FFmpeg
target_dec_fuzzer.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /* Targeted fuzzer that targets specific codecs depending on two
20  compile-time flags.
21  INSTRUCTIONS:
22 
23  * Get the very fresh clang, e.g. see http://libfuzzer.info#versions
24  * Get and build libFuzzer:
25  svn co http://llvm.org/svn/llvm-project/llvm/trunk/lib/Fuzzer
26  ./Fuzzer/build.sh
27  * build ffmpeg for fuzzing:
28  FLAGS="-fsanitize=address -fsanitize-coverage=trace-pc-guard,trace-cmp -g" CC="clang $FLAGS" CXX="clang++ $FLAGS" ./configure --disable-x86asm
29  make clean && make -j
30  * build the fuzz target.
31  Choose the value of FFMPEG_CODEC (e.g. AV_CODEC_ID_DVD_SUBTITLE) and
32  choose one of FUZZ_FFMPEG_VIDEO, FUZZ_FFMPEG_AUDIO, FUZZ_FFMPEG_SUBTITLE.
33  clang -fsanitize=address -fsanitize-coverage=trace-pc-guard,trace-cmp tools/target_dec_fuzzer.c -o target_dec_fuzzer -I. -DFFMPEG_CODEC=AV_CODEC_ID_MPEG1VIDEO -DFUZZ_FFMPEG_VIDEO ../../libfuzzer/libFuzzer.a -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,--as-needed -Wl,-z,noexecstack -Wl,--warn-common -Wl,-rpath-link=:libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample -lavdevice -lavfilter -lavformat -lavcodec -lswresample -lswscale -lavutil -ldl -lxcb -lxcb-shm -lxcb -lxcb-xfixes -lxcb -lxcb-shape -lxcb -lX11 -lasound -lm -lbz2 -lz -pthread
34  * create a corpus directory and put some samples there (empty dir is ok too):
35  mkdir CORPUS && cp some-files CORPUS
36 
37  * Run fuzzing:
38  ./target_dec_fuzzer -max_len=100000 CORPUS
39 
40  More info:
41  http://libfuzzer.info
42  http://tutorial.libfuzzer.info
43  https://github.com/google/oss-fuzz
44  http://lcamtuf.coredump.cx/afl/
45  https://security.googleblog.com/2016/08/guided-in-process-fuzzing-of-chrome.html
46 */
47 
48 #include "config.h"
49 #include "libavutil/avassert.h"
50 #include "libavutil/imgutils.h"
51 #include "libavutil/intreadwrite.h"
52 
53 #include "libavcodec/avcodec.h"
54 #include "libavcodec/bytestream.h"
55 #include "libavformat/avformat.h"
56 
57 //For FF_SANE_NB_CHANNELS, so we dont waste energy testing things that will get instantly rejected
58 #include "libavcodec/internal.h"
59 
60 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
61 
62 extern AVCodec * codec_list[];
63 
64 static void error(const char *err)
65 {
66  fprintf(stderr, "%s", err);
67  exit(1);
68 }
69 
70 static AVCodec *c = NULL;
72 {
73  AVCodec *res;
74 
75  res = avcodec_find_decoder(codec_id);
76  if (!res)
77  error("Failed to find decoder");
78  return res;
79 }
80 
81 static int subtitle_handler(AVCodecContext *avctx, void *frame,
82  int *got_sub_ptr, AVPacket *avpkt)
83 {
84  AVSubtitle sub;
85  int ret = avcodec_decode_subtitle2(avctx, &sub, got_sub_ptr, avpkt);
86  if (ret >= 0 && *got_sub_ptr)
87  avsubtitle_free(&sub);
88  return ret;
89 }
90 
91 // Ensure we don't loop forever
92 const uint32_t maxiteration = 8096;
93 const uint64_t maxpixels_per_frame = 4096 * 4096;
94 uint64_t maxpixels;
95 
96 const uint64_t maxsamples_per_frame = 256*1024*32;
97 uint64_t maxsamples;
98 
99 static const uint64_t FUZZ_TAG = 0x4741542D5A5A5546ULL;
100 
102  const uint64_t fuzz_tag = FUZZ_TAG;
103  const uint8_t *last = data;
104  const uint8_t *end = data + size;
105  uint32_t it = 0;
106  uint64_t ec_pixels = 0;
107  uint64_t nb_samples = 0;
108  int (*decode_handler)(AVCodecContext *avctx, AVFrame *picture,
109  int *got_picture_ptr,
110  const AVPacket *avpkt) = NULL;
111  AVCodecParserContext *parser = NULL;
112  uint64_t keyframes = 0;
113 
114 
115  if (!c) {
116 #ifdef FFMPEG_DECODER
117 #define DECODER_SYMBOL0(CODEC) ff_##CODEC##_decoder
118 #define DECODER_SYMBOL(CODEC) DECODER_SYMBOL0(CODEC)
119  extern AVCodec DECODER_SYMBOL(FFMPEG_DECODER);
120  codec_list[0] = &DECODER_SYMBOL(FFMPEG_DECODER);
121  avcodec_register(&DECODER_SYMBOL(FFMPEG_DECODER));
122 
123  c = &DECODER_SYMBOL(FFMPEG_DECODER);
124 #else
126  c = AVCodecInitialize(FFMPEG_CODEC); // Done once.
127 #endif
129  }
130 
131  switch (c->type) {
132  case AVMEDIA_TYPE_AUDIO : decode_handler = avcodec_decode_audio4; break;
133  case AVMEDIA_TYPE_VIDEO : decode_handler = avcodec_decode_video2; break;
134  case AVMEDIA_TYPE_SUBTITLE: decode_handler = subtitle_handler ; break;
135  }
138  switch (c->id) {
139  // Allows a small input to generate gigantic output
140  case AV_CODEC_ID_BINKVIDEO: maxpixels /= 32; break;
141  case AV_CODEC_ID_CFHD: maxpixels /= 128; break;
142  case AV_CODEC_ID_DIRAC: maxpixels /= 8192; break;
143  case AV_CODEC_ID_DXV: maxpixels /= 32; break;
144  case AV_CODEC_ID_FFWAVESYNTH: maxsamples /= 16384; break;
145  case AV_CODEC_ID_MSRLE: maxpixels /= 16; break;
146  case AV_CODEC_ID_QTRLE: maxpixels /= 16; break;
147  case AV_CODEC_ID_SANM: maxpixels /= 16; break;
148  case AV_CODEC_ID_G2M: maxpixels /= 64; break;
149  case AV_CODEC_ID_GIF: maxpixels /= 16; break;
150  // Performs slow frame rescaling in C
151  case AV_CODEC_ID_GDV: maxpixels /= 512; break;
152  // Postprocessing in C
153  case AV_CODEC_ID_HNM4_VIDEO:maxpixels /= 128; break;
154  // Cliping in C, generally slow even with small input
155  case AV_CODEC_ID_INDEO4: maxpixels /= 128; break;
156  case AV_CODEC_ID_LSCR: maxpixels /= 16; break;
157  case AV_CODEC_ID_MOTIONPIXELS:maxpixels /= 256; break;
158  case AV_CODEC_ID_MSS2: maxpixels /= 16384; break;
159  case AV_CODEC_ID_MSZH: maxpixels /= 128; break;
160  case AV_CODEC_ID_SCPR: maxpixels /= 32; break;
161  case AV_CODEC_ID_SMACKVIDEO: maxpixels /= 64; break;
162  case AV_CODEC_ID_SNOW: maxpixels /= 128; break;
163  case AV_CODEC_ID_TGV: maxpixels /= 32; break;
164  case AV_CODEC_ID_TRUEMOTION2: maxpixels /= 1024; break;
165  case AV_CODEC_ID_VP7: maxpixels /= 256; break;
166  }
167 
168 
170  AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
171  if (!ctx || !parser_avctx)
172  error("Failed memory allocation");
173 
174  if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
175  ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
176  ctx->refcounted_frames = 1; //To reduce false positive timeouts and focus testing on the refcounted API
177 
179 
180  if (size > 1024) {
181  GetByteContext gbc;
182  int extradata_size;
183  int flags;
184  size -= 1024;
185  bytestream2_init(&gbc, data + size, 1024);
186  ctx->width = bytestream2_get_le32(&gbc);
187  ctx->height = bytestream2_get_le32(&gbc);
188  ctx->bit_rate = bytestream2_get_le64(&gbc);
189  ctx->bits_per_coded_sample = bytestream2_get_le32(&gbc);
190  // Try to initialize a parser for this codec, note, this may fail which just means we test without one
191  flags = bytestream2_get_byte(&gbc);
192  if (flags & 1)
193  parser = av_parser_init(c->id);
194  if (flags & 2)
196 
197  extradata_size = bytestream2_get_le32(&gbc);
198 
199  ctx->sample_rate = bytestream2_get_le32(&gbc);
200  ctx->channels = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
201  ctx->block_align = bytestream2_get_le32(&gbc);
202  ctx->codec_tag = bytestream2_get_le32(&gbc);
203  keyframes = bytestream2_get_le64(&gbc);
204 
205  if (extradata_size < size) {
206  ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
207  if (ctx->extradata) {
208  ctx->extradata_size = extradata_size;
209  size -= ctx->extradata_size;
210  memcpy(ctx->extradata, data + size, ctx->extradata_size);
211  }
212  }
213  if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
214  ctx->width = ctx->height = 0;
215  }
216 
217  int res = avcodec_open2(ctx, c, NULL);
218  if (res < 0) {
219  avcodec_free_context(&ctx);
220  av_free(parser_avctx);
221  av_parser_close(parser);
222  return 0; // Failure of avcodec_open2() does not imply that a issue was found
223  }
224  parser_avctx->codec_id = ctx->codec_id;
225 
226  int got_frame;
228  if (!frame)
229  error("Failed memory allocation");
230 
231  // Read very simple container
232  AVPacket avpkt, parsepkt;
233  av_init_packet(&avpkt);
234  av_init_packet(&parsepkt);
235  while (data < end && it < maxiteration) {
236  // Search for the TAG
237  while (data + sizeof(fuzz_tag) < end) {
238  if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
239  break;
240  data++;
241  }
242  if (data + sizeof(fuzz_tag) > end)
243  data = end;
244 
245  res = av_new_packet(&parsepkt, data - last);
246  if (res < 0)
247  error("Failed memory allocation");
248  memcpy(parsepkt.data, last, data - last);
249  parsepkt.flags = (keyframes & 1) * AV_PKT_FLAG_DISCARD + (!!(keyframes & 2)) * AV_PKT_FLAG_KEY;
250  keyframes = (keyframes >> 2) + (keyframes<<62);
251  data += sizeof(fuzz_tag);
252  last = data;
253 
254  while (parsepkt.size > 0) {
255 
256  if (parser) {
257  av_init_packet(&avpkt);
258  int ret = av_parser_parse2(parser, parser_avctx, &avpkt.data, &avpkt.size,
259  parsepkt.data, parsepkt.size,
260  parsepkt.pts, parsepkt.dts, parsepkt.pos);
261  if (avpkt.data == parsepkt.data) {
262  avpkt.buf = av_buffer_ref(parsepkt.buf);
263  if (!avpkt.buf)
264  error("Failed memory allocation");
265  } else {
266  if (av_packet_make_refcounted(&avpkt) < 0)
267  error("Failed memory allocation");
268  }
269  parsepkt.data += ret;
270  parsepkt.size -= ret;
271  parsepkt.pos += ret;
272  avpkt.pts = parser->pts;
273  avpkt.dts = parser->dts;
274  avpkt.pos = parser->pos;
275  if ( parser->key_frame == 1 ||
276  (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
277  avpkt.flags |= AV_PKT_FLAG_KEY;
278  avpkt.flags |= parsepkt.flags & AV_PKT_FLAG_DISCARD;
279  } else {
280  av_packet_move_ref(&avpkt, &parsepkt);
281  }
282 
283  // Iterate through all data
284  while (avpkt.size > 0 && it++ < maxiteration) {
285  av_frame_unref(frame);
286  int ret = decode_handler(ctx, frame, &got_frame, &avpkt);
287 
288  ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
289  if (it > 20 || ec_pixels > 4 * ctx->max_pixels)
290  ctx->error_concealment = 0;
291  if (ec_pixels > maxpixels)
292  goto maximums_reached;
293 
294  nb_samples += frame->nb_samples;
295  if (nb_samples > maxsamples)
296  goto maximums_reached;
297 
298  if (ret <= 0 || ret > avpkt.size)
299  break;
300  if (ctx->codec_type != AVMEDIA_TYPE_AUDIO)
301  ret = avpkt.size;
302  avpkt.data += ret;
303  avpkt.size -= ret;
304  }
305  av_packet_unref(&avpkt);
306  }
307  av_packet_unref(&parsepkt);
308  }
309 maximums_reached:
310 
311  av_packet_unref(&avpkt);
312 
313  do {
314  got_frame = 0;
315  av_frame_unref(frame);
316  decode_handler(ctx, frame, &got_frame, &avpkt);
317  } while (got_frame == 1 && it++ < maxiteration);
318 
319  fprintf(stderr, "pixels decoded: %"PRId64", samples decoded: %"PRId64", iterations: %d\n", ec_pixels, nb_samples, it);
320 
321  av_frame_free(&frame);
322  avcodec_free_context(&ctx);
323  avcodec_free_context(&parser_avctx);
324  av_parser_close(parser);
325  av_packet_unref(&parsepkt);
326  return 0;
327 }
#define FF_SANE_NB_CHANNELS
Definition: internal.h:86
#define FF_COMPLIANCE_EXPERIMENTAL
Allow nonstandardized experimental things.
Definition: avcodec.h:2636
const uint32_t maxiteration
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
uint64_t maxsamples
misc image utilities
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1618
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1500
void av_log_set_level(int level)
Set the log level.
Definition: log.c:385
enum AVCodecID codec_id
Definition: qsv.c:77
int size
Definition: avcodec.h:1481
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
attribute_deprecated int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, const AVPacket *avpkt)
Decode the audio frame of size avpkt->size from avpkt->data into frame.
Definition: decode.c:904
enum AVMediaType type
Definition: avcodec.h:3505
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub_ptr, AVPacket *avpkt)
Decode a subtitle message.
Definition: decode.c:1069
AVCodec.
Definition: avcodec.h:3492
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2265
uint8_t
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
#define AV_LOG_PANIC
Something went really wrong and we will crash now.
Definition: log.h:163
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1669
uint8_t * data
Definition: avcodec.h:1480
s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s it
void av_packet_move_ref(AVPacket *dst, AVPacket *src)
Move every field in src to dst and reset src.
Definition: avpacket.c:655
av_cold void avcodec_register(AVCodec *codec)
Register the codec codec and initialize libavcodec.
Definition: allcodecs.c:839
ptrdiff_t size
Definition: opengl_enc.c:100
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2792
void avcodec_register_all(void)
Register all the codecs, parsers and bitstream filters which were enabled at configuration time...
Definition: allcodecs.c:854
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1512
static AVCodec * c
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
enum AVCodecID id
Definition: avcodec.h:3506
static const uint64_t FUZZ_TAG
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:215
int64_t pos
Byte position of currently parsed frame in stream.
Definition: avcodec.h:5229
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
int error_concealment
error concealment flags
Definition: avcodec.h:2643
AVBufferRef * buf
A reference to the reference-counted buffer where the packet data is stored.
Definition: avcodec.h:1463
simple assert() macros that are a bit more flexible than ISO C assert().
int64_t max_pixels
The number of pixels per image to maximally accept.
Definition: avcodec.h:3295
const uint64_t maxpixels_per_frame
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1486
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:282
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:156
int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int64_t pts, int64_t dts, int64_t pos)
Parse a packet.
Definition: parser.c:120
static AVCodec * AVCodecInitialize(enum AVCodecID codec_id)
int width
picture width / height.
Definition: avcodec.h:1741
int av_packet_make_refcounted(AVPacket *pkt)
Ensure the data described by a given packet is reference counted.
Definition: avpacket.c:663
AVFormatContext * ctx
Definition: movenc.c:48
void av_parser_close(AVCodecParserContext *s)
Definition: parser.c:224
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
static void error(const char *err)
static int subtitle_handler(AVCodecContext *avctx, void *frame, int *got_sub_ptr, AVPacket *avpkt)
AVCodecParserContext * av_parser_init(int codec_id)
Definition: parser.c:34
Libavcodec external API header.
enum AVMediaType codec_type
Definition: avcodec.h:1576
attribute_deprecated int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture, int *got_picture_ptr, const AVPacket *avpkt)
Decode the video frame of size avpkt->size from avpkt->data into picture.
Definition: decode.c:897
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer...
Definition: options.c:171
enum AVCodecID codec_id
Definition: avcodec.h:1578
int sample_rate
samples per second
Definition: avcodec.h:2228
main external API structure.
Definition: avcodec.h:1568
AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:896
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
void avsubtitle_free(AVSubtitle *sub)
Free all allocated data in the given subtitle struct.
Definition: utils.c:1081
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> (&#39;D&#39;<<24) + (&#39;C&#39;<<16) + (&#39;B&#39;<<8) + &#39;A&#39;).
Definition: avcodec.h:1593
int64_t max_samples
The number of samples per frame to maximally accept.
Definition: avcodec.h:3383
int extradata_size
Definition: avcodec.h:1670
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
Definition: utils.c:548
attribute_deprecated int refcounted_frames
If non-zero, the decoded audio and video frames returned from avcodec_decode_video2() and avcodec_dec...
Definition: avcodec.h:2399
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:553
#define flags(name, subs,...)
Definition: cbs_av1.c:561
Main libavformat public API header.
int
#define AV_PKT_FLAG_DISCARD
Flag is used to discard packets which are required to maintain valid decoder state but are not requir...
Definition: avcodec.h:1519
common internal api header.
AVBufferRef * av_buffer_ref(AVBufferRef *buf)
Create a new reference to an AVBuffer.
Definition: buffer.c:93
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:33
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:793
#define av_free(p)
uint64_t maxpixels
int channels
number of audio channels
Definition: avcodec.h:2229
#define AV_RN64(p)
Definition: intreadwrite.h:368
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1479
This structure stores compressed data.
Definition: avcodec.h:1457
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:5168
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:361
int strict_std_compliance
strictly follow the standard (MPEG-4, ...).
Definition: avcodec.h:2631
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1473
AVCodec * codec_list[]
const uint64_t maxsamples_per_frame