width() on all sides.
2107  *
2108  * avcodec_align_dimensions2() should be used to find the required width and
2109  * height, as they normally need to be rounded up to the next multiple of 16.
2110  *
2111  * If frame multithreading is used and thread_safe_callbacks is set,
2112  * this callback may be called from a different thread, but not from more
2113  * than one at once. Does not need to be reentrant.
2114  *
2115  * @see avcodec_align_dimensions2()
2116  *
2117  * Audio:
2118  *
2119  * Decoders request a buffer of a particular size by setting
2120  * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2121  * however, utilize only part of the buffer by setting AVFrame.nb_samples
2122  * to a smaller value in the output frame.
2123  *
2124  * As a convenience, av_samples_get_buffer_size() and
2125  * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2126  * functions to find the required data size and to fill data pointers and
2127  * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2128  * since all planes must be the same size.
2129  *
2130  * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2131  *
2132  * - encoding: unused
2133  * - decoding: Set by libavcodec, user can override.
2134  */
2135  int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2136 
2137  /**
2138  * If non-zero, the decoded audio and video frames returned from
2139  * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2140  * and are valid indefinitely. The caller must free them with
2141  * av_frame_unref() when they are not needed anymore.
2142  * Otherwise, the decoded frames must not be freed by the caller and are
2143  * only valid until the next decode call.
2144  *
2145  * - encoding: unused
2146  * - decoding: set by the caller before avcodec_open2().
2147  */
2148  int refcounted_frames;
2149 
2150  /* - encoding parameters */
2151  float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2152  float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
2153 
2154  /**
2155  * minimum quantizer
2156  * - encoding: Set by user.
2157  * - decoding: unused
2158  */
2159  int qmin;
2160 
2161  /**
2162  * maximum quantizer
2163  * - encoding: Set by user.
2164  * - decoding: unused
2165  */
2166  int qmax;
2167 
2168  /**
2169  * maximum quantizer difference between frames
2170  * - encoding: Set by user.
2171  * - decoding: unused
2172  */
2173  int max_qdiff;
2174 
2175  /**
2176  * ratecontrol qmin qmax limiting method
2177  * 0-> clipping, 1-> use a nice continuous function to limit qscale wthin qmin/qmax.
2178  * - encoding: Set by user.
2179  * - decoding: unused
2180  */
2181  float rc_qsquish;
2184  int rc_qmod_freq;
2185 
2186  /**
2187  * decoder bitstream buffer size
2188  * - encoding: Set by user.
2189  * - decoding: unused
2190  */
2191  int rc_buffer_size;
2192 
2193  /**
2194  * ratecontrol override, see RcOverride
2195  * - encoding: Allocated/set/freed by user.
2196  * - decoding: unused
2197  */
2200 
2201  /**
2202  * rate control equation
2203  * - encoding: Set by user
2204  * - decoding: unused
2205  */
2206  const char *rc_eq;
2207 
2208  /**
2209  * maximum bitrate
2210  * - encoding: Set by user.
2211  * - decoding: unused
2212  */
2213  int rc_max_rate;
2214 
2215  /**
2216  * minimum bitrate
2217  * - encoding: Set by user.
2218  * - decoding: unused
2219  */
2220  int rc_min_rate;
2222  float rc_buffer_aggressivity;
2223 
2224  /**
2225  * initial complexity for pass1 ratecontrol
2226  * - encoding: Set by user.
2227  * - decoding: unused
2228  */
2229  float rc_initial_cplx;
2230 
2231  /**
2232  * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2233  * - encoding: Set by user.
2234  * - decoding: unused.
2235  */
2237 
2238  /**
2239  * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2240  * - encoding: Set by user.
2241  * - decoding: unused.
2242  */
2244 
2245  /**
2246  * Number of bits which should be loaded into the rc buffer before decoding starts.
2247  * - encoding: Set by user.
2248  * - decoding: unused
2249  */
2252 #define FF_CODER_TYPE_VLC 0
2253 #define FF_CODER_TYPE_AC 1
2254 #define FF_CODER_TYPE_RAW 2
2255 #define FF_CODER_TYPE_RLE 3
2256 #define FF_CODER_TYPE_DEFLATE 4
2257  /**
2258  * coder type
2259  * - encoding: Set by user.
2260  * - decoding: unused
2261  */
2262  int coder_type;
2263 
2264  /**
2265  * context model
2266  * - encoding: Set by user.
2267  * - decoding: unused
2268  */
2269  int context_model;
2270 
2271  /**
2272  * minimum Lagrange multipler
2273  * - encoding: Set by user.
2274  * - decoding: unused
2275  */
2276  int lmin;
2277 
2278  /**
2279  * maximum Lagrange multipler
2280  * - encoding: Set by user.
2281  * - decoding: unused
2282  */
2283  int lmax;
2284 
2285  /**
2286  * frame skip threshold
2287  * - encoding: Set by user.
2288  * - decoding: unused
2289  */
2291 
2292  /**
2293  * frame skip factor
2294  * - encoding: Set by user.
2295  * - decoding: unused
2296  */
2297  int frame_skip_factor;
2298 
2299  /**
2300  * frame skip exponent
2301  * - encoding: Set by user.
2302  * - decoding: unused
2303  */
2304  int frame_skip_exp;
2305 
2306  /**
2307  * frame skip comparison function
2308  * - encoding: Set by user.
2309  * - decoding: unused
2310  */
2311  int frame_skip_cmp;
2312 
2313  /**
2314  * trellis RD quantization
2315  * - encoding: Set by user.
2316  * - decoding: unused
2317  */
2318  int trellis;
2319 
2320  /**
2321  * - encoding: Set by user.
2322  * - decoding: unused
2323  */
2325 
2326  /**
2327  * - encoding: Set by user.
2328  * - decoding: unused
2329  */
2331 
2332  /**
2333  * GOP timecode frame start number
2334  * - encoding: Set by user, in non drop frame format
2335  * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2336  */
2337  int64_t timecode_frame_start;
2338 
2339  /* The RTP callback: This function is called */
2340  /* every time the encoder has a packet to send. */
2341  /* It depends on the encoder if the data starts */
2342  /* with a Start Code (it should). H.263 does. */
2343  /* mb_nb contains the number of macroblocks */
2344  /* encoded in the RTP payload. */
2345  void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2347  int rtp_payload_size; /* The size of the RTP payload: the coder will */
2348  /* do its best to deliver a chunk with size */
2349  /* below rtp_payload_size, the chunk will start */
2350  /* with a start code on some codecs like H.263. */
2351  /* This doesn't take account of any particular */
2352  /* headers inside the transmitted RTP payload. */
2353 
2354  /* statistics, used for 2-pass encoding */
2355  int mv_bits;
2359  int i_count;
2360  int p_count;
2362  int misc_bits;
2363 
2364  /**
2365  * number of bits used for the previously encoded frame
2366  * - encoding: Set by libavcodec.
2367  * - decoding: unused
2368  */
2369  int frame_bits;
2370 
2371  /**
2372  * pass1 encoding statistics output buffer
2373  * - encoding: Set by libavcodec.
2374  * - decoding: unused
2375  */
2376  char *stats_out;
2377 
2378  /**
2379  * pass2 encoding statistics input buffer
2380  * Concatenated stuff from stats_out of pass1 should be placed here.
2381  * - encoding: Allocated/set/freed by user.
2382  * - decoding: unused
2383  */
2384  char *stats_in;
2385 
2386  /**
2387  * Work around bugs in encoders which sometimes cannot be detected automatically.
2388  * - encoding: Set by user
2389  * - decoding: Set by user
2390  */
2392 #define FF_BUG_AUTODETECT 1 ///< autodetection
2393 #define FF_BUG_OLD_MSMPEG4 2
2394 #define FF_BUG_XVID_ILACE 4
2395 #define FF_BUG_UMP4 8
2396 #define FF_BUG_NO_PADDING 16
2397 #define FF_BUG_AMV 32
2398 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2399 #define FF_BUG_QPEL_CHROMA 64
2400 #define FF_BUG_STD_QPEL 128
2401 #define FF_BUG_QPEL_CHROMA2 256
2402 #define FF_BUG_DIRECT_BLOCKSIZE 512
2403 #define FF_BUG_EDGE 1024
2404 #define FF_BUG_HPEL_CHROMA 2048
2405 #define FF_BUG_DC_CLIP 4096
2406 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
2407 #define FF_BUG_TRUNCATED 16384
2408 
2409  /**
2410  * strictly follow the standard (MPEG4, ...).
2411  * - encoding: Set by user.
2412  * - decoding: Set by user.
2413  * Setting this to STRICT or higher means the encoder and decoder will
2414  * generally do stupid things, whereas setting it to unofficial or lower
2415  * will mean the encoder might produce output that is not supported by all
2416  * spec-compliant decoders. Decoders don't differentiate between normal,
2417  * unofficial and experimental (that is, they always try to decode things
2418  * when they can) unless they are explicitly asked to behave stupidly
2419  * (=strictly conform to the specs)
2420  */
2422 #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software.
2423 #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
2424 #define FF_COMPLIANCE_NORMAL 0
2425 #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions
2426 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2427 
2428  /**
2429  * error concealment flags
2430  * - encoding: unused
2431  * - decoding: Set by user.
2432  */
2434 #define FF_EC_GUESS_MVS 1
2435 #define FF_EC_DEBLOCK 2
2436 
2437  /**
2438  * debug
2439  * - encoding: Set by user.
2440  * - decoding: Set by user.
2441  */
2442  int debug;
2443 #define FF_DEBUG_PICT_INFO 1
2444 #define FF_DEBUG_RC 2
2445 #define FF_DEBUG_BITSTREAM 4
2446 #define FF_DEBUG_MB_TYPE 8
2447 #define FF_DEBUG_QP 16
2448 #define FF_DEBUG_MV 32
2449 #define FF_DEBUG_DCT_COEFF 0x00000040
2450 #define FF_DEBUG_SKIP 0x00000080
2451 #define FF_DEBUG_STARTCODE 0x00000100
2452 #define FF_DEBUG_PTS 0x00000200
2453 #define FF_DEBUG_ER 0x00000400
2454 #define FF_DEBUG_MMCO 0x00000800
2455 #define FF_DEBUG_BUGS 0x00001000
2456 #define FF_DEBUG_VIS_QP 0x00002000
2457 #define FF_DEBUG_VIS_MB_TYPE 0x00004000
2458 #define FF_DEBUG_BUFFERS 0x00008000
2459 #define FF_DEBUG_THREADS 0x00010000
2460 
2461  /**
2462  * debug
2463  * - encoding: Set by user.
2464  * - decoding: Set by user.
2465  */
2467 #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
2468 #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames
2469 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2470 
2471  /**
2472  * Error recognition; may misdetect some more or less valid parts as errors.
2473  * - encoding: unused
2474  * - decoding: Set by user.
2475  */
2477 #define AV_EF_CRCCHECK (1<<0) ///< verify embedded CRCs
2478 #define AV_EF_BITSTREAM (1<<1) ///< detect bitstream specification deviations
2479 #define AV_EF_BUFFER (1<<2) ///< detect improper bitstream length
2480 #define AV_EF_EXPLODE (1<<3) ///< abort decoding on minor error detection
2482 #define AV_EF_CAREFUL (1<<16) ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors
2483 #define AV_EF_COMPLIANT (1<<17) ///< consider all spec non compliancies as errors
2484 #define AV_EF_AGGRESSIVE (1<<18) ///< consider things that a sane encoder should not do as an error
2485 
2486 
2487  /**
2488  * opaque 64bit number (generally a PTS) that will be reordered and
2489  * output in AVFrame.reordered_opaque
2490  * @deprecated in favor of pkt_pts
2491  * - encoding: unused
2492  * - decoding: Set by user.
2493  */
2494  int64_t reordered_opaque;
2495 
2496  /**
2497  * Hardware accelerator in use
2498  * - encoding: unused.
2499  * - decoding: Set by libavcodec
2500  */
2501  struct AVHWAccel *hwaccel;
2502 
2503  /**
2504  * Hardware accelerator context.
2505  * For some hardware accelerators, a global context needs to be
2506  * provided by the user. In that case, this holds display-dependent
2507  * data FFmpeg cannot instantiate itself. Please refer to the
2508  * FFmpeg HW accelerator documentation to know how to fill this
2509  * is. e.g. for VA API, this is a struct vaapi_context.
2510  * - encoding: unused
2511  * - decoding: Set by user
2512  */
2513  void *hwaccel_context;
2514 
2515  /**
2516  * error
2517  * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
2518  * - decoding: unused
2519  */
2520  uint64_t error[AV_NUM_DATA_POINTERS];
2521 
2522  /**
2523  * DCT algorithm, see FF_DCT_* below
2524  * - encoding: Set by user.
2525  * - decoding: unused
2526  */
2528 #define FF_DCT_AUTO 0
2529 #define FF_DCT_FASTINT 1
2530 #define FF_DCT_INT 2
2531 #define FF_DCT_MMX 3
2532 #define FF_DCT_ALTIVEC 5
2533 #define FF_DCT_FAAN 6
2534 
2535  /**
2536  * IDCT algorithm, see FF_IDCT_* below.
2537  * - encoding: Set by user.
2538  * - decoding: Set by user.
2539  */
2541 #define FF_IDCT_AUTO 0
2542 #define FF_IDCT_INT 1
2543 #define FF_IDCT_SIMPLE 2
2544 #define FF_IDCT_SIMPLEMMX 3
2545 #define FF_IDCT_ARM 7
2546 #define FF_IDCT_ALTIVEC 8
2547 #define FF_IDCT_SH4 9
2548 #define FF_IDCT_SIMPLEARM 10
2549 #define FF_IDCT_IPP 13
2550 #define FF_IDCT_XVIDMMX 14
2551 #define FF_IDCT_SIMPLEARMV5TE 16
2552 #define FF_IDCT_SIMPLEARMV6 17
2553 #define FF_IDCT_SIMPLEVIS 18
2554 #define FF_IDCT_FAAN 20
2555 #define FF_IDCT_SIMPLENEON 22
2556 #define FF_IDCT_SIMPLEALPHA 23
2557 
2558  /**
2559  * bits per sample/pixel from the demuxer (needed for huffyuv).
2560  * - encoding: Set by libavcodec.
2561  * - decoding: Set by user.
2562  */
2564 
2565  /**
2566  * Bits per sample/pixel of internal libavcodec pixel/sample format.
2567  * - encoding: set by user.
2568  * - decoding: set by libavcodec.
2569  */
2570  int bits_per_raw_sample;
2571 
2572 #if FF_API_LOWRES
2573  /**
2574  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2575  * - encoding: unused
2576  * - decoding: Set by user.
2577  * Code outside libavcodec should access this field using:
2578  * av_codec_{get,set}_lowres(avctx)
2579  */
2580  int lowres;
2581 #endif
2582 
2583  /**
2584  * the picture in the bitstream
2585  * - encoding: Set by libavcodec.
2586  * - decoding: Set by libavcodec.
2587  */
2589 
2590  /**
2591  * thread count
2592  * is used to decide how many independent tasks should be passed to execute()
2593  * - encoding: Set by user.
2594  * - decoding: Set by user.
2595  */
2596  int thread_count;
2597 
2598  /**
2599  * Which multithreading methods to use.
2600  * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2601  * so clients which cannot provide future frames should not use it.
2602  *
2603  * - encoding: Set by user, otherwise the default is used.
2604  * - decoding: Set by user, otherwise the default is used.
2605  */
2607 #define FF_THREAD_FRAME 1 ///< Decode more than one frame at once
2608 #define FF_THREAD_SLICE 2 ///< Decode more than one part of a single frame at once
2609 
2610  /**
2611  * Which multithreading methods are in use by the codec.
2612  * - encoding: Set by libavcodec.
2613  * - decoding: Set by libavcodec.
2614  */
2615  int active_thread_type;
2616 
2617  /**
2618  * Set by the client if its custom get_buffer() callback can be called
2619  * synchronously from another thread, which allows faster multithreaded decoding.
2620  * draw_horiz_band() will be called from other threads regardless of this setting.
2621  * Ignored if the default get_buffer() is used.
2622  * - encoding: Set by user.
2623  * - decoding: Set by user.
2624  */
2626 
2627  /**
2628  * The codec may call this to execute several independent things.
2629  * It will return only after finishing all tasks.
2630  * The user may replace this with some multithreaded implementation,
2631  * the default implementation will execute the parts serially.
2632  * @param count the number of things to execute
2633  * - encoding: Set by libavcodec, user can override.
2634  * - decoding: Set by libavcodec, user can override.
2635  */
2636  int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
2637 
2638  /**
2639  * The codec may call this to execute several independent things.
2640  * It will return only after finishing all tasks.
2641  * The user may replace this with some multithreaded implementation,
2642  * the default implementation will execute the parts serially.
2643  * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
2644  * @param c context passed also to func
2645  * @param count the number of things to execute
2646  * @param arg2 argument passed unchanged to func
2647  * @param ret return values of executed functions, must have space for "count" values. May be NULL.
2648  * @param func function that will be called count times, with jobnr from 0 to count-1.
2649  * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
2650  * two instances of func executing at the same time will have the same threadnr.
2651  * @return always 0 currently, but code should handle a future improvement where when any call to func
2652  * returns < 0 no further calls to func may be done and < 0 is returned.
2653  * - encoding: Set by libavcodec, user can override.
2654  * - decoding: Set by libavcodec, user can override.
2655  */
2656  int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
2657 
2658  /**
2659  * thread opaque
2660  * Can be used by execute() to store some per AVCodecContext stuff.
2661  * - encoding: set by execute()
2662  * - decoding: set by execute()
2663  */
2664  void *thread_opaque;
2665 
2666  /**
2667  * noise vs. sse weight for the nsse comparsion function
2668  * - encoding: Set by user.
2669  * - decoding: unused
2670  */
2671  int nsse_weight;
2672 
2673  /**
2674  * profile
2675  * - encoding: Set by user.
2676  * - decoding: Set by libavcodec.
2677  */
2678  int profile;
2679 #define FF_PROFILE_UNKNOWN -99
2680 #define FF_PROFILE_RESERVED -100
2682 #define FF_PROFILE_AAC_MAIN 0
2683 #define FF_PROFILE_AAC_LOW 1
2684 #define FF_PROFILE_AAC_SSR 2
2685 #define FF_PROFILE_AAC_LTP 3
2686 #define FF_PROFILE_AAC_HE 4
2687 #define FF_PROFILE_AAC_HE_V2 28
2688 #define FF_PROFILE_AAC_LD 22
2689 #define FF_PROFILE_AAC_ELD 38
2690 #define FF_PROFILE_MPEG2_AAC_LOW 128
2691 #define FF_PROFILE_MPEG2_AAC_HE 131
2693 #define FF_PROFILE_DTS 20
2694 #define FF_PROFILE_DTS_ES 30
2695 #define FF_PROFILE_DTS_96_24 40
2696 #define FF_PROFILE_DTS_HD_HRA 50
2697 #define FF_PROFILE_DTS_HD_MA 60
2699 #define FF_PROFILE_MPEG2_422 0
2700 #define FF_PROFILE_MPEG2_HIGH 1
2701 #define FF_PROFILE_MPEG2_SS 2
2702 #define FF_PROFILE_MPEG2_SNR_SCALABLE 3
2703 #define FF_PROFILE_MPEG2_MAIN 4
2704 #define FF_PROFILE_MPEG2_SIMPLE 5
2706 #define FF_PROFILE_H264_CONSTRAINED (1<<9) // 8+1; constraint_set1_flag
2707 #define FF_PROFILE_H264_INTRA (1<<11) // 8+3; constraint_set3_flag
2709 #define FF_PROFILE_H264_BASELINE 66
2710 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
2711 #define FF_PROFILE_H264_MAIN 77
2712 #define FF_PROFILE_H264_EXTENDED 88
2713 #define FF_PROFILE_H264_HIGH 100
2714 #define FF_PROFILE_H264_HIGH_10 110
2715 #define FF_PROFILE_H264_HIGH_10_INTRA (110|FF_PROFILE_H264_INTRA)
2716 #define FF_PROFILE_H264_HIGH_422 122
2717 #define FF_PROFILE_H264_HIGH_422_INTRA (122|FF_PROFILE_H264_INTRA)
2718 #define FF_PROFILE_H264_HIGH_444 144
2719 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE 244
2720 #define FF_PROFILE_H264_HIGH_444_INTRA (244|FF_PROFILE_H264_INTRA)
2721 #define FF_PROFILE_H264_CAVLC_444 44
2723 #define FF_PROFILE_VC1_SIMPLE 0
2724 #define FF_PROFILE_VC1_MAIN 1
2725 #define FF_PROFILE_VC1_COMPLEX 2
2726 #define FF_PROFILE_VC1_ADVANCED 3
2728 #define FF_PROFILE_MPEG4_SIMPLE 0
2729 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE 1
2730 #define FF_PROFILE_MPEG4_CORE 2
2731 #define FF_PROFILE_MPEG4_MAIN 3
2732 #define FF_PROFILE_MPEG4_N_BIT 4
2733 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE 5
2734 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION 6
2735 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE 7
2736 #define FF_PROFILE_MPEG4_HYBRID 8
2737 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME 9
2738 #define FF_PROFILE_MPEG4_CORE_SCALABLE 10
2739 #define FF_PROFILE_MPEG4_ADVANCED_CODING 11
2740 #define FF_PROFILE_MPEG4_ADVANCED_CORE 12
2741 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
2742 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO 14
2743 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE 15
2745 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0 0
2746 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1 1
2747 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION 2
2748 #define FF_PROFILE_JPEG2000_DCINEMA_2K 3
2749 #define FF_PROFILE_JPEG2000_DCINEMA_4K 4
2750 
2751  /**
2752  * level
2753  * - encoding: Set by user.
2754  * - decoding: Set by libavcodec.
2755  */
2756  int level;
2757 #define FF_LEVEL_UNKNOWN -99
2758 
2759  /**
2760  * Skip loop filtering for selected frames.
2761  * - encoding: unused
2762  * - decoding: Set by user.
2763  */
2765 
2766  /**
2767  * Skip IDCT/dequantization for selected frames.
2768  * - encoding: unused
2769  * - decoding: Set by user.
2770  */
2771  enum AVDiscard skip_idct;
2772 
2773  /**
2774  * Skip decoding for selected frames.
2775  * - encoding: unused
2776  * - decoding: Set by user.
2777  */
2778  enum AVDiscard skip_frame;
2779 
2780  /**
2781  * Header containing style information for text subtitles.
2782  * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
2783  * [Script Info] and [V4+ Styles] section, plus the [Events] line and
2784  * the Format line following. It shouldn't include any Dialogue line.
2785  * - encoding: Set/allocated/freed by user (before avcodec_open2())
2786  * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
2787  */
2790 
2791  /**
2792  * Simulates errors in the bitstream to test error concealment.
2793  * - encoding: Set by user.
2794  * - decoding: unused
2795  */
2796  int error_rate;
2797 
2798  /**
2799  * Current packet as passed into the decoder, to avoid having
2800  * to pass the packet into every function. Currently only valid
2801  * inside lavc and get/release_buffer callbacks.
2802  * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
2803  * - encoding: unused
2804  */
2805  AVPacket *pkt;
2806 
2807  /**
2808  * VBV delay coded in the last frame (in periods of a 27 MHz clock).
2809  * Used for compliant TS muxing.
2810  * - encoding: Set by libavcodec.
2811  * - decoding: unused.
2812  */
2813  uint64_t vbv_delay;
2814 
2815  /**
2816  * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
2817  * Code outside libavcodec should access this field using:
2818  * av_codec_{get,set}_pkt_timebase(avctx)
2819  * - encoding unused.
2820  * - decoding set by user.
2821  */
2823 
2824  /**
2825  * AVCodecDescriptor
2826  * Code outside libavcodec should access this field using:
2827  * av_codec_{get,set}_codec_descriptor(avctx)
2828  * - encoding: unused.
2829  * - decoding: set by libavcodec.
2830  */
2832 
2833 #if !FF_API_LOWRES
2834  /**
2835  * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2836  * - encoding: unused
2837  * - decoding: Set by user.
2838  * Code outside libavcodec should access this field using:
2839  * av_codec_{get,set}_lowres(avctx)
2840  */
2841  int lowres;
2842 #endif
2843 
2844  /**
2845  * Current statistics for PTS correction.
2846  * - decoding: maintained and used by libavcodec, not intended to be used by user apps
2847  * - encoding: unused
2848  */
2849  int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
2850  int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
2851  int64_t pts_correction_last_pts; /// PTS of the last frame
2852  int64_t pts_correction_last_dts; /// DTS of the last frame
2853 
2854  /**
2855  * Character encoding of the input subtitles file.
2856  * - decoding: set by user
2857  * - encoding: unused
2858  */
2859  char *sub_charenc;
2860 
2861  /**
2862  * Subtitles character encoding mode. Formats or codecs might be adjusting
2863  * this setting (if they are doing the conversion themselves for instance).
2864  * - decoding: set by libavcodec
2865  * - encoding: unused
2866  */
2868 #define FF_SUB_CHARENC_MODE_DO_NOTHING -1 ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance)
2869 #define FF_SUB_CHARENC_MODE_AUTOMATIC 0 ///< libavcodec will select the mode itself
2870 #define FF_SUB_CHARENC_MODE_PRE_DECODER 1 ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv
2871 
2872  /**
2873  * Skip processing alpha if supported by codec.
2874  * Note that if the format uses pre-multiplied alpha (common with VP6,
2875  * and recommended due to better video quality/compression)
2876  * the image will look as if alpha-blended onto a black background.
2877  * However for formats that do not use pre-multiplied alpha
2878  * there might be serious artefacts (though e.g. libswscale currently
2879  * assumes pre-multiplied alpha anyway).
2880  * Code outside libavcodec should access this field using AVOptions
2881  *
2882  * - decoding: set by user
2883  * - encoding: unused
2884  */
2885  int skip_alpha;
2886 
2887  /**
2888  * Number of samples to skip after a discontinuity
2889  * - decoding: unused
2890  * - encoding: set by libavcodec
2891  */
2892  int seek_preroll;
2893 } AVCodecContext;
2894 
2897 
2900 
2901 int av_codec_get_lowres(const AVCodecContext *avctx);
2902 void av_codec_set_lowres(AVCodecContext *avctx, int val);
2903 
2904 int av_codec_get_seek_preroll(const AVCodecContext *avctx);
2905 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
2906 
2907 /**
2908  * AVProfile.
2909  */
2910 typedef struct AVProfile {
2911  int profile;
2912  const char *name; ///< short name for the profile
2913 } AVProfile;
2914 
2915 typedef struct AVCodecDefault AVCodecDefault;
2916 
2917 struct AVSubtitle;
2918 
2919 /**
2920  * AVCodec.
2921  */
2922 typedef struct AVCodec {
2923  /**
2924  * Name of the codec implementation.
2925  * The name is globally unique among encoders and among decoders (but an
2926  * encoder and a decoder can share the same name).
2927  * This is the primary way to find a codec from the user perspective.
2928  */
2929  const char *name;
2930  /**
2931  * Descriptive name for the codec, meant to be more human readable than name.
2932  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
2933  */
2934  const char *long_name;
2936  enum AVCodecID id;
2937  /**
2938  * Codec capabilities.
2939  * see CODEC_CAP_*
2940  */
2942  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
2943  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
2944  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
2945  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
2946  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
2947 #if FF_API_LOWRES
2948  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
2949 #endif
2950  const AVClass *priv_class; ///< AVClass for the private context
2951  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
2952 
2953  /*****************************************************************
2954  * No fields below this line are part of the public API. They
2955  * may not be used outside of libavcodec and can be changed and
2956  * removed at will.
2957  * New public fields should be added right above.
2958  *****************************************************************
2959  */
2961  struct AVCodec *next;
2962  /**
2963  * @name Frame-level threading support functions
2964  * @{
2965  */
2966  /**
2967  * If defined, called on thread contexts when they are created.
2968  * If the codec allocates writable tables in init(), re-allocate them here.
2969  * priv_data will be set to a copy of the original.
2970  */
2971  int (*init_thread_copy)(AVCodecContext *);
2972  /**
2973  * Copy necessary context variables from a previous thread context to the current one.
2974  * If not defined, the next thread will start automatically; otherwise, the codec
2975  * must call ff_thread_finish_setup().
2976  *
2977  * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
2978  */
2980  /** @} */
2981 
2982  /**
2983  * Private codec-specific defaults.
2984  */
2985  const AVCodecDefault *defaults;
2986 
2987  /**
2988  * Initialize codec static data, called from avcodec_register().
2989  */
2990  void (*init_static_data)(struct AVCodec *codec);
2993  int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
2994  const struct AVSubtitle *sub);
2995  /**
2996  * Encode data to an AVPacket.
2997  *
2998  * @param avctx codec context
2999  * @param avpkt output AVPacket (may contain a user-provided buffer)
3000  * @param[in] frame AVFrame containing the raw data to be encoded
3001  * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3002  * non-empty packet was returned in avpkt.
3003  * @return 0 on success, negative error code on failure
3004  */
3005  int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3006  int *got_packet_ptr);
3007  int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3008  int (*close)(AVCodecContext *);
3009  /**
3010  * Flush buffers.
3011  * Will be called when seeking
3012  */
3013  void (*flush)(AVCodecContext *);
3014 } AVCodec;
3015 
3016 int av_codec_get_max_lowres(const AVCodec *codec);
3017 
3018 /**
3019  * AVHWAccel.
3020  */
3021 typedef struct AVHWAccel {
3022  /**
3023  * Name of the hardware accelerated codec.
3024  * The name is globally unique among encoders and among decoders (but an
3025  * encoder and a decoder can share the same name).
3026  */
3027  const char *name;
3028 
3029  /**
3030  * Type of codec implemented by the hardware accelerator.
3031  *
3032  * See AVMEDIA_TYPE_xxx
3033  */
3034  enum AVMediaType type;
3035 
3036  /**
3037  * Codec implemented by the hardware accelerator.
3038  *
3039  * See AV_CODEC_ID_xxx
3040  */
3041  enum AVCodecID id;
3042 
3043  /**
3044  * Supported pixel format.
3045  *
3046  * Only hardware accelerated formats are supported here.
3047  */
3048  enum AVPixelFormat pix_fmt;
3049 
3050  /**
3051  * Hardware accelerated codec capabilities.
3052  * see FF_HWACCEL_CODEC_CAP_*
3053  */
3054  int capabilities;
3056  struct AVHWAccel *next;
3057 
3058  /**
3059  * Called at the beginning of each frame or field picture.
3060  *
3061  * Meaningful frame information (codec specific) is guaranteed to
3062  * be parsed at this point. This function is mandatory.
3063  *
3064  * Note that buf can be NULL along with buf_size set to 0.
3065  * Otherwise, this means the whole frame is available at this point.
3066  *
3067  * @param avctx the codec context
3068  * @param buf the frame data buffer base
3069  * @param buf_size the size of the frame in bytes
3070  * @return zero if successful, a negative value otherwise
3071  */
3072  int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3073 
3074  /**
3075  * Callback for each slice.
3076  *
3077  * Meaningful slice information (codec specific) is guaranteed to
3078  * be parsed at this point. This function is mandatory.
3079  *
3080  * @param avctx the codec context
3081  * @param buf the slice data buffer base
3082  * @param buf_size the size of the slice in bytes
3083  * @return zero if successful, a negative value otherwise
3084  */
3085  int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3086 
3087  /**
3088  * Called at the end of each frame or field picture.
3089  *
3090  * The whole picture is parsed at this point and can now be sent
3091  * to the hardware accelerator. This function is mandatory.
3092  *
3093  * @param avctx the codec context
3094  * @return zero if successful, a negative value otherwise
3095  */
3096  int (*end_frame)(AVCodecContext *avctx);
3097 
3098  /**
3099  * Size of HW accelerator private data.
3100  *
3101  * Private data is allocated with av_mallocz() before
3102  * AVCodecContext.get_buffer() and deallocated after
3103  * AVCodecContext.release_buffer().
3104  */
3105  int priv_data_size;
3106 } AVHWAccel;
3107 
3108 /**
3109  * @defgroup lavc_picture AVPicture
3110  *
3111  * Functions for working with AVPicture
3112  * @{
3113  */
3114 
3115 /**
3116  * Picture data structure.
3117  *
3118  * Up to four components can be stored into it, the last component is
3119  * alpha.
3120  */
3121 typedef struct AVPicture {
3122  uint8_t *data[AV_NUM_DATA_POINTERS]; ///< pointers to the image data planes
3123  int linesize[AV_NUM_DATA_POINTERS]; ///< number of bytes per line
3124 } AVPicture;
3125 
3126 /**
3127  * @}
3128  */
3131  SUBTITLE_NONE,
3133  SUBTITLE_BITMAP, ///< A bitmap, pict will be set
3134 
3135  /**
3136  * Plain text, the text field must be set by the decoder and is
3137  * authoritative. ass and pict fields may contain approximations.
3138  */
3139  SUBTITLE_TEXT,
3140 
3141  /**
3142  * Formatted text, the ass field must be set by the decoder and is
3143  * authoritative. pict and text fields may contain approximations.
3144  */
3145  SUBTITLE_ASS,
3146 };
3148 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3150 typedef struct AVSubtitleRect {
3151  int x; ///< top left corner of pict, undefined when pict is not set
3152  int y; ///< top left corner of pict, undefined when pict is not set
3153  int w; ///< width of pict, undefined when pict is not set
3154  int h; ///< height of pict, undefined when pict is not set
3155  int nb_colors; ///< number of colors in pict, undefined when pict is not set
3156 
3157  /**
3158  * data+linesize for the bitmap of this subtitle.
3159  * can be set for text/ass as well once they where rendered
3160  */
3162  enum AVSubtitleType type;
3164  char *text; ///< 0 terminated plain UTF-8 text
3165 
3166  /**
3167  * 0 terminated ASS/SSA compatible event line.
3168  * The presentation of this is unaffected by the other values in this
3169  * struct.
3170  */
3171  char *ass;
3173  int flags;
3174 } AVSubtitleRect;
3176 typedef struct AVSubtitle {
3177  uint16_t format; /* 0 = graphics */
3178  uint32_t start_display_time; /* relative to packet pts, in ms */
3179  uint32_t end_display_time; /* relative to packet pts, in ms */
3180  unsigned num_rects;
3182  int64_t pts; ///< Same as packet pts, in AV_TIME_BASE
3183 } AVSubtitle;
3184 
3185 /**
3186  * If c is NULL, returns the first registered codec,
3187  * if c is non-NULL, returns the next registered codec after c,
3188  * or NULL if c is the last one.
3189  */
3190 AVCodec *av_codec_next(const AVCodec *c);
3191 
3192 /**
3193  * Return the LIBAVCODEC_VERSION_INT constant.
3194  */
3195 unsigned avcodec_version(void);
3196 
3197 /**
3198  * Return the libavcodec build-time configuration.
3199  */
3200 const char *avcodec_configuration(void);
3201 
3202 /**
3203  * Return the libavcodec license.
3204  */
3205 const char *avcodec_license(void);
3206 
3207 /**
3208  * Register the codec codec and initialize libavcodec.
3209  *
3210  * @warning either this function or avcodec_register_all() must be called
3211  * before any other libavcodec functions.
3212  *
3213  * @see avcodec_register_all()
3214  */
3215 void avcodec_register(AVCodec *codec);
3216 
3217 /**
3218  * Register all the codecs, parsers and bitstream filters which were enabled at
3219  * configuration time. If you do not call this function you can select exactly
3220  * which formats you want to support, by using the individual registration
3221  * functions.
3222  *
3223  * @see avcodec_register
3224  * @see av_register_codec_parser
3225  * @see av_register_bitstream_filter
3226  */
3227 void avcodec_register_all(void);
3228 
3229 
3230 #if FF_API_ALLOC_CONTEXT
3231 /**
3232  * Allocate an AVCodecContext and set its fields to default values. The
3233  * resulting struct can be deallocated by simply calling av_free().
3234  *
3235  * @return An AVCodecContext filled with default values or NULL on failure.
3236  * @see avcodec_get_context_defaults
3237  *
3238  * @deprecated use avcodec_alloc_context3()
3239  */
3241 AVCodecContext *avcodec_alloc_context(void);
3242 
3243 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3244  * we WILL change its arguments and name a few times! */
3246 AVCodecContext *avcodec_alloc_context2(enum AVMediaType);
3247 
3248 /**
3249  * Set the fields of the given AVCodecContext to default values.
3250  *
3251  * @param s The AVCodecContext of which the fields should be set to default values.
3252  * @deprecated use avcodec_get_context_defaults3
3253  */
3255 void avcodec_get_context_defaults(AVCodecContext *s);
3256 
3257 /** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
3258  * we WILL change its arguments and name a few times! */
3260 void avcodec_get_context_defaults2(AVCodecContext *s, enum AVMediaType);
3261 #endif
3262 
3263 /**
3264  * Allocate an AVCodecContext and set its fields to default values. The
3265  * resulting struct can be deallocated by calling avcodec_close() on it followed
3266  * by av_free().
3267  *
3268  * @param codec if non-NULL, allocate private data and initialize defaults
3269  * for the given codec. It is illegal to then call avcodec_open2()
3270  * with a different codec.
3271  * If NULL, then the codec-specific defaults won't be initialized,
3272  * which may result in suboptimal default settings (this is
3273  * important mainly for encoders, e.g. libx264).
3274  *
3275  * @return An AVCodecContext filled with default values or NULL on failure.
3276  * @see avcodec_get_context_defaults
3277  */
3279 
3280 /**
3281  * Set the fields of the given AVCodecContext to default values corresponding
3282  * to the given codec (defaults may be codec-dependent).
3283  *
3284  * Do not call this function if a non-NULL codec has been passed
3285  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3286  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3287  * different codec on this AVCodecContext.
3288  */
3290 
3291 /**
3292  * Get the AVClass for AVCodecContext. It can be used in combination with
3293  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3294  *
3295  * @see av_opt_find().
3296  */
3297 const AVClass *avcodec_get_class(void);
3298 
3299 /**
3300  * Get the AVClass for AVFrame. It can be used in combination with
3301  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3302  *
3303  * @see av_opt_find().
3304  */
3305 const AVClass *avcodec_get_frame_class(void);
3306 
3307 /**
3308  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3309  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3310  *
3311  * @see av_opt_find().
3312  */
3314 
3315 /**
3316  * Copy the settings of the source AVCodecContext into the destination
3317  * AVCodecContext. The resulting destination codec context will be
3318  * unopened, i.e. you are required to call avcodec_open2() before you
3319  * can use this AVCodecContext to decode/encode video/audio data.
3320  *
3321  * @param dest target codec context, should be initialized with
3322  * avcodec_alloc_context3(NULL), but otherwise uninitialized
3323  * @param src source codec context
3324  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3325  */
3327 
3328 /**
3329  * Allocate an AVFrame and set its fields to default values. The resulting
3330  * struct must be freed using avcodec_free_frame().
3331  *
3332  * @return An AVFrame filled with default values or NULL on failure.
3333  * @see avcodec_get_frame_defaults
3334  */
3336 
3337 /**
3338  * Set the fields of the given AVFrame to default values.
3339  *
3340  * @param frame The AVFrame of which the fields should be set to default values.
3341  */
3343 
3344 /**
3345  * Free the frame and any dynamically allocated objects in it,
3346  * e.g. extended_data.
3347  *
3348  * @param frame frame to be freed. The pointer will be set to NULL.
3349  *
3350  * @warning this function does NOT free the data buffers themselves
3351  * (it does not know how, since they might have been allocated with
3352  * a custom get_buffer()).
3353  */
3355 
3356 #if FF_API_AVCODEC_OPEN
3357 /**
3358  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3359  * function the context has to be allocated.
3360  *
3361  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3362  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3363  * retrieving a codec.
3364  *
3365  * @warning This function is not thread safe!
3366  *
3367  * @code
3368  * avcodec_register_all();
3369  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3370  * if (!codec)
3371  * exit(1);
3372  *
3373  * context = avcodec_alloc_context3(codec);
3374  *
3375  * if (avcodec_open(context, codec) < 0)
3376  * exit(1);
3377  * @endcode
3378  *
3379  * @param avctx The context which will be set up to use the given codec.
3380  * @param codec The codec to use within the context.
3381  * @return zero on success, a negative value on error
3382  * @see avcodec_alloc_context3, avcodec_find_decoder, avcodec_find_encoder, avcodec_close
3383  *
3384  * @deprecated use avcodec_open2
3385  */
3387 int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
3388 #endif
3389 
3390 /**
3391  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3392  * function the context has to be allocated with avcodec_alloc_context3().
3393  *
3394  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3395  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3396  * retrieving a codec.
3397  *
3398  * @warning This function is not thread safe!
3399  *
3400  * @code
3401  * avcodec_register_all();
3402  * av_dict_set(&opts, "b", "2.5M", 0);
3403  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3404  * if (!codec)
3405  * exit(1);
3406  *
3407  * context = avcodec_alloc_context3(codec);
3408  *
3409  * if (avcodec_open2(context, codec, opts) < 0)
3410  * exit(1);
3411  * @endcode
3412  *
3413  * @param avctx The context to initialize.
3414  * @param codec The codec to open this context for. If a non-NULL codec has been
3415  * previously passed to avcodec_alloc_context3() or
3416  * avcodec_get_context_defaults3() for this context, then this
3417  * parameter MUST be either NULL or equal to the previously passed
3418  * codec.
3419  * @param options A dictionary filled with AVCodecContext and codec-private options.
3420  * On return this object will be filled with options that were not found.
3421  *
3422  * @return zero on success, a negative value on error
3423  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3424  * av_dict_set(), av_opt_find().
3425  */
3426 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3427 
3428 /**
3429  * Close a given AVCodecContext and free all the data associated with it
3430  * (but not the AVCodecContext itself).
3431  *
3432  * Calling this function on an AVCodecContext that hasn't been opened will free
3433  * the codec-specific data allocated in avcodec_alloc_context3() /
3434  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3435  * do nothing.
3436  */
3437 int avcodec_close(AVCodecContext *avctx);
3438 
3439 /**
3440  * Free all allocated data in the given subtitle struct.
3441  *
3442  * @param sub AVSubtitle to free.
3443  */
3444 void avsubtitle_free(AVSubtitle *sub);
3445 
3446 /**
3447  * @}
3448  */
3449 
3450 /**
3451  * @addtogroup lavc_packet
3452  * @{
3453  */
3454 
3455 #if FF_API_DESTRUCT_PACKET
3456 /**
3457  * Default packet destructor.
3458  * @deprecated use the AVBuffer API instead
3459  */
3461 void av_destruct_packet(AVPacket *pkt);
3462 #endif
3463 
3464 /**
3465  * Initialize optional fields of a packet with default values.
3466  *
3467  * Note, this does not touch the data and size members, which have to be
3468  * initialized separately.
3469  *
3470  * @param pkt packet
3471  */
3472 void av_init_packet(AVPacket *pkt);
3473 
3474 /**
3475  * Allocate the payload of a packet and initialize its fields with
3476  * default values.
3477  *
3478  * @param pkt packet
3479  * @param size wanted payload size
3480  * @return 0 if OK, AVERROR_xxx otherwise
3481  */
3482 int av_new_packet(AVPacket *pkt, int size);
3483 
3484 /**
3485  * Reduce packet size, correctly zeroing padding
3486  *
3487  * @param pkt packet
3488  * @param size new size
3489  */
3490 void av_shrink_packet(AVPacket *pkt, int size);
3491 
3492 /**
3493  * Increase packet size, correctly zeroing padding
3494  *
3495  * @param pkt packet
3496  * @param grow_by number of bytes by which to increase the size of the packet
3497  */
3498 int av_grow_packet(AVPacket *pkt, int grow_by);
3499 
3500 /**
3501  * Initialize a reference-counted packet from av_malloc()ed data.
3502  *
3503  * @param pkt packet to be initialized. This function will set the data, size,
3504  * buf and destruct fields, all others are left untouched.
3505  * @param data Data allocated by av_malloc() to be used as packet data. If this
3506  * function returns successfully, the data is owned by the underlying AVBuffer.
3507  * The caller may not access the data through other means.
3508  * @param size size of data in bytes, without the padding. I.e. the full buffer
3509  * size is assumed to be size + FF_INPUT_BUFFER_PADDING_SIZE.
3510  *
3511  * @return 0 on success, a negative AVERROR on error
3512  */
3514 
3515 /**
3516  * @warning This is a hack - the packet memory allocation stuff is broken. The
3517  * packet is allocated if it was not really allocated.
3518  */
3519 int av_dup_packet(AVPacket *pkt);
3520 
3521 /**
3522  * Copy packet, including contents
3523  *
3524  * @return 0 on success, negative AVERROR on fail
3525  */
3526 int av_copy_packet(AVPacket *dst, AVPacket *src);
3527 
3528 /**
3529  * Copy packet side data
3530  *
3531  * @return 0 on success, negative AVERROR on fail
3532  */
3534 
3535 /**
3536  * Free a packet.
3537  *
3538  * @param pkt packet to free
3539  */
3540 void av_free_packet(AVPacket *pkt);
3541 
3542 /**
3543  * Allocate new information of a packet.
3544  *
3545  * @param pkt packet
3546  * @param type side information type
3547  * @param size side information size
3548  * @return pointer to fresh allocated data or NULL otherwise
3549  */
3551  int size);
3552 
3553 /**
3554  * Shrink the already allocated side data buffer
3555  *
3556  * @param pkt packet
3557  * @param type side information type
3558  * @param size new side information size
3559  * @return 0 on success, < 0 on failure
3560  */
3562  int size);
3563 
3564 /**
3565  * Get side information from packet.
3566  *
3567  * @param pkt packet
3568  * @param type desired side information type
3569  * @param size pointer for side information size to store (optional)
3570  * @return pointer to data if present or NULL otherwise
3571  */
3573  int *size);
3574 
3576 
3578 
3579 
3580 /**
3581  * Convenience function to free all the side data stored.
3582  * All the other fields stay untouched.
3583  *
3584  * @param pkt packet
3585  */
3587 
3588 /**
3589  * Setup a new reference to the data described by a given packet
3590  *
3591  * If src is reference-counted, setup dst as a new reference to the
3592  * buffer in src. Otherwise allocate a new buffer in dst and copy the
3593  * data from src into it.
3594  *
3595  * All the other fields are copied from src.
3596  *
3597  * @see av_packet_unref
3598  *
3599  * @param dst Destination packet
3600  * @param src Source packet
3601  *
3602  * @return 0 on success, a negative AVERROR on error.
3603  */
3604 int av_packet_ref(AVPacket *dst, AVPacket *src);
3605 
3606 /**
3607  * Wipe the packet.
3608  *
3609  * Unreference the buffer referenced by the packet and reset the
3610  * remaining packet fields to their default values.
3611  *
3612  * @param pkt The packet to be unreferenced.
3613  */
3615 
3616 /**
3617  * Move every field in src to dst and reset src.
3618  *
3619  * @see av_packet_unref
3620  *
3621  * @param src Source packet, will be reset
3622  * @param dst Destination packet
3623  */
3625 
3626 /**
3627  * Copy only "properties" fields from src to dst.
3628  *
3629  * Properties for the purpose of this function are all the fields
3630  * beside those related to the packet data (buf, data, size)
3631  *
3632  * @param dst Destination packet
3633  * @param src Source packet
3634  *
3635  * @return 0 on success AVERROR on failure.
3636  *
3637  */
3638 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
3639 
3640 /**
3641  * @}
3642  */
3643 
3644 /**
3645  * @addtogroup lavc_decoding
3646  * @{
3647  */
3648 
3649 /**
3650  * Find a registered decoder with a matching codec ID.
3651  *
3652  * @param id AVCodecID of the requested decoder
3653  * @return A decoder if one was found, NULL otherwise.
3654  */
3656 
3657 /**
3658  * Find a registered decoder with the specified name.
3659  *
3660  * @param name name of the requested decoder
3661  * @return A decoder if one was found, NULL otherwise.
3662  */
3664 
3665 #if FF_API_GET_BUFFER
3666 attribute_deprecated int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
3667 attribute_deprecated void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
3668 attribute_deprecated int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
3669 #endif
3670 
3671 /**
3672  * The default callback for AVCodecContext.get_buffer2(). It is made public so
3673  * it can be called by custom get_buffer2() implementations for decoders without
3674  * CODEC_CAP_DR1 set.
3675  */
3677 
3678 /**
3679  * Return the amount of padding in pixels which the get_buffer callback must
3680  * provide around the edge of the image for codecs which do not have the
3681  * CODEC_FLAG_EMU_EDGE flag.
3682  *
3683  * @return Required padding in pixels.
3684  */
3685 unsigned avcodec_get_edge_width(void);
3686 
3687 /**
3688  * Modify width and height values so that they will result in a memory
3689  * buffer that is acceptable for the codec if you do not use any horizontal
3690  * padding.
3691  *
3692  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3693  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3694  * according to avcodec_get_edge_width() before.
3695  */
3697 
3698 /**
3699  * Modify width and height values so that they will result in a memory
3700  * buffer that is acceptable for the codec if you also ensure that all
3701  * line sizes are a multiple of the respective linesize_align[i].
3702  *
3703  * May only be used if a codec with CODEC_CAP_DR1 has been opened.
3704  * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
3705  * according to avcodec_get_edge_width() before.
3706  */
3708  int linesize_align[AV_NUM_DATA_POINTERS]);
3709 
3710 /**
3711  * Converts AVChromaLocation to swscale x/y chroma position.
3712  *
3713  * The positions represent the chroma (0,0) position in a coordinates system
3714  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3715  *
3716  * @param xpos horizontal chroma sample position
3717  * @param ypos vertical chroma sample position
3718  */
3719 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
3720 
3721 /**
3722  * Converts swscale x/y chroma position to AVChromaLocation.
3723  *
3724  * The positions represent the chroma (0,0) position in a coordinates system
3725  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
3726  *
3727  * @param xpos horizontal chroma sample position
3728  * @param ypos vertical chroma sample position
3729  */
3730 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
3731 
3732 #if FF_API_OLD_DECODE_AUDIO
3733 /**
3734  * Wrapper function which calls avcodec_decode_audio4.
3735  *
3736  * @deprecated Use avcodec_decode_audio4 instead.
3737  *
3738  * Decode the audio frame of size avpkt->size from avpkt->data into samples.
3739  * Some decoders may support multiple frames in a single AVPacket, such
3740  * decoders would then just decode the first frame. In this case,
3741  * avcodec_decode_audio3 has to be called again with an AVPacket that contains
3742  * the remaining data in order to decode the second frame etc.
3743  * If no frame
3744  * could be outputted, frame_size_ptr is zero. Otherwise, it is the
3745  * decompressed frame size in bytes.
3746  *
3747  * @warning You must set frame_size_ptr to the allocated size of the
3748  * output buffer before calling avcodec_decode_audio3().
3749  *
3750  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3751  * the actual read bytes because some optimized bitstream readers read 32 or 64
3752  * bits at once and could read over the end.
3753  *
3754  * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
3755  * no overreading happens for damaged MPEG streams.
3756  *
3757  * @warning You must not provide a custom get_buffer() when using
3758  * avcodec_decode_audio3(). Doing so will override it with
3759  * avcodec_default_get_buffer. Use avcodec_decode_audio4() instead,
3760  * which does allow the application to provide a custom get_buffer().
3761  *
3762  * @note You might have to align the input buffer avpkt->data and output buffer
3763  * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
3764  * necessary at all, on others it won't work at all if not aligned and on others
3765  * it will work but it will have an impact on performance.
3766  *
3767  * In practice, avpkt->data should have 4 byte alignment at minimum and
3768  * samples should be 16 byte aligned unless the CPU doesn't need it
3769  * (AltiVec and SSE do).
3770  *
3771  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3772  * between input and output, these need to be fed with avpkt->data=NULL,
3773  * avpkt->size=0 at the end to return the remaining frames.
3774  *
3775  * @param avctx the codec context
3776  * @param[out] samples the output buffer, sample type in avctx->sample_fmt
3777  * If the sample format is planar, each channel plane will
3778  * be the same size, with no padding between channels.
3779  * @param[in,out] frame_size_ptr the output buffer size in bytes
3780  * @param[in] avpkt The input AVPacket containing the input buffer.
3781  * You can create such packet with av_init_packet() and by then setting
3782  * data and size, some decoders might in addition need other fields.
3783  * All decoders are designed to use the least fields possible though.
3784  * @return On error a negative value is returned, otherwise the number of bytes
3785  * used or zero if no frame data was decompressed (used) from the input AVPacket.
3786  */
3787 attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
3788  int *frame_size_ptr,
3789  AVPacket *avpkt);
3790 #endif
3791 
3792 /**
3793  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
3794  *
3795  * Some decoders may support multiple frames in a single AVPacket. Such
3796  * decoders would then just decode the first frame and the return value would be
3797  * less than the packet size. In this case, avcodec_decode_audio4 has to be
3798  * called again with an AVPacket containing the remaining data in order to
3799  * decode the second frame, etc... Even if no frames are returned, the packet
3800  * needs to be fed to the decoder with remaining data until it is completely
3801  * consumed or an error occurs.
3802  *
3803  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
3804  * and output. This means that for some packets they will not immediately
3805  * produce decoded output and need to be flushed at the end of decoding to get
3806  * all the decoded data. Flushing is done by calling this function with packets
3807  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
3808  * returning samples. It is safe to flush even those decoders that are not
3809  * marked with CODEC_CAP_DELAY, then no samples will be returned.
3810  *
3811  * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
3812  * larger than the actual read bytes because some optimized bitstream
3813  * readers read 32 or 64 bits at once and could read over the end.
3814  *
3815  * @param avctx the codec context
3816  * @param[out] frame The AVFrame in which to store decoded audio samples.
3817  * The decoder will allocate a buffer for the decoded frame by
3818  * calling the AVCodecContext.get_buffer2() callback.
3819  * When AVCodecContext.refcounted_frames is set to 1, the frame is
3820  * reference counted and the returned reference belongs to the
3821  * caller. The caller must release the frame using av_frame_unref()
3822  * when the frame is no longer needed. The caller may safely write
3823  * to the frame if av_frame_is_writable() returns 1.
3824  * When AVCodecContext.refcounted_frames is set to 0, the returned
3825  * reference belongs to the decoder and is valid only until the
3826  * next call to this function or until closing or flushing the
3827  * decoder. The caller may not write to it.
3828  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
3829  * non-zero. Note that this field being set to zero
3830  * does not mean that an error has occurred. For
3831  * decoders with CODEC_CAP_DELAY set, no given decode
3832  * call is guaranteed to produce a frame.
3833  * @param[in] avpkt The input AVPacket containing the input buffer.
3834  * At least avpkt->data and avpkt->size should be set. Some
3835  * decoders might also require additional fields to be set.
3836  * @return A negative error code is returned if an error occurred during
3837  * decoding, otherwise the number of bytes consumed from the input
3838  * AVPacket is returned.
3839  */
3841  int *got_frame_ptr, const AVPacket *avpkt);
3842 
3843 /**
3844  * Decode the video frame of size avpkt->size from avpkt->data into picture.
3845  * Some decoders may support multiple frames in a single AVPacket, such
3846  * decoders would then just decode the first frame.
3847  *
3848  * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
3849  * the actual read bytes because some optimized bitstream readers read 32 or 64
3850  * bits at once and could read over the end.
3851  *
3852  * @warning The end of the input buffer buf should be set to 0 to ensure that
3853  * no overreading happens for damaged MPEG streams.
3854  *
3855  * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
3856  * between input and output, these need to be fed with avpkt->data=NULL,
3857  * avpkt->size=0 at the end to return the remaining frames.
3858  *
3859  * @param avctx the codec context
3860  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
3861  * Use av_frame_alloc() to get an AVFrame. The codec will
3862  * allocate memory for the actual bitmap by calling the
3863  * AVCodecContext.get_buffer2() callback.
3864  * When AVCodecContext.refcounted_frames is set to 1, the frame is
3865  * reference counted and the returned reference belongs to the
3866  * caller. The caller must release the frame using av_frame_unref()
3867  * when the frame is no longer needed. The caller may safely write
3868  * to the frame if av_frame_is_writable() returns 1.
3869  * When AVCodecContext.refcounted_frames is set to 0, the returned
3870  * reference belongs to the decoder and is valid only until the
3871  * next call to this function or until closing or flushing the
3872  * decoder. The caller may not write to it.
3873  *
3874  * @param[in] avpkt The input AVPacket containing the input buffer.
3875  * You can create such packet with av_init_packet() and by then setting
3876  * data and size, some decoders might in addition need other fields like
3877  * flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
3878  * fields possible.
3879  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
3880  * @return On error a negative value is returned, otherwise the number of bytes
3881  * used or zero if no frame could be decompressed.
3882  */
3883 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
3884  int *got_picture_ptr,
3885  const AVPacket *avpkt);
3886 
3887 /**
3888  * Decode a subtitle message.
3889  * Return a negative value on error, otherwise return the number of bytes used.
3890  * If no subtitle could be decompressed, got_sub_ptr is zero.
3891  * Otherwise, the subtitle is stored in *sub.
3892  * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
3893  * simplicity, because the performance difference is expect to be negligible
3894  * and reusing a get_buffer written for video codecs would probably perform badly
3895  * due to a potentially very different allocation pattern.
3896  *
3897  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
3898  * and output. This means that for some packets they will not immediately
3899  * produce decoded output and need to be flushed at the end of decoding to get
3900  * all the decoded data. Flushing is done by calling this function with packets
3901  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
3902  * returning subtitles. It is safe to flush even those decoders that are not
3903  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
3904  *
3905  * @param avctx the codec context
3906  * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
3907  freed with avsubtitle_free if *got_sub_ptr is set.
3908  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
3909  * @param[in] avpkt The input AVPacket containing the input buffer.
3910  */
3912  int *got_sub_ptr,
3913  AVPacket *avpkt);
3914 
3915 /**
3916  * @defgroup lavc_parsing Frame parsing
3917  * @{
3918  */
3922  AV_PICTURE_STRUCTURE_TOP_FIELD, //< coded as top field
3923  AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
3924  AV_PICTURE_STRUCTURE_FRAME, //< coded as frame
3925 };
3927 typedef struct AVCodecParserContext {
3928  void *priv_data;
3930  int64_t frame_offset; /* offset of the current frame */
3931  int64_t cur_offset; /* current offset
3932  (incremented by each av_parser_parse()) */
3933  int64_t next_frame_offset; /* offset of the next frame */
3934  /* video info */
3935  int pict_type; /* XXX: Put it back in AVCodecContext. */
3936  /**
3937  * This field is used for proper frame duration computation in lavf.
3938  * It signals, how much longer the frame duration of the current frame
3939  * is compared to normal frame duration.
3940  *
3941  * frame_duration = (1 + repeat_pict) * time_base
3942  *
3943  * It is used by codecs like H.264 to display telecined material.
3944  */
3945  int repeat_pict; /* XXX: Put it back in AVCodecContext. */
3946  int64_t pts; /* pts of the current frame */
3947  int64_t dts; /* dts of the current frame */
3948 
3949  /* private data */
3950  int64_t last_pts;
3951  int64_t last_dts;
3952  int fetch_timestamp;
3954 #define AV_PARSER_PTS_NB 4
3960  int flags;
3961 #define PARSER_FLAG_COMPLETE_FRAMES 0x0001
3962 #define PARSER_FLAG_ONCE 0x0002
3963 /// Set if the parser has a valid file offset
3964 #define PARSER_FLAG_FETCHED_OFFSET 0x0004
3965 #define PARSER_FLAG_USE_CODEC_TS 0x1000
3967  int64_t offset; ///< byte offset from starting packet start
3969 
3970  /**
3971  * Set by parser to 1 for key frames and 0 for non-key frames.
3972  * It is initialized to -1, so if the parser doesn't set this flag,
3973  * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
3974  * will be used.
3975  */
3976  int key_frame;
3977 
3978  /**
3979  * Time difference in stream time base units from the pts of this
3980  * packet to the point at which the output from the decoder has converged
3981  * independent from the availability of previous frames. That is, the
3982  * frames are virtually identical no matter if decoding started from
3983  * the very first frame or from this keyframe.
3984  * Is AV_NOPTS_VALUE if unknown.
3985  * This field is not the display duration of the current frame.
3986  * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
3987  * set.
3988  *
3989  * The purpose of this field is to allow seeking in streams that have no
3990  * keyframes in the conventional sense. It corresponds to the
3991  * recovery point SEI in H.264 and match_time_delta in NUT. It is also
3992  * essential for some types of subtitle streams to ensure that all
3993  * subtitles are correctly displayed after seeking.
3994  */
3995  int64_t convergence_duration;
3996 
3997  // Timestamp generation support:
3998  /**
3999  * Synchronization point for start of timestamp generation.
4000  *
4001  * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4002  * (default).
4003  *
4004  * For example, this corresponds to presence of H.264 buffering period
4005  * SEI message.
4006  */
4007  int dts_sync_point;
4008 
4009  /**
4010  * Offset of the current timestamp against last timestamp sync point in
4011  * units of AVCodecContext.time_base.
4012  *
4013  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4014  * contain a valid timestamp offset.
4015  *
4016  * Note that the timestamp of sync point has usually a nonzero
4017  * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4018  * the next frame after timestamp sync point will be usually 1.
4019  *
4020  * For example, this corresponds to H.264 cpb_removal_delay.
4021  */
4022  int dts_ref_dts_delta;
4023 
4024  /**
4025  * Presentation delay of current frame in units of AVCodecContext.time_base.
4026  *
4027  * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4028  * contain valid non-negative timestamp delta (presentation time of a frame
4029  * must not lie in the past).
4030  *
4031  * This delay represents the difference between decoding and presentation
4032  * time of the frame.
4033  *
4034  * For example, this corresponds to H.264 dpb_output_delay.
4035  */
4036  int pts_dts_delta;
4037 
4038  /**
4039  * Position of the packet in file.
4040  *
4041  * Analogous to cur_frame_pts/dts
4042  */
4044 
4045  /**
4046  * Byte position of currently parsed frame in stream.
4047  */
4048  int64_t pos;
4049 
4050  /**
4051  * Previous frame byte position.
4052  */
4053  int64_t last_pos;
4054 
4055  /**
4056  * Duration of the current frame.
4057  * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4058  * For all other types, this is in units of AVCodecContext.time_base.
4059  */
4060  int duration;
4063 
4064  /**
4065  * Indicate whether a picture is coded as a frame, top field or bottom field.
4066  *
4067  * For example, H.264 field_pic_flag equal to 0 corresponds to
4068  * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4069  * equal to 1 and bottom_field_flag equal to 0 corresponds to
4070  * AV_PICTURE_STRUCTURE_TOP_FIELD.
4071  */
4073 
4074  /**
4075  * Picture number incremented in presentation or output order.
4076  * This field may be reinitialized at the first picture of a new sequence.
4077  *
4078  * For example, this corresponds to H.264 PicOrderCnt.
4079  */
4083 typedef struct AVCodecParser {
4084  int codec_ids[5]; /* several codec IDs are permitted */
4088  AVCodecContext *avctx,
4089  const uint8_t **poutbuf, int *poutbuf_size,
4090  const uint8_t *buf, int buf_size);
4092  int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4093  struct AVCodecParser *next;
4094 } AVCodecParser;
4095 
4097 
4100 
4101 /**
4102  * Parse a packet.
4103  *
4104  * @param s parser context.
4105  * @param avctx codec context.
4106  * @param poutbuf set to pointer to parsed buffer or NULL if not yet finished.
4107  * @param poutbuf_size set to size of parsed buffer or zero if not yet finished.
4108  * @param buf input buffer.
4109  * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output).
4110  * @param pts input presentation timestamp.
4111  * @param dts input decoding timestamp.
4112  * @param pos input byte position in stream.
4113  * @return the number of bytes of the input bitstream used.
4114  *
4115  * Example:
4116  * @code
4117  * while(in_len){
4118  * len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4119  * in_data, in_len,
4120  * pts, dts, pos);
4121  * in_data += len;
4122  * in_len -= len;
4123  *
4124  * if(size)
4125  * decode_frame(data, size);
4126  * }
4127  * @endcode
4128  */
4130  AVCodecContext *avctx,
4131  uint8_t **poutbuf, int *poutbuf_size,
4132  const uint8_t *buf, int buf_size,
4133  int64_t pts, int64_t dts,
4134  int64_t pos);
4135 
4136 /**
4137  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4138  * @deprecated use AVBitStreamFilter
4139  */
4141  AVCodecContext *avctx,
4142  uint8_t **poutbuf, int *poutbuf_size,
4143  const uint8_t *buf, int buf_size, int keyframe);
4145 
4146 /**
4147  * @}
4148  * @}
4149  */
4150 
4151 /**
4152  * @addtogroup lavc_encoding
4153  * @{
4154  */
4155 
4156 /**
4157  * Find a registered encoder with a matching codec ID.
4158  *
4159  * @param id AVCodecID of the requested encoder
4160  * @return An encoder if one was found, NULL otherwise.
4161  */
4163 
4164 /**
4165  * Find a registered encoder with the specified name.
4166  *
4167  * @param name name of the requested encoder
4168  * @return An encoder if one was found, NULL otherwise.
4169  */
4171 
4172 #if FF_API_OLD_ENCODE_AUDIO
4173 /**
4174  * Encode an audio frame from samples into buf.
4175  *
4176  * @deprecated Use avcodec_encode_audio2 instead.
4177  *
4178  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
4179  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
4180  * will know how much space is needed because it depends on the value passed
4181  * in buf_size as described below. In that case a lower value can be used.
4182  *
4183  * @param avctx the codec context
4184  * @param[out] buf the output buffer
4185  * @param[in] buf_size the output buffer size
4186  * @param[in] samples the input buffer containing the samples
4187  * The number of samples read from this buffer is frame_size*channels,
4188  * both of which are defined in avctx.
4189  * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
4190  * samples read from samples is equal to:
4191  * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
4192  * This also implies that av_get_bits_per_sample() must not return 0 for these
4193  * codecs.
4194  * @return On error a negative value is returned, on success zero or the number
4195  * of bytes used to encode the data read from the input buffer.
4196  */
4197 int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
4198  uint8_t *buf, int buf_size,
4199  const short *samples);
4200 #endif
4201 
4202 /**
4203  * Encode a frame of audio.
4204  *
4205  * Takes input samples from frame and writes the next output packet, if
4206  * available, to avpkt. The output packet does not necessarily contain data for
4207  * the most recent frame, as encoders can delay, split, and combine input frames
4208  * internally as needed.
4209  *
4210  * @param avctx codec context
4211  * @param avpkt output AVPacket.
4212  * The user can supply an output buffer by setting
4213  * avpkt->data and avpkt->size prior to calling the
4214  * function, but if the size of the user-provided data is not
4215  * large enough, encoding will fail. If avpkt->data and
4216  * avpkt->size are set, avpkt->destruct must also be set. All
4217  * other AVPacket fields will be reset by the encoder using
4218  * av_init_packet(). If avpkt->data is NULL, the encoder will
4219  * allocate it. The encoder will set avpkt->size to the size
4220  * of the output packet.
4221  *
4222  * If this function fails or produces no output, avpkt will be
4223  * freed using av_free_packet() (i.e. avpkt->destruct will be
4224  * called to free the user supplied buffer).
4225  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4226  * May be NULL when flushing an encoder that has the
4227  * CODEC_CAP_DELAY capability set.
4228  * If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4229  * can have any number of samples.
4230  * If it is not set, frame->nb_samples must be equal to
4231  * avctx->frame_size for all frames except the last.
4232  * The final frame may be smaller than avctx->frame_size.
4233  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4234  * output packet is non-empty, and to 0 if it is
4235  * empty. If the function returns an error, the
4236  * packet can be assumed to be invalid, and the
4237  * value of got_packet_ptr is undefined and should
4238  * not be used.
4239  * @return 0 on success, negative error code on failure
4240  */
4241 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4242  const AVFrame *frame, int *got_packet_ptr);
4243 
4244 #if FF_API_OLD_ENCODE_VIDEO
4245 /**
4246  * @deprecated use avcodec_encode_video2() instead.
4247  *
4248  * Encode a video frame from pict into buf.
4249  * The input picture should be
4250  * stored using a specific format, namely avctx.pix_fmt.
4251  *
4252  * @param avctx the codec context
4253  * @param[out] buf the output buffer for the bitstream of encoded frame
4254  * @param[in] buf_size the size of the output buffer in bytes
4255  * @param[in] pict the input picture to encode
4256  * @return On error a negative value is returned, on success zero or the number
4257  * of bytes used from the output buffer.
4258  */
4260 int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4261  const AVFrame *pict);
4262 #endif
4263 
4264 /**
4265  * Encode a frame of video.
4266  *
4267  * Takes input raw video data from frame and writes the next output packet, if
4268  * available, to avpkt. The output packet does not necessarily contain data for
4269  * the most recent frame, as encoders can delay and reorder input frames
4270  * internally as needed.
4271  *
4272  * @param avctx codec context
4273  * @param avpkt output AVPacket.
4274  * The user can supply an output buffer by setting
4275  * avpkt->data and avpkt->size prior to calling the
4276  * function, but if the size of the user-provided data is not
4277  * large enough, encoding will fail. All other AVPacket fields
4278  * will be reset by the encoder using av_init_packet(). If
4279  * avpkt->data is NULL, the encoder will allocate it.
4280  * The encoder will set avpkt->size to the size of the
4281  * output packet. The returned data (if any) belongs to the
4282  * caller, he is responsible for freeing it.
4283  *
4284  * If this function fails or produces no output, avpkt will be
4285  * freed using av_free_packet() (i.e. avpkt->destruct will be
4286  * called to free the user supplied buffer).
4287  * @param[in] frame AVFrame containing the raw video data to be encoded.
4288  * May be NULL when flushing an encoder that has the
4289  * CODEC_CAP_DELAY capability set.
4290  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4291  * output packet is non-empty, and to 0 if it is
4292  * empty. If the function returns an error, the
4293  * packet can be assumed to be invalid, and the
4294  * value of got_packet_ptr is undefined and should
4295  * not be used.
4296  * @return 0 on success, negative error code on failure
4297  */
4298 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4299  const AVFrame *frame, int *got_packet_ptr);
4300 
4301 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4302  const AVSubtitle *sub);
4303 
4304 
4305 /**
4306  * @}
4307  */
4308 
4309 #if FF_API_AVCODEC_RESAMPLE
4310 /**
4311  * @defgroup lavc_resample Audio resampling
4312  * @ingroup libavc
4313  * @deprecated use libswresample instead
4314  *
4315  * @{
4316  */
4317 struct ReSampleContext;
4318 struct AVResampleContext;
4319 
4320 typedef struct ReSampleContext ReSampleContext;
4321 
4322 /**
4323  * Initialize audio resampling context.
4324  *
4325  * @param output_channels number of output channels
4326  * @param input_channels number of input channels
4327  * @param output_rate output sample rate
4328  * @param input_rate input sample rate
4329  * @param sample_fmt_out requested output sample format
4330  * @param sample_fmt_in input sample format
4331  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff frequency
4332  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4333  * @param linear if 1 then the used FIR filter will be linearly interpolated
4334  between the 2 closest, if 0 the closest will be used
4335  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4336  * @return allocated ReSampleContext, NULL if error occurred
4337  */
4339 ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
4340  int output_rate, int input_rate,
4341  enum AVSampleFormat sample_fmt_out,
4342  enum AVSampleFormat sample_fmt_in,
4343  int filter_length, int log2_phase_count,
4344  int linear, double cutoff);
4345 
4347 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4348 
4349 /**
4350  * Free resample context.
4351  *
4352  * @param s a non-NULL pointer to a resample context previously
4353  * created with av_audio_resample_init()
4354  */
4356 void audio_resample_close(ReSampleContext *s);
4357 
4358 
4359 /**
4360  * Initialize an audio resampler.
4361  * Note, if either rate is not an integer then simply scale both rates up so they are.
4362  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4363  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4364  * @param linear If 1 then the used FIR filter will be linearly interpolated
4365  between the 2 closest, if 0 the closest will be used
4366  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4367  */
4369 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4370 
4371 /**
4372  * Resample an array of samples using a previously configured context.
4373  * @param src an array of unconsumed samples
4374  * @param consumed the number of samples of src which have been consumed are returned here
4375  * @param src_size the number of unconsumed samples available
4376  * @param dst_size the amount of space in samples available in dst
4377  * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
4378  * @return the number of samples written in dst or -1 if an error occurred
4379  */
4381 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4382 
4383 
4384 /**
4385  * Compensate samplerate/timestamp drift. The compensation is done by changing
4386  * the resampler parameters, so no audible clicks or similar distortions occur
4387  * @param compensation_distance distance in output samples over which the compensation should be performed
4388  * @param sample_delta number of output samples which should be output less
4389  *
4390  * example: av_resample_compensate(c, 10, 500)
4391  * here instead of 510 samples only 500 samples would be output
4392  *
4393  * note, due to rounding the actual compensation might be slightly different,
4394  * especially if the compensation_distance is large and the in_rate used during init is small
4395  */
4397 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4399 void av_resample_close(struct AVResampleContext *c);
4400 
4401 /**
4402  * @}
4403  */
4404 #endif
4405 
4406 /**
4407  * @addtogroup lavc_picture
4408  * @{
4409  */
4410 
4411 /**
4412  * Allocate memory for the pixels of a picture and setup the AVPicture
4413  * fields for it.
4414  *
4415  * Call avpicture_free() to free it.
4416  *
4417  * @param picture the picture structure to be filled in
4418  * @param pix_fmt the pixel format of the picture
4419  * @param width the width of the picture
4420  * @param height the height of the picture
4421  * @return zero if successful, a negative error code otherwise
4422  *
4423  * @see av_image_alloc(), avpicture_fill()
4424  */
4425 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4426 
4427 /**
4428  * Free a picture previously allocated by avpicture_alloc().
4429  * The data buffer used by the AVPicture is freed, but the AVPicture structure
4430  * itself is not.
4431  *
4432  * @param picture the AVPicture to be freed
4433  */
4434 void avpicture_free(AVPicture *picture);
4435 
4436 /**
4437  * Setup the picture fields based on the specified image parameters
4438  * and the provided image data buffer.
4439  *
4440  * The picture fields are filled in by using the image data buffer
4441  * pointed to by ptr.
4442  *
4443  * If ptr is NULL, the function will fill only the picture linesize
4444  * array and return the required size for the image buffer.
4445  *
4446  * To allocate an image buffer and fill the picture data in one call,
4447  * use avpicture_alloc().
4448  *
4449  * @param picture the picture to be filled in
4450  * @param ptr buffer where the image data is stored, or NULL
4451  * @param pix_fmt the pixel format of the image
4452  * @param width the width of the image in pixels
4453  * @param height the height of the image in pixels
4454  * @return the size in bytes required for src, a negative error code
4455  * in case of failure
4456  *
4457  * @see av_image_fill_arrays()
4458  */
4459 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4460  enum AVPixelFormat pix_fmt, int width, int height);
4461 
4462 /**
4463  * Copy pixel data from an AVPicture into a buffer.
4464  *
4465  * avpicture_get_size() can be used to compute the required size for
4466  * the buffer to fill.
4467  *
4468  * @param src source picture with filled data
4469  * @param pix_fmt picture pixel format
4470  * @param width picture width
4471  * @param height picture height
4472  * @param dest destination buffer
4473  * @param dest_size destination buffer size in bytes
4474  * @return the number of bytes written to dest, or a negative value
4475  * (error code) on error, for example if the destination buffer is not
4476  * big enough
4477  *
4478  * @see av_image_copy_to_buffer()
4479  */
4481  int width, int height,
4482  unsigned char *dest, int dest_size);
4483 
4484 /**
4485  * Calculate the size in bytes that a picture of the given width and height
4486  * would occupy if stored in the given picture format.
4487  *
4488  * @param pix_fmt picture pixel format
4489  * @param width picture width
4490  * @param height picture height
4491  * @return the computed picture buffer size or a negative error code
4492  * in case of error
4493  *
4494  * @see av_image_get_buffer_size().
4495  */
4497 
4498 #if FF_API_DEINTERLACE
4499 /**
4500  * deinterlace - if not supported return -1
4501  *
4502  * @deprecated - use yadif (in libavfilter) instead
4503  */
4505 int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
4506  enum AVPixelFormat pix_fmt, int width, int height);
4507 #endif
4508 /**
4509  * Copy image src to dst. Wraps av_image_copy().
4510  */
4511 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4512  enum AVPixelFormat pix_fmt, int width, int height);
4513 
4514 /**
4515  * Crop image top and left side.
4516  */
4517 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4518  enum AVPixelFormat pix_fmt, int top_band, int left_band);
4519 
4520 /**
4521  * Pad image.
4522  */
4523 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4524  int padtop, int padbottom, int padleft, int padright, int *color);
4525 
4526 /**
4527  * @}
4528  */
4529 
4530 /**
4531  * @defgroup lavc_misc Utility functions
4532  * @ingroup libavc
4533  *
4534  * Miscellaneous utility functions related to both encoding and decoding
4535  * (or neither).
4536  * @{
4537  */
4538 
4539 /**
4540  * @defgroup lavc_misc_pixfmt Pixel formats
4541  *
4542  * Functions for working with pixel formats.
4543  * @{
4544  */
4545 
4546 /**
4547  * Utility function to access log2_chroma_w log2_chroma_h from
4548  * the pixel format AVPixFmtDescriptor.
4549  *
4550  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4551  * for one that returns a failure code and continues in case of invalid
4552  * pix_fmts.
4553  *
4554  * @param[in] pix_fmt the pixel format
4555  * @param[out] h_shift store log2_chroma_w
4556  * @param[out] v_shift store log2_chroma_h
4557  *
4558  * @see av_pix_fmt_get_chroma_sub_sample
4559  */
4560 
4561 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4562 
4563 /**
4564  * Return a value representing the fourCC code associated to the
4565  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4566  * found.
4567  */
4570 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
4571 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
4572 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
4573 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
4574 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
4575 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
4576 
4577 /**
4578  * Compute what kind of losses will occur when converting from one specific
4579  * pixel format to another.
4580  * When converting from one pixel format to another, information loss may occur.
4581  * For example, when converting from RGB24 to GRAY, the color information will
4582  * be lost. Similarly, other losses occur when converting from some formats to
4583  * other formats. These losses can involve loss of chroma, but also loss of
4584  * resolution, loss of color depth, loss due to the color space conversion, loss
4585  * of the alpha bits or loss due to color quantization.
4586  * avcodec_get_fix_fmt_loss() informs you about the various types of losses
4587  * which will occur when converting from one pixel format to another.
4588  *
4589  * @param[in] dst_pix_fmt destination pixel format
4590  * @param[in] src_pix_fmt source pixel format
4591  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4592  * @return Combination of flags informing you what kind of losses will occur
4593  * (maximum loss for an invalid dst_pix_fmt).
4594  */
4595 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4596  int has_alpha);
4597 
4598 /**
4599  * Find the best pixel format to convert to given a certain source pixel
4600  * format. When converting from one pixel format to another, information loss
4601  * may occur. For example, when converting from RGB24 to GRAY, the color
4602  * information will be lost. Similarly, other losses occur when converting from
4603  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4604  * the given pixel formats should be used to suffer the least amount of loss.
4605  * The pixel formats from which it chooses one, are determined by the
4606  * pix_fmt_list parameter.
4607  *
4608  *
4609  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
4610  * @param[in] src_pix_fmt source pixel format
4611  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4612  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
4613  * @return The best pixel format to convert to or -1 if none was found.
4614  */
4615 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
4616  enum AVPixelFormat src_pix_fmt,
4617  int has_alpha, int *loss_ptr);
4618 
4619 /**
4620  * Find the best pixel format to convert to given a certain source pixel
4621  * format and a selection of two destination pixel formats. When converting from
4622  * one pixel format to another, information loss may occur. For example, when converting
4623  * from RGB24 to GRAY, the color information will be lost. Similarly, other losses occur when
4624  * converting from some formats to other formats. avcodec_find_best_pix_fmt_of_2() selects which of
4625  * the given pixel formats should be used to suffer the least amount of loss.
4626  *
4627  * If one of the destination formats is AV_PIX_FMT_NONE the other pixel format (if valid) will be
4628  * returned.
4629  *
4630  * @code
4631  * src_pix_fmt = AV_PIX_FMT_YUV420P;
4632  * dst_pix_fmt1= AV_PIX_FMT_RGB24;
4633  * dst_pix_fmt2= AV_PIX_FMT_GRAY8;
4634  * dst_pix_fmt3= AV_PIX_FMT_RGB8;
4635  * loss= FF_LOSS_CHROMA; // don't care about chroma loss, so chroma loss will be ignored.
4636  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt1, dst_pix_fmt2, src_pix_fmt, alpha, &loss);
4637  * dst_pix_fmt = avcodec_find_best_pix_fmt_of_2(dst_pix_fmt, dst_pix_fmt3, src_pix_fmt, alpha, &loss);
4638  * @endcode
4639  *
4640  * @param[in] dst_pix_fmt1 One of the two destination pixel formats to choose from
4641  * @param[in] dst_pix_fmt2 The other of the two destination pixel formats to choose from
4642  * @param[in] src_pix_fmt Source pixel format
4643  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
4644  * @param[in, out] loss_ptr Combination of loss flags. In: selects which of the losses to ignore, i.e.
4645  * NULL or value of zero means we care about all losses. Out: the loss
4646  * that occurs when converting from src to selected dst pixel format.
4647  * @return The best pixel format to convert to or -1 if none was found.
4648  */
4649 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4650  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4651 
4653 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
4654 enum AVPixelFormat avcodec_find_best_pix_fmt2(const enum AVPixelFormat *pix_fmt_list,
4655  enum AVPixelFormat src_pix_fmt,
4656  int has_alpha, int *loss_ptr);
4657 #else
4658 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
4659  enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
4660 #endif
4661 
4662 
4664 
4665 /**
4666  * @}
4667  */
4668 
4670 
4671 /**
4672  * Put a string representing the codec tag codec_tag in buf.
4673  *
4674  * @param buf_size size in bytes of buf
4675  * @return the length of the string that would have been generated if
4676  * enough space had been available, excluding the trailing null
4677  */
4678 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
4679 
4680 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
4681 
4682 /**
4683  * Return a name for the specified profile, if available.
4684  *
4685  * @param codec the codec that is searched for the given profile
4686  * @param profile the profile value for which a name is requested
4687  * @return A name for the profile if found, NULL otherwise.
4688  */
4689 const char *av_get_profile_name(const AVCodec *codec, int profile);
4690 
4691 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
4692 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
4693 //FIXME func typedef
4694 
4695 /**
4696  * Fill AVFrame audio data and linesize pointers.
4697  *
4698  * The buffer buf must be a preallocated buffer with a size big enough
4699  * to contain the specified samples amount. The filled AVFrame data
4700  * pointers will point to this buffer.
4701  *
4702  * AVFrame extended_data channel pointers are allocated if necessary for
4703  * planar audio.
4704  *
4705  * @param frame the AVFrame
4706  * frame->nb_samples must be set prior to calling the
4707  * function. This function fills in frame->data,
4708  * frame->extended_data, frame->linesize[0].
4709  * @param nb_channels channel count
4710  * @param sample_fmt sample format
4711  * @param buf buffer to use for frame data
4712  * @param buf_size size of buffer
4713  * @param align plane size sample alignment (0 = default)
4714  * @return >=0 on success, negative error code on failure
4715  * @todo return the size in bytes required to store the samples in
4716  * case of success, at the next libavutil bump
4717  */
4719  enum AVSampleFormat sample_fmt, const uint8_t *buf,
4720  int buf_size, int align);
4721 
4722 /**
4723  * Reset the internal decoder state / flush internal buffers. Should be called
4724  * e.g. when seeking or when switching to a different stream.
4725  *
4726  * @note when refcounted frames are not used (i.e. avctx->refcounted_frames is 0),
4727  * this invalidates the frames previously returned from the decoder. When
4728  * refcounted frames are used, the decoder just releases any references it might
4729  * keep internally, but the caller's reference remains valid.
4730  */
4732 
4733 /**
4734  * Return codec bits per sample.
4735  *
4736  * @param[in] codec_id the codec
4737  * @return Number of bits per sample or zero if unknown for the given codec.
4738  */
4740 
4741 /**
4742  * Return the PCM codec associated with a sample format.
4743  * @param be endianness, 0 for little, 1 for big,
4744  * -1 (or anything else) for native
4745  * @return AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
4746  */
4747 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
4748 
4749 /**
4750  * Return codec bits per sample.
4751  * Only return non-zero if the bits per sample is exactly correct, not an
4752  * approximation.
4753  *
4754  * @param[in] codec_id the codec
4755  * @return Number of bits per sample or zero if unknown for the given codec.
4756  */
4758 
4759 /**
4760  * Return audio frame duration.
4761  *
4762  * @param avctx codec context
4763  * @param frame_bytes size of the frame, or 0 if unknown
4764  * @return frame duration, in samples, if known. 0 if not able to
4765  * determine.
4766  */
4767 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
4768 
4771  void *priv_data;
4776 
4778 typedef struct AVBitStreamFilter {
4779  const char *name;
4781  int (*filter)(AVBitStreamFilterContext *bsfc,
4782  AVCodecContext *avctx, const char *args,
4783  uint8_t **poutbuf, int *poutbuf_size,
4784  const uint8_t *buf, int buf_size, int keyframe);
4786  struct AVBitStreamFilter *next;
4788 
4789 /**
4790  * Register a bitstream filter.
4791  *
4792  * The filter will be accessible to the application code through
4793  * av_bitstream_filter_next() or can be directly initialized with
4794  * av_bitstream_filter_init().
4795  *
4796  * @see avcodec_register_all()
4797  */
4799 
4800 /**
4801  * Create and initialize a bitstream filter context given a bitstream
4802  * filter name.
4803  *
4804  * The returned context must be freed with av_bitstream_filter_close().
4805  *
4806  * @param name the name of the bitstream filter
4807  * @return a bitstream filter context if a matching filter was found
4808  * and successfully initialized, NULL otherwise
4809  */
4811 
4812 /**
4813  * Filter bitstream.
4814  *
4815  * This function filters the buffer buf with size buf_size, and places the
4816  * filtered buffer in the buffer pointed to by poutbuf.
4817  *
4818  * The output buffer must be freed by the caller.
4819  *
4820  * @param bsfc bitstream filter context created by av_bitstream_filter_init()
4821  * @param avctx AVCodecContext accessed by the filter, may be NULL.
4822  * If specified, this must point to the encoder context of the
4823  * output stream the packet is sent to.
4824  * @param args arguments which specify the filter configuration, may be NULL
4825  * @param poutbuf pointer which is updated to point to the filtered buffer
4826  * @param poutbuf_size pointer which is updated to the filtered buffer size in bytes
4827  * @param buf buffer containing the data to filter
4828  * @param buf_size size in bytes of buf
4829  * @param keyframe set to non-zero if the buffer to filter corresponds to a key-frame packet data
4830  * @return >= 0 in case of success, or a negative error code in case of failure
4831  *
4832  * If the return value is positive, an output buffer is allocated and
4833  * is availble in *poutbuf, and is distinct from the input buffer.
4834  *
4835  * If the return value is 0, the output buffer is not allocated and
4836  * should be considered identical to the input buffer, or in case
4837  * *poutbuf was set it points to the input buffer (not necessarily to
4838  * its starting address).
4839  */
4841  AVCodecContext *avctx, const char *args,
4842  uint8_t **poutbuf, int *poutbuf_size,
4843  const uint8_t *buf, int buf_size, int keyframe);
4844 
4845 /**
4846  * Release bitstream filter context.
4847  *
4848  * @param bsf the bitstream filter context created with
4849  * av_bitstream_filter_init(), can be NULL
4850  */
4852 
4853 /**
4854  * If f is NULL, return the first registered bitstream filter,
4855  * if f is non-NULL, return the next registered bitstream filter
4856  * after f, or NULL if f is the last one.
4857  *
4858  * This function can be used to iterate over all registered bitstream
4859  * filters.
4860  */
4862 
4863 /* memory */
4864 
4865 /**
4866  * Reallocate the given block if it is not large enough, otherwise do nothing.
4867  *
4868  * @see av_realloc
4869  */
4870 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
4871 
4872 /**
4873  * Allocate a buffer, reusing the given one if large enough.
4874  *
4875  * Contrary to av_fast_realloc the current buffer contents might not be
4876  * preserved and on error the old buffer is freed, thus no special
4877  * handling to avoid memleaks is necessary.
4878  *
4879  * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
4880  * @param size size of the buffer *ptr points to
4881  * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
4882  * *size 0 if an error occurred.
4883  */
4884 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
4885 
4886 /**
4887  * Same behaviour av_fast_malloc but the buffer has additional
4888  * FF_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
4889  *
4890  * In addition the whole buffer will initially and after resizes
4891  * be 0-initialized so that no uninitialized data will ever appear.
4892  */
4893 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
4894 
4895 /**
4896  * Same behaviour av_fast_padded_malloc except that buffer will always
4897  * be 0-initialized after call.
4898  */
4899 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
4900 
4901 /**
4902  * Encode extradata length to a buffer. Used by xiph codecs.
4903  *
4904  * @param s buffer to write to; must be at least (v/255+1) bytes long
4905  * @param v size of extradata in bytes
4906  * @return number of bytes written to the buffer.
4907  */
4908 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
4909 
4910 #if FF_API_MISSING_SAMPLE
4911 /**
4912  * Log a generic warning message about a missing feature. This function is
4913  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4914  * only, and would normally not be used by applications.
4915  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4916  * a pointer to an AVClass struct
4917  * @param[in] feature string containing the name of the missing feature
4918  * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
4919  * If want_sample is non-zero, additional verbage will be added to the log
4920  * message which tells the user how to report samples to the development
4921  * mailing list.
4922  * @deprecated Use avpriv_report_missing_feature() instead.
4923  */
4925 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
4926 
4927 /**
4928  * Log a generic warning message asking for a sample. This function is
4929  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
4930  * only, and would normally not be used by applications.
4931  * @param[in] avc a pointer to an arbitrary struct of which the first field is
4932  * a pointer to an AVClass struct
4933  * @param[in] msg string containing an optional message, or NULL if no message
4934  * @deprecated Use avpriv_request_sample() instead.
4935  */
4937 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
4938 #endif /* FF_API_MISSING_SAMPLE */
4939 
4940 /**
4941  * Register the hardware accelerator hwaccel.
4942  */
4943 void av_register_hwaccel(AVHWAccel *hwaccel);
4944 
4945 /**
4946  * If hwaccel is NULL, returns the first registered hardware accelerator,
4947  * if hwaccel is non-NULL, returns the next registered hardware accelerator
4948  * after hwaccel, or NULL if hwaccel is the last one.
4949  */
4951 
4952 
4953 /**
4954  * Lock operation used by lockmgr
4955  */
4956 enum AVLockOp {
4957  AV_LOCK_CREATE, ///< Create a mutex
4958  AV_LOCK_OBTAIN, ///< Lock the mutex
4959  AV_LOCK_RELEASE, ///< Unlock the mutex
4960  AV_LOCK_DESTROY, ///< Free mutex resources
4961 };
4962 
4963 /**
4964  * Register a user provided lock manager supporting the operations
4965  * specified by AVLockOp. mutex points to a (void *) where the
4966  * lockmgr should store/get a pointer to a user allocated mutex. It's
4967  * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
4968  *
4969  * @param cb User defined callback. Note: FFmpeg may invoke calls to this
4970  * callback during the call to av_lockmgr_register().
4971  * Thus, the application must be prepared to handle that.
4972  * If cb is set to NULL the lockmgr will be unregistered.
4973  * Also note that during unregistration the previously registered
4974  * lockmgr callback may also be invoked.
4975  */
4976 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
4977 
4978 /**
4979  * Get the type of the given codec.
4980  */
4982 
4983 /**
4984  * Get the name of a codec.
4985  * @return a static string identifying the codec; never NULL
4986  */
4987 const char *avcodec_get_name(enum AVCodecID id);
4988 
4989 /**
4990  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
4991  * with no corresponding avcodec_close()), 0 otherwise.
4992  */
4994 
4995 /**
4996  * @return a non-zero number if codec is an encoder, zero otherwise
4997  */
4998 int av_codec_is_encoder(const AVCodec *codec);
4999 
5000 /**
5001  * @return a non-zero number if codec is a decoder, zero otherwise
5002  */
5003 int av_codec_is_decoder(const AVCodec *codec);
5004 
5005 /**
5006  * @return descriptor for given codec ID or NULL if no descriptor exists.
5007  */
5009 
5010 /**
5011  * Iterate over all codec descriptors known to libavcodec.
5012  *
5013  * @param prev previous descriptor. NULL to get the first descriptor.
5014  *
5015  * @return next descriptor or NULL after the last descriptor
5016  */
5018 
5019 /**
5020  * @return codec descriptor with the given name or NULL if no such descriptor
5021  * exists.
5022  */