FFmpeg  4.4.6
apngdec.c
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1 /*
2  * APNG demuxer
3  * Copyright (c) 2014 Benoit Fouet
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 Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * APNG demuxer.
25  * @see https://wiki.mozilla.org/APNG_Specification
26  * @see http://www.w3.org/TR/PNG
27  */
28 
29 #include "avformat.h"
30 #include "avio_internal.h"
31 #include "internal.h"
32 #include "libavutil/imgutils.h"
33 #include "libavutil/intreadwrite.h"
34 #include "libavutil/opt.h"
35 #include "libavcodec/apng.h"
36 #include "libavcodec/png.h"
37 #include "libavcodec/bytestream.h"
38 
39 #define DEFAULT_APNG_FPS 15
40 
41 typedef struct APNGDemuxContext {
42  const AVClass *class;
43 
44  int max_fps;
46 
48 
50 
51  /*
52  * loop options
53  */
55  uint32_t num_frames;
56  uint32_t num_play;
57  uint32_t cur_loop;
59 
60 /*
61  * To be a valid APNG file, we mandate, in this order:
62  * PNGSIG
63  * IHDR
64  * ...
65  * acTL
66  * ...
67  * IDAT
68  */
69 static int apng_probe(const AVProbeData *p)
70 {
71  GetByteContext gb;
72  int state = 0;
73  uint32_t len, tag;
74 
75  bytestream2_init(&gb, p->buf, p->buf_size);
76 
77  if (bytestream2_get_be64(&gb) != PNGSIG)
78  return 0;
79 
80  for (;;) {
81  len = bytestream2_get_be32(&gb);
82  if (len > 0x7fffffff)
83  return 0;
84 
85  tag = bytestream2_get_le32(&gb);
86  /* we don't check IDAT size, as this is the last tag
87  * we check, and it may be larger than the probe buffer */
88  if (tag != MKTAG('I', 'D', 'A', 'T') &&
90  return 0;
91 
92  switch (tag) {
93  case MKTAG('I', 'H', 'D', 'R'):
94  if (len != 13)
95  return 0;
96  if (av_image_check_size(bytestream2_get_be32(&gb), bytestream2_get_be32(&gb), 0, NULL))
97  return 0;
98  bytestream2_skip(&gb, 9);
99  state++;
100  break;
101  case MKTAG('a', 'c', 'T', 'L'):
102  if (state != 1 ||
103  len != 8 ||
104  bytestream2_get_be32(&gb) == 0) /* 0 is not a valid value for number of frames */
105  return 0;
106  bytestream2_skip(&gb, 8);
107  state++;
108  break;
109  case MKTAG('I', 'D', 'A', 'T'):
110  if (state != 2)
111  return 0;
112  goto end;
113  default:
114  /* skip other tags */
115  bytestream2_skip(&gb, len + 4);
116  break;
117  }
118  }
119 
120 end:
121  return AVPROBE_SCORE_MAX;
122 }
123 
125 {
126  int previous_size = par->extradata_size;
127  int new_size, ret;
128  uint8_t *new_extradata;
129 
130  if (len > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE - previous_size)
131  return AVERROR_INVALIDDATA;
132 
133  new_size = previous_size + len;
134  new_extradata = av_realloc(par->extradata, new_size + AV_INPUT_BUFFER_PADDING_SIZE);
135  if (!new_extradata)
136  return AVERROR(ENOMEM);
137  memset(new_extradata + new_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
138  par->extradata = new_extradata;
139  par->extradata_size = new_size;
140 
141  if ((ret = ffio_read_size(pb, par->extradata + previous_size, len)) < 0)
142  return ret;
143 
144  return previous_size;
145 }
146 
148 {
149  APNGDemuxContext *ctx = s->priv_data;
150  AVIOContext *pb = s->pb;
151  uint32_t len, tag;
152  AVStream *st;
153  int acTL_found = 0;
154  int64_t ret;
155 
156  /* verify PNGSIG */
157  if (avio_rb64(pb) != PNGSIG)
158  return AVERROR_INVALIDDATA;
159 
160  /* parse IHDR (must be first chunk) */
161  len = avio_rb32(pb);
162  tag = avio_rl32(pb);
163  if (len != 13 || tag != MKTAG('I', 'H', 'D', 'R'))
164  return AVERROR_INVALIDDATA;
165 
166  st = avformat_new_stream(s, NULL);
167  if (!st)
168  return AVERROR(ENOMEM);
169 
170  /* set the timebase to something large enough (1/100,000 of second)
171  * to hopefully cope with all sane frame durations */
172  avpriv_set_pts_info(st, 64, 1, 100000);
175  st->codecpar->width = avio_rb32(pb);
176  st->codecpar->height = avio_rb32(pb);
177  if ((ret = av_image_check_size(st->codecpar->width, st->codecpar->height, 0, s)) < 0)
178  return ret;
179 
180  /* extradata will contain every chunk up to the first fcTL (excluded) */
181  ret = ff_alloc_extradata(st->codecpar, len + 12);
182  if (ret < 0)
183  return ret;
184  AV_WB32(st->codecpar->extradata, len);
185  AV_WL32(st->codecpar->extradata+4, tag);
186  AV_WB32(st->codecpar->extradata+8, st->codecpar->width);
187  AV_WB32(st->codecpar->extradata+12, st->codecpar->height);
188  if ((ret = ffio_read_size(pb, st->codecpar->extradata + 16, 9)) < 0)
189  return ret;
190 
191  while (1) {
192  if (acTL_found && ctx->num_play != 1) {
193  int64_t size = avio_size(pb);
194  int64_t offset = avio_tell(pb);
195  if (size < 0) {
196  return size;
197  } else if (offset < 0) {
198  return offset;
199  } else if ((ret = ffio_ensure_seekback(pb, size - offset)) < 0) {
200  av_log(s, AV_LOG_WARNING, "Could not ensure seekback, will not loop\n");
201  ctx->num_play = 1;
202  }
203  }
204  if ((ctx->num_play == 1 || !acTL_found) &&
205  ((ret = ffio_ensure_seekback(pb, 4 /* len */ + 4 /* tag */)) < 0))
206  return ret;
207 
208  len = avio_rb32(pb);
209  if (len > INT_MAX - 12)
210  return AVERROR_INVALIDDATA;
211 
212  tag = avio_rl32(pb);
213  switch (tag) {
214  case MKTAG('a', 'c', 'T', 'L'):
215  if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
216  (ret = append_extradata(st->codecpar, pb, len + 12)) < 0)
217  return ret;
218  acTL_found = 1;
219  ctx->num_frames = AV_RB32(st->codecpar->extradata + ret + 8);
220  ctx->num_play = AV_RB32(st->codecpar->extradata + ret + 12);
221  av_log(s, AV_LOG_DEBUG, "num_frames: %"PRIu32", num_play: %"PRIu32"\n",
222  ctx->num_frames, ctx->num_play);
223  break;
224  case MKTAG('f', 'c', 'T', 'L'):
225  if (!acTL_found || len != 26) {
226  return AVERROR_INVALIDDATA;
227  }
228  if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0)
229  return ret;
230  return 0;
231  default:
232  if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
233  (ret = append_extradata(st->codecpar, pb, len + 12)) < 0)
234  return ret;
235  }
236  }
237 }
238 
240 {
241  uint32_t sequence_number, width, height, x_offset, y_offset;
242  uint16_t delay_num, delay_den;
243  uint8_t dispose_op, blend_op;
244 
245  sequence_number = avio_rb32(s->pb);
246  width = avio_rb32(s->pb);
247  height = avio_rb32(s->pb);
248  x_offset = avio_rb32(s->pb);
249  y_offset = avio_rb32(s->pb);
250  delay_num = avio_rb16(s->pb);
251  delay_den = avio_rb16(s->pb);
252  dispose_op = avio_r8(s->pb);
253  blend_op = avio_r8(s->pb);
254  avio_skip(s->pb, 4); /* crc */
255 
256  /* default is hundredths of seconds */
257  if (!delay_den)
258  delay_den = 100;
259  if (!delay_num || (ctx->max_fps && delay_den / delay_num > ctx->max_fps)) {
260  delay_num = 1;
261  delay_den = ctx->default_fps;
262  }
263  ctx->pkt_duration = av_rescale_q(delay_num,
264  (AVRational){ 1, delay_den },
265  s->streams[0]->time_base);
266 
267  av_log(s, AV_LOG_DEBUG, "%s: "
268  "sequence_number: %"PRId32", "
269  "width: %"PRIu32", "
270  "height: %"PRIu32", "
271  "x_offset: %"PRIu32", "
272  "y_offset: %"PRIu32", "
273  "delay_num: %"PRIu16", "
274  "delay_den: %"PRIu16", "
275  "dispose_op: %d, "
276  "blend_op: %d\n",
277  __FUNCTION__,
278  sequence_number,
279  width,
280  height,
281  x_offset,
282  y_offset,
283  delay_num,
284  delay_den,
285  dispose_op,
286  blend_op);
287 
288  if (width != s->streams[0]->codecpar->width ||
289  height != s->streams[0]->codecpar->height ||
290  x_offset != 0 ||
291  y_offset != 0) {
292  if (sequence_number == 0 ||
293  x_offset >= s->streams[0]->codecpar->width ||
294  width > s->streams[0]->codecpar->width - x_offset ||
295  y_offset >= s->streams[0]->codecpar->height ||
296  height > s->streams[0]->codecpar->height - y_offset)
297  return AVERROR_INVALIDDATA;
298  ctx->is_key_frame = 0;
299  } else {
300  if (sequence_number == 0 && dispose_op == APNG_DISPOSE_OP_PREVIOUS)
301  dispose_op = APNG_DISPOSE_OP_BACKGROUND;
302  ctx->is_key_frame = dispose_op == APNG_DISPOSE_OP_BACKGROUND ||
303  blend_op == APNG_BLEND_OP_SOURCE;
304  }
305 
306  return 0;
307 }
308 
310 {
311  APNGDemuxContext *ctx = s->priv_data;
312  int64_t ret;
313  int64_t size;
314  AVIOContext *pb = s->pb;
315  uint32_t len, tag;
316 
317  /*
318  * fcTL chunk length, in bytes:
319  * 4 (length)
320  * 4 (tag)
321  * 26 (actual chunk)
322  * 4 (crc) bytes
323  * and needed next:
324  * 4 (length)
325  * 4 (tag (must be fdAT or IDAT))
326  */
327  /* if num_play is not 1, then the seekback is already guaranteed */
328  if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 46)) < 0)
329  return ret;
330 
331  len = avio_rb32(pb);
332  tag = avio_rl32(pb);
333 
334  if (avio_feof(pb))
335  return AVERROR_EOF;
336 
337  switch (tag) {
338  case MKTAG('f', 'c', 'T', 'L'):
339  if (len != 26)
340  return AVERROR_INVALIDDATA;
341 
342  if ((ret = decode_fctl_chunk(s, ctx, pkt)) < 0)
343  return ret;
344 
345  /* fcTL must precede fdAT or IDAT */
346  len = avio_rb32(pb);
347  tag = avio_rl32(pb);
348  if (len > 0x7fffffff ||
349  tag != MKTAG('f', 'd', 'A', 'T') &&
350  tag != MKTAG('I', 'D', 'A', 'T'))
351  return AVERROR_INVALIDDATA;
352 
353  size = 38 /* fcTL */ + 8 /* len, tag */ + len + 4 /* crc */;
354  if (size > INT_MAX)
355  return AVERROR(EINVAL);
356 
357  if ((ret = avio_seek(pb, -46, SEEK_CUR)) < 0 ||
358  (ret = av_append_packet(pb, pkt, size)) < 0)
359  return ret;
360 
361  if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0)
362  return ret;
363 
364  len = avio_rb32(pb);
365  tag = avio_rl32(pb);
366  while (tag &&
367  tag != MKTAG('f', 'c', 'T', 'L') &&
368  tag != MKTAG('I', 'E', 'N', 'D')) {
369  if (len > 0x7fffffff)
370  return AVERROR_INVALIDDATA;
371  if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
372  (ret = av_append_packet(pb, pkt, len + 12)) < 0)
373  return ret;
374  if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0)
375  return ret;
376  len = avio_rb32(pb);
377  tag = avio_rl32(pb);
378  }
379  if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0)
380  return ret;
381 
382  if (ctx->is_key_frame)
384  pkt->pts = pkt->dts = AV_NOPTS_VALUE;
385  pkt->duration = ctx->pkt_duration;
386  return ret;
387  case MKTAG('I', 'E', 'N', 'D'):
388  ctx->cur_loop++;
389  if (ctx->ignore_loop || ctx->num_play >= 1 && ctx->cur_loop == ctx->num_play) {
390  avio_seek(pb, -8, SEEK_CUR);
391  return AVERROR_EOF;
392  }
393  if ((ret = avio_seek(pb, s->streams[0]->codecpar->extradata_size + 8, SEEK_SET)) < 0)
394  return ret;
395  return 0;
396  default:
397  avpriv_request_sample(s, "In-stream tag=%s (0x%08"PRIX32") len=%"PRIu32,
398  av_fourcc2str(tag), tag, len);
399  avio_skip(pb, len + 4);
400  }
401 
402  /* Handle the unsupported yet cases */
403  return AVERROR_PATCHWELCOME;
404 }
405 
406 static const AVOption options[] = {
407  { "ignore_loop", "ignore loop setting" , offsetof(APNGDemuxContext, ignore_loop),
408  AV_OPT_TYPE_BOOL, { .i64 = 1 } , 0, 1 , AV_OPT_FLAG_DECODING_PARAM },
409  { "max_fps" , "maximum framerate (0 is no limit)" , offsetof(APNGDemuxContext, max_fps),
410  AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
411  { "default_fps", "default framerate (0 is as fast as possible)", offsetof(APNGDemuxContext, default_fps),
413  { NULL },
414 };
415 
416 static const AVClass demuxer_class = {
417  .class_name = "APNG demuxer",
418  .item_name = av_default_item_name,
419  .option = options,
420  .version = LIBAVUTIL_VERSION_INT,
421  .category = AV_CLASS_CATEGORY_DEMUXER,
422 };
423 
425  .name = "apng",
426  .long_name = NULL_IF_CONFIG_SMALL("Animated Portable Network Graphics"),
427  .priv_data_size = sizeof(APNGDemuxContext),
432  .priv_class = &demuxer_class,
433 };
APNG common header.
@ APNG_DISPOSE_OP_BACKGROUND
Definition: apng.h:32
@ APNG_DISPOSE_OP_PREVIOUS
Definition: apng.h:33
@ APNG_BLEND_OP_SOURCE
Definition: apng.h:37
static int apng_read_header(AVFormatContext *s)
Definition: apngdec.c:147
static int apng_probe(const AVProbeData *p)
Definition: apngdec.c:69
static const AVOption options[]
Definition: apngdec.c:406
static int decode_fctl_chunk(AVFormatContext *s, APNGDemuxContext *ctx, AVPacket *pkt)
Definition: apngdec.c:239
static const AVClass demuxer_class
Definition: apngdec.c:416
static int append_extradata(AVCodecParameters *par, AVIOContext *pb, int len)
Definition: apngdec.c:124
AVInputFormat ff_apng_demuxer
Definition: apngdec.c:424
static int apng_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: apngdec.c:309
#define DEFAULT_APNG_FPS
Definition: apngdec.c:39
uint8_t
Main libavformat public API header.
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:326
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:902
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:342
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:766
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:750
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:781
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
Ensures that the requested seekback buffer size will be available.
Definition: aviobuf.c:998
int ffio_read_size(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:682
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define AV_RB32
Definition: intreadwrite.h:130
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define s(width, name)
Definition: cbs_vp9.c:257
static struct @321 state
#define MKTAG(a, b, c, d)
Definition: common.h:478
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:545
@ AV_OPT_TYPE_INT
Definition: opt.h:225
@ AV_OPT_TYPE_BOOL
Definition: opt.h:242
@ AV_CODEC_ID_APNG
Definition: codec_id.h:264
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition: avcodec.h:215
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:410
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:215
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
void * av_realloc(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory.
Definition: mem.c:134
#define av_fourcc2str(fourcc)
Definition: avutil.h:348
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:317
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
misc image utilities
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
#define AV_WL32(p, v)
Definition: intreadwrite.h:426
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4945
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:3314
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
@ AV_CLASS_CATEGORY_DEMUXER
Definition: log.h:34
uint32_t tag
Definition: movenc.c:1611
AVOptions.
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:279
#define PNGSIG
Definition: png.h:49
uint32_t num_frames
Definition: apngdec.c:55
uint32_t num_play
Definition: apngdec.c:56
uint32_t cur_loop
Definition: apngdec.c:57
int pkt_duration
Definition: apngdec.c:47
int is_key_frame
Definition: apngdec.c:49
Describe the class of an AVClass context structure.
Definition: log.h:67
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
int extradata_size
Size of the extradata content in bytes.
Definition: codec_par.h:78
int width
Video only.
Definition: codec_par.h:126
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
Bytestream IO Context.
Definition: avio.h:161
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVOption.
Definition: opt.h:248
This structure stores compressed data.
Definition: packet.h:346
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:387
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:362
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:368
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Rational number (pair of numerator and denominator).
Definition: rational.h:58
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
#define avpriv_request_sample(...)
#define av_log(a,...)
AVPacket * pkt
Definition: movenc.c:59
AVFormatContext * ctx
Definition: movenc.c:48
#define height
#define width
int size
static const uint8_t offset[127][2]
Definition: vf_spp.c:107
int len