FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
frame.h
Go to the documentation of this file.
1 /*
2  *
3  * This file is part of FFmpeg.
4  *
5  * FFmpeg is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * FFmpeg is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with FFmpeg; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 /**
21  * @file
22  * @ingroup lavu_frame
23  * reference-counted frame API
24  */
25 
26 #ifndef AVUTIL_FRAME_H
27 #define AVUTIL_FRAME_H
28 
29 #include <stdint.h>
30 
31 #include "avutil.h"
32 #include "buffer.h"
33 #include "dict.h"
34 #include "rational.h"
35 #include "samplefmt.h"
36 #include "pixfmt.h"
37 #include "version.h"
38 
39 
40 /**
41  * @defgroup lavu_frame AVFrame
42  * @ingroup lavu_data
43  *
44  * @{
45  * AVFrame is an abstraction for reference-counted raw multimedia data.
46  */
47 
49  /**
50  * The data is the AVPanScan struct defined in libavcodec.
51  */
53  /**
54  * ATSC A53 Part 4 Closed Captions.
55  * A53 CC bitstream is stored as uint8_t in AVFrameSideData.data.
56  * The number of bytes of CC data is AVFrameSideData.size.
57  */
59  /**
60  * Stereoscopic 3d metadata.
61  * The data is the AVStereo3D struct defined in libavutil/stereo3d.h.
62  */
64  /**
65  * The data is the AVMatrixEncoding enum defined in libavutil/channel_layout.h.
66  */
68  /**
69  * Metadata relevant to a downmix procedure.
70  * The data is the AVDownmixInfo struct defined in libavutil/downmix_info.h.
71  */
73  /**
74  * ReplayGain information in the form of the AVReplayGain struct.
75  */
77  /**
78  * This side data contains a 3x3 transformation matrix describing an affine
79  * transformation that needs to be applied to the frame for correct
80  * presentation.
81  *
82  * See libavutil/display.h for a detailed description of the data.
83  */
85 };
86 
87 typedef struct AVFrameSideData {
90  int size;
93 
94 /**
95  * This structure describes decoded (raw) audio or video data.
96  *
97  * AVFrame must be allocated using av_frame_alloc(). Note that this only
98  * allocates the AVFrame itself, the buffers for the data must be managed
99  * through other means (see below).
100  * AVFrame must be freed with av_frame_free().
101  *
102  * AVFrame is typically allocated once and then reused multiple times to hold
103  * different data (e.g. a single AVFrame to hold frames received from a
104  * decoder). In such a case, av_frame_unref() will free any references held by
105  * the frame and reset it to its original clean state before it
106  * is reused again.
107  *
108  * The data described by an AVFrame is usually reference counted through the
109  * AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
110  * AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
111  * least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
112  * every single data plane must be contained in one of the buffers in
113  * AVFrame.buf or AVFrame.extended_buf.
114  * There may be a single buffer for all the data, or one separate buffer for
115  * each plane, or anything in between.
116  *
117  * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
118  * to the end with a minor bump.
119  * Similarly fields that are marked as to be only accessed by
120  * av_opt_ptr() can be reordered. This allows 2 forks to add fields
121  * without breaking compatibility with each other.
122  */
123 typedef struct AVFrame {
124 #define AV_NUM_DATA_POINTERS 8
125  /**
126  * pointer to the picture/channel planes.
127  * This might be different from the first allocated byte
128  *
129  * Some decoders access areas outside 0,0 - width,height, please
130  * see avcodec_align_dimensions2(). Some filters and swscale can read
131  * up to 16 bytes beyond the planes, if these filters are to be used,
132  * then 16 extra bytes must be allocated.
133  */
135 
136  /**
137  * For video, size in bytes of each picture line.
138  * For audio, size in bytes of each plane.
139  *
140  * For audio, only linesize[0] may be set. For planar audio, each channel
141  * plane must be the same size.
142  *
143  * For video the linesizes should be multiplies of the CPUs alignment
144  * preference, this is 16 or 32 for modern desktop CPUs.
145  * Some code requires such alignment other code can be slower without
146  * correct alignment, for yet other it makes no difference.
147  *
148  * @note The linesize may be larger than the size of usable data -- there
149  * may be extra padding present for performance reasons.
150  */
152 
153  /**
154  * pointers to the data planes/channels.
155  *
156  * For video, this should simply point to data[].
157  *
158  * For planar audio, each channel has a separate data pointer, and
159  * linesize[0] contains the size of each channel buffer.
160  * For packed audio, there is just one data pointer, and linesize[0]
161  * contains the total size of the buffer for all channels.
162  *
163  * Note: Both data and extended_data should always be set in a valid frame,
164  * but for planar audio with more channels that can fit in data,
165  * extended_data must be used in order to access all channels.
166  */
168 
169  /**
170  * width and height of the video frame
171  */
172  int width, height;
173 
174  /**
175  * number of audio samples (per channel) described by this frame
176  */
178 
179  /**
180  * format of the frame, -1 if unknown or unset
181  * Values correspond to enum AVPixelFormat for video frames,
182  * enum AVSampleFormat for audio)
183  */
184  int format;
185 
186  /**
187  * 1 -> keyframe, 0-> not
188  */
190 
191  /**
192  * Picture type of the frame.
193  */
195 
196 #if FF_API_AVFRAME_LAVC
199 #endif
200 
201  /**
202  * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
203  */
205 
206  /**
207  * Presentation timestamp in time_base units (time when frame should be shown to user).
208  */
209  int64_t pts;
210 
211  /**
212  * PTS copied from the AVPacket that was decoded to produce this frame.
213  */
214  int64_t pkt_pts;
215 
216  /**
217  * DTS copied from the AVPacket that triggered returning this frame. (if frame threading isn't used)
218  * This is also the Presentation time of this AVFrame calculated from
219  * only AVPacket.dts values without pts values.
220  */
221  int64_t pkt_dts;
222 
223  /**
224  * picture number in bitstream order
225  */
227  /**
228  * picture number in display order
229  */
231 
232  /**
233  * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
234  */
235  int quality;
236 
237 #if FF_API_AVFRAME_LAVC
240 
241  /**
242  * QP table
243  */
245  int8_t *qscale_table;
246  /**
247  * QP store stride
248  */
250  int qstride;
251 
254 
255  /**
256  * mbskip_table[mb]>=1 if MB didn't change
257  * stride= mb_width = (width+15)>>4
258  */
261 
262  /**
263  * motion vector table
264  * @code
265  * example:
266  * int mv_sample_log2= 4 - motion_subsample_log2;
267  * int mb_width= (width+15)>>4;
268  * int mv_stride= (mb_width << mv_sample_log2) + 1;
269  * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
270  * @endcode
271  */
272  int16_t (*motion_val[2])[2];
273 
274  /**
275  * macroblock type table
276  * mb_type_base + mb_width + 2
277  */
279  uint32_t *mb_type;
280 
281  /**
282  * DCT coefficients
283  */
285  short *dct_coeff;
286 
287  /**
288  * motion reference frame index
289  * the order in which these are stored can depend on the codec.
290  */
292  int8_t *ref_index[2];
293 #endif
294 
295  /**
296  * for some private data of the user
297  */
298  void *opaque;
299 
300  /**
301  * error
302  */
304 
305 #if FF_API_AVFRAME_LAVC
307  int type;
308 #endif
309 
310  /**
311  * When decoding, this signals how much the picture must be delayed.
312  * extra_delay = repeat_pict / (2*fps)
313  */
315 
316  /**
317  * The content of the picture is interlaced.
318  */
320 
321  /**
322  * If the content is interlaced, is top field displayed first.
323  */
325 
326  /**
327  * Tell user application that palette has changed from previous frame.
328  */
330 
331 #if FF_API_AVFRAME_LAVC
334 
335  /**
336  * Pan scan.
337  */
340 #endif
341 
342  /**
343  * reordered opaque 64bit (generally an integer or a double precision float
344  * PTS but can be anything).
345  * The user sets AVCodecContext.reordered_opaque to represent the input at
346  * that time,
347  * the decoder reorders values as needed and sets AVFrame.reordered_opaque
348  * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
349  * @deprecated in favor of pkt_pts
350  */
352 
353 #if FF_API_AVFRAME_LAVC
354  /**
355  * @deprecated this field is unused
356  */
358 
363 
364  /**
365  * log2 of the size of the block which a single vector in motion_val represents:
366  * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
367  */
369 #endif
370 
371  /**
372  * Sample rate of the audio data.
373  */
375 
376  /**
377  * Channel layout of the audio data.
378  */
379  uint64_t channel_layout;
380 
381  /**
382  * AVBuffer references backing the data for this frame. If all elements of
383  * this array are NULL, then this frame is not reference counted.
384  *
385  * There may be at most one AVBuffer per data plane, so for video this array
386  * always contains all the references. For planar audio with more than
387  * AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
388  * this array. Then the extra AVBufferRef pointers are stored in the
389  * extended_buf array.
390  */
392 
393  /**
394  * For planar audio which requires more than AV_NUM_DATA_POINTERS
395  * AVBufferRef pointers, this array will hold all the references which
396  * cannot fit into AVFrame.buf.
397  *
398  * Note that this is different from AVFrame.extended_data, which always
399  * contains all the pointers. This array only contains the extra pointers,
400  * which cannot fit into AVFrame.buf.
401  *
402  * This array is always allocated using av_malloc() by whoever constructs
403  * the frame. It is freed in av_frame_unref().
404  */
406  /**
407  * Number of elements in extended_buf.
408  */
410 
413 
414 /**
415  * @defgroup lavu_frame_flags AV_FRAME_FLAGS
416  * Flags describing additional frame properties.
417  *
418  * @{
419  */
420 
421 /**
422  * The frame data may be corrupted, e.g. due to decoding errors.
423  */
424 #define AV_FRAME_FLAG_CORRUPT (1 << 0)
425 /**
426  * @}
427  */
428 
429  /**
430  * Frame flags, a combination of @ref lavu_frame_flags
431  */
432  int flags;
433 
434 #if FF_API_AVFRAME_COLORSPACE
435  /**
436  * MPEG vs JPEG YUV range.
437  * It must be accessed using av_frame_get_color_range() and
438  * av_frame_set_color_range().
439  * - encoding: Set by user
440  * - decoding: Set by libavcodec
441  */
443 
445 
447 
448  /**
449  * YUV colorspace type.
450  * It must be accessed using av_frame_get_colorspace() and
451  * av_frame_set_colorspace().
452  * - encoding: Set by user
453  * - decoding: Set by libavcodec
454  */
456 
458 #endif
459 
460  /**
461  * frame timestamp estimated using various heuristics, in stream time base
462  * Code outside libavcodec should access this field using:
463  * av_frame_get_best_effort_timestamp(frame)
464  * - encoding: unused
465  * - decoding: set by libavcodec, read by user.
466  */
468 
469  /**
470  * reordered pos from the last AVPacket that has been input into the decoder
471  * Code outside libavcodec should access this field using:
472  * av_frame_get_pkt_pos(frame)
473  * - encoding: unused
474  * - decoding: Read by user.
475  */
476  int64_t pkt_pos;
477 
478  /**
479  * duration of the corresponding packet, expressed in
480  * AVStream->time_base units, 0 if unknown.
481  * Code outside libavcodec should access this field using:
482  * av_frame_get_pkt_duration(frame)
483  * - encoding: unused
484  * - decoding: Read by user.
485  */
486  int64_t pkt_duration;
487 
488  /**
489  * metadata.
490  * Code outside libavcodec should access this field using:
491  * av_frame_get_metadata(frame)
492  * - encoding: Set by user.
493  * - decoding: Set by libavcodec.
494  */
496 
497  /**
498  * decode error flags of the frame, set to a combination of
499  * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
500  * were errors during the decoding.
501  * Code outside libavcodec should access this field using:
502  * av_frame_get_decode_error_flags(frame)
503  * - encoding: unused
504  * - decoding: set by libavcodec, read by user.
505  */
507 #define FF_DECODE_ERROR_INVALID_BITSTREAM 1
508 #define FF_DECODE_ERROR_MISSING_REFERENCE 2
509 
510  /**
511  * number of audio channels, only used for audio.
512  * Code outside libavcodec should access this field using:
513  * av_frame_get_channels(frame)
514  * - encoding: unused
515  * - decoding: Read by user.
516  */
517  int channels;
518 
519  /**
520  * size of the corresponding packet containing the compressed
521  * frame. It must be accessed using av_frame_get_pkt_size() and
522  * av_frame_set_pkt_size().
523  * It is set to a negative value if unknown.
524  * - encoding: unused
525  * - decoding: set by libavcodec, read by user.
526  */
527  int pkt_size;
528 
529  /**
530  * Not to be accessed directly from outside libavutil
531  */
533 } AVFrame;
534 
535 /**
536  * Accessors for some AVFrame fields.
537  * The position of these field in the structure is not part of the ABI,
538  * they should not be accessed directly outside libavcodec.
539  */
542 int64_t av_frame_get_pkt_duration (const AVFrame *frame);
543 void av_frame_set_pkt_duration (AVFrame *frame, int64_t val);
544 int64_t av_frame_get_pkt_pos (const AVFrame *frame);
545 void av_frame_set_pkt_pos (AVFrame *frame, int64_t val);
546 int64_t av_frame_get_channel_layout (const AVFrame *frame);
548 int av_frame_get_channels (const AVFrame *frame);
559 int8_t *av_frame_get_qp_table(AVFrame *f, int *stride, int *type);
565 
566 /**
567  * Get the name of a colorspace.
568  * @return a static string identifying the colorspace; can be NULL.
569  */
570 const char *av_get_colorspace_name(enum AVColorSpace val);
571 
572 /**
573  * Allocate an AVFrame and set its fields to default values. The resulting
574  * struct must be freed using av_frame_free().
575  *
576  * @return An AVFrame filled with default values or NULL on failure.
577  *
578  * @note this only allocates the AVFrame itself, not the data buffers. Those
579  * must be allocated through other means, e.g. with av_frame_get_buffer() or
580  * manually.
581  */
582 AVFrame *av_frame_alloc(void);
583 
584 /**
585  * Free the frame and any dynamically allocated objects in it,
586  * e.g. extended_data. If the frame is reference counted, it will be
587  * unreferenced first.
588  *
589  * @param frame frame to be freed. The pointer will be set to NULL.
590  */
591 void av_frame_free(AVFrame **frame);
592 
593 /**
594  * Set up a new reference to the data described by the source frame.
595  *
596  * Copy frame properties from src to dst and create a new reference for each
597  * AVBufferRef from src.
598  *
599  * If src is not reference counted, new buffers are allocated and the data is
600  * copied.
601  *
602  * @return 0 on success, a negative AVERROR on error
603  */
604 int av_frame_ref(AVFrame *dst, const AVFrame *src);
605 
606 /**
607  * Create a new frame that references the same data as src.
608  *
609  * This is a shortcut for av_frame_alloc()+av_frame_ref().
610  *
611  * @return newly created AVFrame on success, NULL on error.
612  */
614 
615 /**
616  * Unreference all the buffers referenced by frame and reset the frame fields.
617  */
619 
620 /**
621  * Move everythnig contained in src to dst and reset src.
622  */
623 void av_frame_move_ref(AVFrame *dst, AVFrame *src);
624 
625 /**
626  * Allocate new buffer(s) for audio or video data.
627  *
628  * The following fields must be set on frame before calling this function:
629  * - format (pixel format for video, sample format for audio)
630  * - width and height for video
631  * - nb_samples and channel_layout for audio
632  *
633  * This function will fill AVFrame.data and AVFrame.buf arrays and, if
634  * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
635  * For planar formats, one buffer will be allocated for each plane.
636  *
637  * @param frame frame in which to store the new buffers.
638  * @param align required buffer size alignment
639  *
640  * @return 0 on success, a negative AVERROR on error.
641  */
643 
644 /**
645  * Check if the frame data is writable.
646  *
647  * @return A positive value if the frame data is writable (which is true if and
648  * only if each of the underlying buffers has only one reference, namely the one
649  * stored in this frame). Return 0 otherwise.
650  *
651  * If 1 is returned the answer is valid until av_buffer_ref() is called on any
652  * of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
653  *
654  * @see av_frame_make_writable(), av_buffer_is_writable()
655  */
657 
658 /**
659  * Ensure that the frame data is writable, avoiding data copy if possible.
660  *
661  * Do nothing if the frame is writable, allocate new buffers and copy the data
662  * if it is not.
663  *
664  * @return 0 on success, a negative AVERROR on error.
665  *
666  * @see av_frame_is_writable(), av_buffer_is_writable(),
667  * av_buffer_make_writable()
668  */
670 
671 /**
672  * Copy the frame data from src to dst.
673  *
674  * This function does not allocate anything, dst must be already initialized and
675  * allocated with the same parameters as src.
676  *
677  * This function only copies the frame data (i.e. the contents of the data /
678  * extended data arrays), not any other properties.
679  *
680  * @return >= 0 on success, a negative AVERROR on error.
681  */
682 int av_frame_copy(AVFrame *dst, const AVFrame *src);
683 
684 /**
685  * Copy only "metadata" fields from src to dst.
686  *
687  * Metadata for the purpose of this function are those fields that do not affect
688  * the data layout in the buffers. E.g. pts, sample rate (for audio) or sample
689  * aspect ratio (for video), but not width/height or channel layout.
690  * Side data is also copied.
691  */
692 int av_frame_copy_props(AVFrame *dst, const AVFrame *src);
693 
694 /**
695  * Get the buffer reference a given data plane is stored in.
696  *
697  * @param plane index of the data plane of interest in frame->extended_data.
698  *
699  * @return the buffer reference that contains the plane or NULL if the input
700  * frame is not valid.
701  */
703 
704 /**
705  * Add a new side data to a frame.
706  *
707  * @param frame a frame to which the side data should be added
708  * @param type type of the added side data
709  * @param size size of the side data
710  *
711  * @return newly added side data on success, NULL on error
712  */
715  int size);
716 
717 /**
718  * @return a pointer to the side data of a given type on success, NULL if there
719  * is no side data with such type in this frame.
720  */
723 
724 /**
725  * If side data of the supplied type exists in the frame, free it and remove it
726  * from the frame.
727  */
729 
730 /**
731  * @return a string identifying the side data type
732  */
734 
735 /**
736  * @}
737  */
738 
739 #endif /* AVUTIL_FRAME_H */