FFmpeg
eamad.c
Go to the documentation of this file.
1 /*
2  * Electronic Arts Madcow Video Decoder
3  * Copyright (c) 2007-2009 Peter Ross
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Electronic Arts Madcow Video Decoder
25  * @author Peter Ross <pross@xvid.org>
26  *
27  * @see technical details at
28  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
29  */
30 
31 #include "libavutil/mem_internal.h"
32 
33 #include "avcodec.h"
34 #include "blockdsp.h"
35 #include "bytestream.h"
36 #include "bswapdsp.h"
37 #include "get_bits.h"
38 #include "aandcttab.h"
39 #include "eaidct.h"
40 #include "idctdsp.h"
41 #include "internal.h"
42 #include "mpeg12data.h"
43 #include "mpeg12vlc.h"
44 
45 #define EA_PREAMBLE_SIZE 8
46 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */
47 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */
48 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
49 
50 typedef struct MadContext {
58  unsigned int bitstream_buf_size;
59  DECLARE_ALIGNED(32, int16_t, block)[64];
61  uint16_t quant_matrix[64];
62  int mb_x;
63  int mb_y;
64 } MadContext;
65 
67 {
68  MadContext *s = avctx->priv_data;
69  s->avctx = avctx;
70  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
71  ff_blockdsp_init(&s->bdsp, avctx);
72  ff_bswapdsp_init(&s->bbdsp);
73  ff_idctdsp_init(&s->idsp, avctx);
74  ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
75  ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
77 
78  s->last_frame = av_frame_alloc();
79  if (!s->last_frame)
80  return AVERROR(ENOMEM);
81 
82  return 0;
83 }
84 
85 static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
86  unsigned char *src, ptrdiff_t src_stride, int add)
87 {
88  int j, i;
89  for (j=0; j<8; j++)
90  for (i=0; i<8; i++)
91  dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
92 }
93 
94 static inline void comp_block(MadContext *t, AVFrame *frame,
95  int mb_x, int mb_y,
96  int j, int mv_x, int mv_y, int add)
97 {
98  if (j < 4) {
99  unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
100  if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
101  return;
102  comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
103  frame->linesize[0],
104  t->last_frame->data[0] + offset,
105  t->last_frame->linesize[0], add);
106  } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
107  int index = j - 3;
108  unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
109  if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
110  return;
111  comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
112  frame->linesize[index],
113  t->last_frame->data[index] + offset,
114  t->last_frame->linesize[index], add);
115  }
116 }
117 
118 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
119  int mb_x, int mb_y, int j)
120 {
121  if (j < 4) {
123  frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
124  frame->linesize[0], block);
125  } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
126  int index = j - 3;
128  frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
129  frame->linesize[index], block);
130  }
131 }
132 
133 static inline int decode_block_intra(MadContext *s, int16_t * block)
134 {
135  int level, i, j, run;
136  RLTable *rl = &ff_rl_mpeg1;
137  const uint8_t *scantable = s->scantable.permutated;
138  int16_t *quant_matrix = s->quant_matrix;
139 
140  block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
141 
142  /* The RL decoder is derived from mpeg1_decode_block_intra;
143  Escaped level and run values a decoded differently */
144  i = 0;
145  {
146  OPEN_READER(re, &s->gb);
147  /* now quantify & encode AC coefficients */
148  for (;;) {
149  UPDATE_CACHE(re, &s->gb);
150  GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
151 
152  if (level == 127) {
153  break;
154  } else if (level != 0) {
155  i += run;
156  if (i > 63) {
157  av_log(s->avctx, AV_LOG_ERROR,
158  "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
159  return -1;
160  }
161  j = scantable[i];
162  level = (level*quant_matrix[j]) >> 4;
163  level = (level-1)|1;
164  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
165  LAST_SKIP_BITS(re, &s->gb, 1);
166  } else {
167  /* escape */
168  UPDATE_CACHE(re, &s->gb);
169  level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
170 
171  UPDATE_CACHE(re, &s->gb);
172  run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
173 
174  i += run;
175  if (i > 63) {
176  av_log(s->avctx, AV_LOG_ERROR,
177  "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
178  return -1;
179  }
180  j = scantable[i];
181  if (level < 0) {
182  level = -level;
183  level = (level*quant_matrix[j]) >> 4;
184  level = (level-1)|1;
185  level = -level;
186  } else {
187  level = (level*quant_matrix[j]) >> 4;
188  level = (level-1)|1;
189  }
190  }
191 
192  block[j] = level;
193  }
194  CLOSE_READER(re, &s->gb);
195  }
196  return 0;
197 }
198 
200 {
201  int value = 0;
202  if (get_bits1(gb)) {
203  if (get_bits1(gb))
204  value = -17;
205  value += get_bits(gb, 4) + 1;
206  }
207  return value;
208 }
209 
210 static int decode_mb(MadContext *s, AVFrame *frame, int inter)
211 {
212  int mv_map = 0;
213  int av_uninit(mv_x), av_uninit(mv_y);
214  int j;
215 
216  if (inter) {
217  int v = decode210(&s->gb);
218  if (v < 2) {
219  mv_map = v ? get_bits(&s->gb, 6) : 63;
220  mv_x = decode_motion(&s->gb);
221  mv_y = decode_motion(&s->gb);
222  }
223  }
224 
225  for (j=0; j<6; j++) {
226  if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
227  int add = 2*decode_motion(&s->gb);
228  if (s->last_frame->data[0])
229  comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
230  } else {
231  s->bdsp.clear_block(s->block);
232  if(decode_block_intra(s, s->block) < 0)
233  return -1;
234  idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
235  }
236  }
237  return 0;
238 }
239 
240 static void calc_quant_matrix(MadContext *s, int qscale)
241 {
242  int i;
243 
244  s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
245  for (i=1; i<64; i++)
246  s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
247 }
248 
249 static int decode_frame(AVCodecContext *avctx,
250  void *data, int *got_frame,
251  AVPacket *avpkt)
252 {
253  const uint8_t *buf = avpkt->data;
254  int buf_size = avpkt->size;
255  MadContext *s = avctx->priv_data;
256  AVFrame *frame = data;
257  GetByteContext gb;
258  int width, height;
259  int chunk_type;
260  int inter, ret;
261 
262  bytestream2_init(&gb, buf, buf_size);
263 
264  chunk_type = bytestream2_get_le32(&gb);
265  inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
266  bytestream2_skip(&gb, 10);
267 
268  av_reduce(&avctx->framerate.den, &avctx->framerate.num,
269  bytestream2_get_le16(&gb), 1000, 1<<30);
270 
271  width = bytestream2_get_le16(&gb);
272  height = bytestream2_get_le16(&gb);
273  bytestream2_skip(&gb, 1);
274  calc_quant_matrix(s, bytestream2_get_byte(&gb));
275  bytestream2_skip(&gb, 2);
276 
277  if (bytestream2_get_bytes_left(&gb) < 2) {
278  av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
279  return AVERROR_INVALIDDATA;
280  }
281 
282  if (width < 16 || height < 16) {
283  av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
284  return AVERROR_INVALIDDATA;
285  }
286 
287  if (avctx->width != width || avctx->height != height) {
288  av_frame_unref(s->last_frame);
289  if((width * (int64_t)height)/2048*7 > bytestream2_get_bytes_left(&gb))
290  return AVERROR_INVALIDDATA;
291  if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
292  return ret;
293  }
294 
295  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
296  return ret;
297 
298  if (inter && !s->last_frame->data[0]) {
299  av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
300  ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
301  if (ret < 0)
302  return ret;
303  memset(s->last_frame->data[0], 0, s->last_frame->height *
304  s->last_frame->linesize[0]);
305  memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
306  s->last_frame->linesize[1]);
307  memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
308  s->last_frame->linesize[2]);
309  }
310 
311  av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
313  if (!s->bitstream_buf)
314  return AVERROR(ENOMEM);
315  s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
316  bytestream2_get_bytes_left(&gb) / 2);
317  memset((uint8_t*)s->bitstream_buf + bytestream2_get_bytes_left(&gb), 0, AV_INPUT_BUFFER_PADDING_SIZE);
318  init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
319 
320  for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
321  for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
322  if(decode_mb(s, frame, inter) < 0)
323  return AVERROR_INVALIDDATA;
324 
325  *got_frame = 1;
326 
327  if (chunk_type != MADe_TAG) {
328  av_frame_unref(s->last_frame);
329  if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
330  return ret;
331  }
332 
333  return buf_size;
334 }
335 
337 {
338  MadContext *t = avctx->priv_data;
340  av_freep(&t->bitstream_buf);
341  return 0;
342 }
343 
345  .name = "eamad",
346  .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
347  .type = AVMEDIA_TYPE_VIDEO,
348  .id = AV_CODEC_ID_MAD,
349  .priv_data_size = sizeof(MadContext),
350  .init = decode_init,
351  .close = decode_end,
352  .decode = decode_frame,
353  .capabilities = AV_CODEC_CAP_DR1,
354  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
355 };
AVCodec
AVCodec.
Definition: codec.h:197
bswapdsp.h
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:187
FF_CODEC_CAP_INIT_THREADSAFE
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
ff_init_scantable
av_cold void ff_init_scantable(uint8_t *permutation, ScanTable *st, const uint8_t *src_scantable)
Definition: idctdsp.c:29
level
uint8_t level
Definition: svq3.c:204
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
blockdsp.h
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
mem_internal.h
comp
static void comp(unsigned char *dst, ptrdiff_t dst_stride, unsigned char *src, ptrdiff_t src_stride, int add)
Definition: eamad.c:85
GetByteContext
Definition: bytestream.h:33
MadContext::bitstream_buf_size
unsigned int bitstream_buf_size
Definition: eamad.c:58
decode_mb
static int decode_mb(MadContext *s, AVFrame *frame, int inter)
Definition: eamad.c:210
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:111
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
index
fg index
Definition: ffmpeg_filter.c:168
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:365
data
const char data[16]
Definition: mxf.c:142
UPDATE_CACHE
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:179
BlockDSPContext
Definition: blockdsp.h:35
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:660
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
AV_CODEC_ID_MAD
@ AV_CODEC_ID_MAD
Definition: codec_id.h:179
AVCodecContext::framerate
AVRational framerate
Definition: avcodec.h:1699
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:380
MadContext::bdsp
BlockDSPContext bdsp
Definition: eamad.c:52
RLTable
RLTable.
Definition: rl.h:39
GetBitContext
Definition: get_bits.h:62
mpeg12vlc.h
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:464
MadContext::idsp
IDCTDSPContext idsp
Definition: eamad.c:54
ff_ea_idct_put_c
void ff_ea_idct_put_c(uint8_t *dest, ptrdiff_t linesize, int16_t *block)
Definition: eaidct.c:80
av_reduce
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
AVRational::num
int num
Numerator.
Definition: rational.h:59
MadContext
Definition: eamad.c:50
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:98
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:181
av_cold
#define av_cold
Definition: attributes.h:90
ff_rl_mpeg1
RLTable ff_rl_mpeg1
Definition: mpeg12data.c:166
CLOSE_READER
#define CLOSE_READER(name, gb)
Definition: get_bits.h:150
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:362
SHOW_SBITS
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:213
get_sbits
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:360
get_bits.h
SKIP_BITS
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:194
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
ff_bswapdsp_init
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
run
uint8_t run
Definition: svq3.c:203
aandcttab.h
MadContext::avctx
AVCodecContext * avctx
Definition: eamad.c:51
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:499
src
#define src
Definition: vp8dsp.c:255
LAST_SKIP_BITS
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:200
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
bytestream2_tell
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
MADe_TAG
#define MADe_TAG
Definition: eamad.c:48
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1638
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AV_CODEC_FLAG_GRAY
#define AV_CODEC_FLAG_GRAY
Only decode/encode grayscale.
Definition: avcodec.h:248
AVPacket::size
int size
Definition: packet.h:366
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
calc_quant_matrix
static void calc_quant_matrix(MadContext *s, int qscale)
Definition: eamad.c:240
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:326
FF_IDCT_PERM_NONE
@ FF_IDCT_PERM_NONE
Definition: idctdsp.h:38
MadContext::scantable
ScanTable scantable
Definition: eamad.c:60
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: eamad.c:336
MadContext::block
int16_t block[64]
Definition: eamad.c:59
ff_mpeg1_default_intra_matrix
const uint16_t ff_mpeg1_default_intra_matrix[256]
Definition: mpeg12data.c:30
MadContext::bbdsp
BswapDSPContext bbdsp
Definition: eamad.c:53
OPEN_READER
#define OPEN_READER(name, gb)
Definition: get_bits.h:139
height
#define height
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
ff_init_scantable_permutation
av_cold void ff_init_scantable_permutation(uint8_t *idct_permutation, enum idct_permutation_type perm_type)
Definition: idctdsp.c:50
DECLARE_ALIGNED
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:116
i
int i
Definition: input.c:407
decode_block_intra
static int decode_block_intra(MadContext *s, int16_t *block)
Definition: eamad.c:133
MadContext::gb
GetBitContext gb
Definition: eamad.c:56
MadContext::bitstream_buf
void * bitstream_buf
Definition: eamad.c:57
ff_mpeg12_init_vlcs
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:165
av_fast_padded_malloc
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
Definition: utils.c:50
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
ff_eamad_decoder
const AVCodec ff_eamad_decoder
Definition: eamad.c:344
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:436
ff_idctdsp_init
av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
Definition: idctdsp.c:238
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:204
AVCodecContext::height
int height
Definition: avcodec.h:557
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:594
idctdsp.h
avcodec.h
GET_RL_VLC
#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)
Definition: get_bits.h:739
ff_zigzag_direct
const uint8_t ff_zigzag_direct[64]
Definition: mathtables.c:98
av_uninit
#define av_uninit(x)
Definition: attributes.h:154
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: eamad.c:66
TEX_VLC_BITS
#define TEX_VLC_BITS
Definition: dvdec.c:132
ff_inv_aanscales
const uint16_t ff_inv_aanscales[64]
Definition: aandcttab.c:38
IDCTDSPContext
Definition: idctdsp.h:53
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
comp_block
static void comp_block(MadContext *t, AVFrame *frame, int mb_x, int mb_y, int j, int mv_x, int mv_y, int add)
Definition: eamad.c:94
mpeg12data.h
AVCodecContext
main external API structure.
Definition: avcodec.h:384
MadContext::last_frame
AVFrame * last_frame
Definition: eamad.c:55
MadContext::mb_y
int mb_y
Definition: eamad.c:63
SHOW_UBITS
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:212
AVRational::den
int den
Denominator.
Definition: rational.h:60
idct_put
static void idct_put(MadContext *t, AVFrame *frame, int16_t *block, int mb_x, int mb_y, int j)
Definition: eamad.c:118
MadContext::mb_x
int mb_x
Definition: eamad.c:62
MADm_TAG
#define MADm_TAG
Definition: eamad.c:47
decode210
static int decode210(GetBitContext *gb)
Definition: get_bits.h:842
av_clip_uint8
#define av_clip_uint8
Definition: common.h:128
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
add
static float add(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:36
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:86
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: eamad.c:249
ScanTable
Scantable.
Definition: idctdsp.h:31
AVPacket
This structure stores compressed data.
Definition: packet.h:342
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:411
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
decode_motion
static int decode_motion(GetBitContext *gb)
Definition: eamad.c:199
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:557
bytestream.h
eaidct.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
BswapDSPContext
Definition: bswapdsp.h:24
MadContext::quant_matrix
uint16_t quant_matrix[64]
Definition: eamad.c:61
ff_blockdsp_init
av_cold void ff_blockdsp_init(BlockDSPContext *c, AVCodecContext *avctx)
Definition: blockdsp.c:60
RLTable::rl_vlc
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
re
float re
Definition: fft.c:82