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;
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_DST: maxsamples /= 8192; break;
144  case AV_CODEC_ID_DXV: maxpixels /= 32; break;
145  case AV_CODEC_ID_FFWAVESYNTH: maxsamples /= 16384; break;
146  case AV_CODEC_ID_MSRLE: maxpixels /= 16; break;
147  case AV_CODEC_ID_QTRLE: maxpixels /= 16; break;
148  case AV_CODEC_ID_RASC: maxpixels /= 16; break;
149  case AV_CODEC_ID_SANM: maxpixels /= 16; break;
150  case AV_CODEC_ID_G2M: maxpixels /= 64; break;
151  case AV_CODEC_ID_GIF: maxpixels /= 16; break;
152  // Performs slow frame rescaling in C
153  case AV_CODEC_ID_GDV: maxpixels /= 512; break;
154  // Postprocessing in C
155  case AV_CODEC_ID_HNM4_VIDEO:maxpixels /= 128; break;
156  // Cliping in C, generally slow even with small input
157  case AV_CODEC_ID_INDEO4: maxpixels /= 128; break;
158  case AV_CODEC_ID_LSCR: maxpixels /= 16; break;
159  case AV_CODEC_ID_MOTIONPIXELS:maxpixels /= 256; break;
160  case AV_CODEC_ID_MSS2: maxpixels /= 16384; break;
161  case AV_CODEC_ID_MSZH: maxpixels /= 128; break;
162  case AV_CODEC_ID_SCPR: maxpixels /= 32; break;
163  case AV_CODEC_ID_SMACKVIDEO: maxpixels /= 64; break;
164  case AV_CODEC_ID_SNOW: maxpixels /= 128; break;
165  case AV_CODEC_ID_TGV: maxpixels /= 32; break;
166  case AV_CODEC_ID_TRUEMOTION2: maxpixels /= 1024; break;
167  case AV_CODEC_ID_VP7: maxpixels /= 256; break;
168  case AV_CODEC_ID_VP9: maxpixels /= 4096; break;
169  }
170 
171 
173  AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
174  if (!ctx || !parser_avctx)
175  error("Failed memory allocation");
176 
177  if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
178  ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
179  ctx->refcounted_frames = 1; //To reduce false positive timeouts and focus testing on the refcounted API
180 
182 
183  if (size > 1024) {
184  GetByteContext gbc;
185  int extradata_size;
186  int flags;
187  size -= 1024;
188  bytestream2_init(&gbc, data + size, 1024);
189  ctx->width = bytestream2_get_le32(&gbc);
190  ctx->height = bytestream2_get_le32(&gbc);
191  ctx->bit_rate = bytestream2_get_le64(&gbc);
192  ctx->bits_per_coded_sample = bytestream2_get_le32(&gbc);
193  // Try to initialize a parser for this codec, note, this may fail which just means we test without one
194  flags = bytestream2_get_byte(&gbc);
195  if (flags & 1)
196  parser = av_parser_init(c->id);
197  if (flags & 2)
199  if (flags & 4) {
201  if (flags & 8)
203  }
204  if (flags & 0x10)
205  ctx->flags2 |= AV_CODEC_FLAG2_FAST;
206 
207  if (flags & 0x40)
209 
210  extradata_size = bytestream2_get_le32(&gbc);
211 
212  ctx->sample_rate = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
213  ctx->channels = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
214  ctx->block_align = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
215  ctx->codec_tag = bytestream2_get_le32(&gbc);
216  if (c->codec_tags) {
217  int n;
218  for (n = 0; c->codec_tags[n] != FF_CODEC_TAGS_END; n++);
219  ctx->codec_tag = c->codec_tags[ctx->codec_tag % n];
220  }
221  keyframes = bytestream2_get_le64(&gbc);
222  ctx->request_channel_layout = bytestream2_get_le64(&gbc);
223 
224  ctx->idct_algo = bytestream2_get_byte(&gbc) % 25;
225 
226  if (flags & 0x20) {
227  switch (ctx->codec_id) {
228  case AV_CODEC_ID_AC3:
229  case AV_CODEC_ID_EAC3:
230  av_dict_set_int(&opts, "cons_noisegen", bytestream2_get_byte(&gbc) & 1, 0);
231  av_dict_set_int(&opts, "heavy_compr", bytestream2_get_byte(&gbc) & 1, 0);
232  av_dict_set_int(&opts, "target_level", (int)(bytestream2_get_byte(&gbc) % 32) - 31, 0);
233  av_dict_set_int(&opts, "dmix_mode", (int)(bytestream2_get_byte(&gbc) % 4) - 1, 0);
234  break;
235  }
236  }
237 
238 
239  if (extradata_size < size) {
240  ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
241  if (ctx->extradata) {
242  ctx->extradata_size = extradata_size;
243  size -= ctx->extradata_size;
244  memcpy(ctx->extradata, data + size, ctx->extradata_size);
245  }
246  }
247  if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
248  ctx->width = ctx->height = 0;
249  }
250 
251  int res = avcodec_open2(ctx, c, &opts);
252  if (res < 0) {
253  avcodec_free_context(&ctx);
254  av_free(parser_avctx);
255  av_parser_close(parser);
256  av_dict_free(&opts);
257  return 0; // Failure of avcodec_open2() does not imply that a issue was found
258  }
259  parser_avctx->codec_id = ctx->codec_id;
260 
261  int got_frame;
263  if (!frame)
264  error("Failed memory allocation");
265 
266  // Read very simple container
267  AVPacket avpkt, parsepkt;
268  av_init_packet(&avpkt);
269  av_init_packet(&parsepkt);
270  while (data < end && it < maxiteration) {
271  // Search for the TAG
272  while (data + sizeof(fuzz_tag) < end) {
273  if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
274  break;
275  data++;
276  }
277  if (data + sizeof(fuzz_tag) > end)
278  data = end;
279 
280  res = av_new_packet(&parsepkt, data - last);
281  if (res < 0)
282  error("Failed memory allocation");
283  memcpy(parsepkt.data, last, data - last);
284  parsepkt.flags = (keyframes & 1) * AV_PKT_FLAG_DISCARD + (!!(keyframes & 2)) * AV_PKT_FLAG_KEY;
285  keyframes = (keyframes >> 2) + (keyframes<<62);
286  data += sizeof(fuzz_tag);
287  last = data;
288 
289  while (parsepkt.size > 0) {
290 
291  if (parser) {
292  av_init_packet(&avpkt);
293  int ret = av_parser_parse2(parser, parser_avctx, &avpkt.data, &avpkt.size,
294  parsepkt.data, parsepkt.size,
295  parsepkt.pts, parsepkt.dts, parsepkt.pos);
296  if (avpkt.data == parsepkt.data) {
297  avpkt.buf = av_buffer_ref(parsepkt.buf);
298  if (!avpkt.buf)
299  error("Failed memory allocation");
300  } else {
301  if (av_packet_make_refcounted(&avpkt) < 0)
302  error("Failed memory allocation");
303  }
304  parsepkt.data += ret;
305  parsepkt.size -= ret;
306  parsepkt.pos += ret;
307  avpkt.pts = parser->pts;
308  avpkt.dts = parser->dts;
309  avpkt.pos = parser->pos;
310  if ( parser->key_frame == 1 ||
311  (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
312  avpkt.flags |= AV_PKT_FLAG_KEY;
313  avpkt.flags |= parsepkt.flags & AV_PKT_FLAG_DISCARD;
314  } else {
315  av_packet_move_ref(&avpkt, &parsepkt);
316  }
317 
318  // Iterate through all data
319  while (avpkt.size > 0 && it++ < maxiteration) {
320  av_frame_unref(frame);
321  int ret = decode_handler(ctx, frame, &got_frame, &avpkt);
322 
323  ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
324  if (it > 20 || ec_pixels > 4 * ctx->max_pixels)
325  ctx->error_concealment = 0;
326  if (ec_pixels > maxpixels)
327  goto maximums_reached;
328 
329  nb_samples += frame->nb_samples;
330  if (nb_samples > maxsamples)
331  goto maximums_reached;
332 
333  if (ret <= 0 || ret > avpkt.size)
334  break;
335  if (ctx->codec_type != AVMEDIA_TYPE_AUDIO)
336  ret = avpkt.size;
337  avpkt.data += ret;
338  avpkt.size -= ret;
339  }
340  av_packet_unref(&avpkt);
341  }
342  av_packet_unref(&parsepkt);
343  }
344 maximums_reached:
345 
346  av_packet_unref(&avpkt);
347 
348  do {
349  got_frame = 0;
350  av_frame_unref(frame);
351  decode_handler(ctx, frame, &got_frame, &avpkt);
352  } while (got_frame == 1 && it++ < maxiteration);
353 
354  fprintf(stderr, "pixels decoded: %"PRId64", samples decoded: %"PRId64", iterations: %d\n", ec_pixels, nb_samples, it);
355 
356  av_frame_free(&frame);
357  avcodec_free_context(&ctx);
358  avcodec_free_context(&parser_avctx);
359  av_parser_close(parser);
360  av_packet_unref(&parsepkt);
361  av_dict_free(&opts);
362  return 0;
363 }
#define FF_SANE_NB_CHANNELS
Definition: internal.h:92
#define FF_COMPLIANCE_EXPERIMENTAL
Allow nonstandardized experimental things.
Definition: avcodec.h:2649
const uint32_t maxiteration
#define AV_EF_AGGRESSIVE
consider things that a sane encoder should not do as an error
Definition: avcodec.h:2726
#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:1631
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1513
void av_log_set_level(int level)
Set the log level.
Definition: log.c:387
int size
Definition: avcodec.h:1494
#define AV_EF_COMPLIANT
consider all spec non compliances as errors
Definition: avcodec.h:2725
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:3518
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:3505
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2278
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:1682
uint8_t * data
Definition: avcodec.h:1493
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:842
ptrdiff_t size
Definition: opengl_enc.c:100
const uint32_t * codec_tags
List of supported codec_tags, terminated by FF_CODEC_TAGS_END.
Definition: avcodec.h:3651
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2805
void avcodec_register_all(void)
Register all the codecs, parsers and bitstream filters which were enabled at configuration time...
Definition: allcodecs.c:857
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1525
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:3519
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:5247
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:2656
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:203
AVBufferRef * buf
A reference to the reference-counted buffer where the packet data is stored.
Definition: avcodec.h:1476
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:3308
const uint64_t maxpixels_per_frame
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1499
AVDictionary * opts
Definition: movenc.c:50
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
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:2710
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:1754
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
Definition: avcodec.h:2784
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
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: avcodec.h:2721
int n
Definition: avisynth_c.h:760
enum AVCodecID codec_id
Definition: vaapi_decode.c:364
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:1589
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:1591
int sample_rate
samples per second
Definition: avcodec.h:2241
#define AV_CODEC_FLAG2_FAST
Allow non spec compliant speedup tricks.
Definition: avcodec.h:929
main external API structure.
Definition: avcodec.h:1581
AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:899
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:1084
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:1606
int64_t max_samples
The number of samples per frame to maximally accept.
Definition: avcodec.h:3396
int extradata_size
Definition: avcodec.h:1683
#define AV_EF_CAREFUL
consider things that violate the spec, are fast to calculate and have not been seen in the wild as er...
Definition: avcodec.h:2724
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:2412
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:564
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:1532
common internal api header.
int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags)
Convenience wrapper for av_dict_set that converts the value to a string and stores it...
Definition: dict.c:147
AVBufferRef * av_buffer_ref(AVBufferRef *buf)
Create a new reference to an AVBuffer.
Definition: buffer.c:94
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:796
#define av_free(p)
uint64_t maxpixels
int channels
number of audio channels
Definition: avcodec.h:2242
#define AV_RN64(p)
Definition: intreadwrite.h:368
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:1668
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1492
#define FF_CODEC_TAGS_END
AVCodec.codec_tags termination value.
Definition: internal.h:75
void av_force_cpu_flags(int arg)
Disables cpu detection and forces the specified flags.
Definition: cpu.c:65
uint64_t request_channel_layout
Request decoder to use this channel layout if it can (0 for default)
Definition: avcodec.h:2299
This structure stores compressed data.
Definition: avcodec.h:1470
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:5186
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:2644
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1486
AVCodec * codec_list[]
const uint64_t maxsamples_per_frame