tools/target_dec_fuzzer.c

   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 -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,--as-needed -Wl,-z,noexecstack -Wl,--warn-common -Wl,-rpath-link=:libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil -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/avstring.h"
  51 #include "libavutil/cpu.h"
  52 #include "libavutil/imgutils.h"
  53 #include "libavutil/intreadwrite.h"
  54
  55 #include "libavcodec/avcodec.h"
  56 #include "libavcodec/bytestream.h"
  57 #include "libavcodec/codec_internal.h"
  58 #include "libavformat/avformat.h"
  59
  60 //For FF_SANE_NB_CHANNELS, so we dont waste energy testing things that will get instantly rejected
  61 #include "libavcodec/internal.h"
  62
  63 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
  64
  65 extern const FFCodec * codec_list[];
  66
  67 static void error(const char *err)
  68 {
  69     fprintf(stderr, "%s", err);
  70     exit(1);
  71 }
  72
  73 static const FFCodec *c = NULL;
  74 static const FFCodec *AVCodecInitialize(enum AVCodecID codec_id)
  75 {
  76     const AVCodec *res;
  77
  78     res = avcodec_find_decoder(codec_id);
  79     if (!res)
  80         error("Failed to find decoder");
  81     return ffcodec(res);
  82 }
  83
  84 static int subtitle_handler(AVCodecContext *avctx, void *frame,
  85                             int *got_sub_ptr, AVPacket *avpkt)
  86 {
  87     AVSubtitle sub;
  88     int ret = avcodec_decode_subtitle2(avctx, &sub, got_sub_ptr, avpkt);
  89     if (ret >= 0 && *got_sub_ptr)
  90         avsubtitle_free(&sub);
  91     return ret;
  92 }
  93
  94 static int audio_video_handler(AVCodecContext *avctx, AVFrame *frame,
  95                                int *got_frame, const AVPacket *dummy)
  96 {
  97     int ret = avcodec_receive_frame(avctx, frame);
  98     *got_frame = ret >= 0;
  99     return ret;
 100 }
 101
 102 // Ensure we don't loop forever
 103 const uint32_t maxiteration = 8096;
 104
 105 static const uint64_t FUZZ_TAG = 0x4741542D5A5A5546ULL;
 106
 107 static int fuzz_video_get_buffer(AVCodecContext *ctx, AVFrame *frame)
 108 {
 109     ptrdiff_t linesize1[4];
 110     size_t size[4];
 111     int linesize_align[AV_NUM_DATA_POINTERS];
 112     int i, ret, w = frame->width, h = frame->height;
 113
 114     avcodec_align_dimensions2(ctx, &w, &h, linesize_align);
 115     ret = av_image_fill_linesizes(frame->linesize, ctx->pix_fmt, w);
 116     if (ret < 0)
 117         return ret;
 118
 119     for (i = 0; i < 4 && frame->linesize[i]; i++)
 120         linesize1[i] = frame->linesize[i] =
 121             FFALIGN(frame->linesize[i], linesize_align[i]);
 122     for (; i < 4; i++)
 123         linesize1[i] = 0;
 124
 125     ret = av_image_fill_plane_sizes(size, ctx->pix_fmt, h, linesize1);
 126     if (ret < 0)
 127         return ret;
 128
 129     frame->extended_data = frame->data;
 130     for (i = 0; i < 4 && size[i]; i++) {
 131         switch(ctx->codec_id) {
 132         case AV_CODEC_ID_FFV1:
 133             frame->buf[i] = av_buffer_alloc(size[i]);
 134         break;
 135         default:
 136             frame->buf[i] = av_buffer_allocz(size[i]);
 137         }
 138
 139         if (!frame->buf[i])
 140             goto fail;
 141         frame->data[i] = frame->buf[i]->data;
 142     }
 143     for (; i < AV_NUM_DATA_POINTERS; i++) {
 144         frame->data[i] = NULL;
 145         frame->linesize[i] = 0;
 146     }
 147
 148     return 0;
 149 fail:
 150     av_frame_unref(frame);
 151     return AVERROR(ENOMEM);
 152 }
 153
 154 static int fuzz_get_buffer2(AVCodecContext *ctx, AVFrame *frame, int flags)
 155 {
 156     switch (ctx->codec_type) {
 157     case AVMEDIA_TYPE_VIDEO:
 158         return (ctx->codec->capabilities & AV_CODEC_CAP_DR1)
 159                ? fuzz_video_get_buffer(ctx, frame)
 160                : avcodec_default_get_buffer2(ctx, frame, flags);
 161     case AVMEDIA_TYPE_AUDIO:
 162         return avcodec_default_get_buffer2(ctx, frame, flags);
 163     default:
 164         return AVERROR(EINVAL);
 165     }
 166 }
 167
 168 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
 169     uint64_t maxpixels_per_frame = 4096 * 4096;
 170     uint64_t maxpixels;
 171
 172     uint64_t maxsamples_per_frame = 256*1024*32;
 173     uint64_t maxsamples;
 174     const uint64_t fuzz_tag = FUZZ_TAG;
 175     const uint8_t *last = data;
 176     const uint8_t *end = data + size;
 177     uint32_t it = 0;
 178     uint64_t ec_pixels = 0;
 179     uint64_t nb_samples = 0;
 180     int (*decode_handler)(AVCodecContext *avctx, AVFrame *picture,
 181                           int *got_picture_ptr,
 182                           const AVPacket *avpkt) = NULL;
 183     AVCodecParserContext *parser = NULL;
 184     uint64_t keyframes = 0;
 185     uint64_t flushpattern = -1;
 186     AVDictionary *opts = NULL;
 187
 188     if (!c) {
 189 #ifdef FFMPEG_DECODER
 190 #define DECODER_SYMBOL0(CODEC) ff_##CODEC##_decoder
 191 #define DECODER_SYMBOL(CODEC) DECODER_SYMBOL0(CODEC)
 192         extern FFCodec DECODER_SYMBOL(FFMPEG_DECODER);
 193         codec_list[0] = &DECODER_SYMBOL(FFMPEG_DECODER);
 194
 195 #if FFMPEG_DECODER == tiff || FFMPEG_DECODER == tdsc
 196         extern FFCodec DECODER_SYMBOL(mjpeg);
 197         codec_list[1] = &DECODER_SYMBOL(mjpeg);
 198 #endif
 199
 200         c = &DECODER_SYMBOL(FFMPEG_DECODER);
 201 #else
 202         c = AVCodecInitialize(FFMPEG_CODEC);  // Done once.
 203 #endif
 204         av_log_set_level(AV_LOG_PANIC);
 205     }
 206
 207     switch (c->p.type) {
 208     case AVMEDIA_TYPE_AUDIO   :
 209     case AVMEDIA_TYPE_VIDEO   : decode_handler = audio_video_handler  ; break;
 210     case AVMEDIA_TYPE_SUBTITLE: decode_handler = subtitle_handler     ; break;
 211     }
 212     switch (c->p.id) {
 213     case AV_CODEC_ID_APE:       maxsamples_per_frame /= 256; break;
 214     }
 215     maxpixels = maxpixels_per_frame * maxiteration;
 216     maxsamples = maxsamples_per_frame * maxiteration;
 217     switch (c->p.id) {
 218     case AV_CODEC_ID_AASC:        maxpixels  /= 1024;  break;
 219     case AV_CODEC_ID_AGM:         maxpixels  /= 1024;  break;
 220     case AV_CODEC_ID_ANM:         maxpixels  /= 1024;  break;
 221     case AV_CODEC_ID_ARBC:        maxpixels  /= 1024;  break;
 222     case AV_CODEC_ID_ARGO:        maxpixels  /= 1024;  break;
 223     case AV_CODEC_ID_BINKVIDEO:   maxpixels  /= 32;    break;
 224     case AV_CODEC_ID_CDTOONS:     maxpixels  /= 1024;  break;
 225     case AV_CODEC_ID_CFHD:        maxpixels  /= 16384; break;
 226     case AV_CODEC_ID_CINEPAK:     maxpixels  /= 128;   break;
 227     case AV_CODEC_ID_COOK:        maxsamples /= 1<<20; break;
 228     case AV_CODEC_ID_CSCD:        maxpixels  /= 1024;  break;
 229     case AV_CODEC_ID_DFA:         maxpixels  /= 1024;  break;
 230     case AV_CODEC_ID_DIRAC:       maxpixels  /= 8192;  break;
 231     case AV_CODEC_ID_DSICINVIDEO: maxpixels  /= 1024;  break;
 232     case AV_CODEC_ID_DST:         maxsamples /= 1<<20; break;
 233     case AV_CODEC_ID_DVB_SUBTITLE: av_dict_set_int(&opts, "compute_clut", -2, 0); break;
 234     case AV_CODEC_ID_DXA:         maxpixels  /= 32;    break;
 235     case AV_CODEC_ID_DXV:         maxpixels  /= 32;    break;
 236     case AV_CODEC_ID_FFWAVESYNTH: maxsamples /= 16384; break;
 237     case AV_CODEC_ID_FLAC:        maxsamples /= 1024;  break;
 238     case AV_CODEC_ID_FLIC:        maxpixels  /= 1024;  break;
 239     case AV_CODEC_ID_FLV1:        maxpixels  /= 1024;  break;
 240     case AV_CODEC_ID_G2M:         maxpixels  /= 1024;  break;
 241     case AV_CODEC_ID_GEM:         maxpixels  /= 512;   break;
 242     case AV_CODEC_ID_GDV:         maxpixels  /= 512;   break;
 243     case AV_CODEC_ID_GIF:         maxpixels  /= 16;    break;
 244     case AV_CODEC_ID_H264:        maxpixels  /= 256;   break;
 245     case AV_CODEC_ID_HAP:         maxpixels  /= 128;   break;
 246     case AV_CODEC_ID_HEVC:        maxpixels  /= 16384; break;
 247     case AV_CODEC_ID_HNM4_VIDEO:  maxpixels  /= 128;   break;
 248     case AV_CODEC_ID_HQ_HQA:      maxpixels  /= 128;   break;
 249     case AV_CODEC_ID_IFF_ILBM:    maxpixels  /= 128;   break;
 250     case AV_CODEC_ID_INDEO4:      maxpixels  /= 128;   break;
 251     case AV_CODEC_ID_INTERPLAY_ACM: maxsamples /= 16384;  break;
 252     case AV_CODEC_ID_JPEG2000:    maxpixels  /= 16;    break;
 253     case AV_CODEC_ID_LAGARITH:    maxpixels  /= 1024;  break;
 254     case AV_CODEC_ID_LOCO:        maxpixels  /= 1024;  break;
 255     case AV_CODEC_ID_VORBIS:      maxsamples /= 1024;  break;
 256     case AV_CODEC_ID_LSCR:        maxpixels  /= 16;    break;
 257     case AV_CODEC_ID_MMVIDEO:     maxpixels  /= 256;   break;
 258     case AV_CODEC_ID_MOTIONPIXELS:maxpixels  /= 256;   break;
 259     case AV_CODEC_ID_MP4ALS:      maxsamples /= 65536; break;
 260     case AV_CODEC_ID_MSA1:        maxpixels  /= 16384; break;
 261     case AV_CODEC_ID_MSRLE:       maxpixels  /= 16;    break;
 262     case AV_CODEC_ID_MSS2:        maxpixels  /= 16384; break;
 263     case AV_CODEC_ID_MSZH:        maxpixels  /= 128;   break;
 264     case AV_CODEC_ID_MVC2:        maxpixels  /= 128;   break;
 265     case AV_CODEC_ID_MXPEG:       maxpixels  /= 128;   break;
 266     case AV_CODEC_ID_OPUS:        maxsamples /= 16384; break;
 267     case AV_CODEC_ID_PNG:         maxpixels  /= 128;   break;
 268     case AV_CODEC_ID_APNG:        maxpixels  /= 128;   break;
 269     case AV_CODEC_ID_QTRLE:       maxpixels  /= 16;    break;
 270     case AV_CODEC_ID_PAF_VIDEO:   maxpixels  /= 16;    break;
 271     case AV_CODEC_ID_PRORES:      maxpixels  /= 256;   break;
 272     case AV_CODEC_ID_RASC:        maxpixels  /= 16;    break;
 273     case AV_CODEC_ID_RTV1:        maxpixels  /= 16;    break;
 274     case AV_CODEC_ID_SANM:        maxpixels  /= 16;    break;
 275     case AV_CODEC_ID_SCPR:        maxpixels  /= 32;    break;
 276     case AV_CODEC_ID_SCREENPRESSO:maxpixels  /= 64;    break;
 277     case AV_CODEC_ID_SIMBIOSIS_IMX:maxpixels /= 16384; break;
 278     case AV_CODEC_ID_SPEEX:       maxsamples /= 128;   break;
 279     case AV_CODEC_ID_SMACKAUDIO:  maxsamples /= 4096;  break;
 280     case AV_CODEC_ID_SMACKVIDEO:  maxpixels  /= 64;    break;
 281     case AV_CODEC_ID_SNOW:        maxpixels  /= 128;   break;
 282     case AV_CODEC_ID_TARGA:       maxpixels  /= 128;   break;
 283     case AV_CODEC_ID_TAK:         maxsamples /= 1024;  break;
 284     case AV_CODEC_ID_TGV:         maxpixels  /= 32;    break;
 285     case AV_CODEC_ID_THEORA:      maxpixels  /= 16384; break;
 286     case AV_CODEC_ID_TQI:         maxpixels  /= 1024;  break;
 287     case AV_CODEC_ID_TRUEMOTION2: maxpixels  /= 1024;  break;
 288     case AV_CODEC_ID_TSCC:        maxpixels  /= 1024;  break;
 289     case AV_CODEC_ID_VC1:         maxpixels  /= 8192;  break;
 290     case AV_CODEC_ID_VC1IMAGE:    maxpixels  /= 8192;  break;
 291     case AV_CODEC_ID_VMNC:        maxpixels  /= 8192;  break;
 292     case AV_CODEC_ID_VP3:         maxpixels  /= 4096;  break;
 293     case AV_CODEC_ID_VP4:         maxpixels  /= 4096;  break;
 294     case AV_CODEC_ID_VP5:         maxpixels  /= 256;   break;
 295     case AV_CODEC_ID_VP6F:        maxpixels  /= 4096;  break;
 296     case AV_CODEC_ID_VP7:         maxpixels  /= 256;   break;
 297     case AV_CODEC_ID_VP9:         maxpixels  /= 4096;  break;
 298     case AV_CODEC_ID_WAVPACK:     maxsamples /= 1024;  break;
 299     case AV_CODEC_ID_WCMV:        maxpixels  /= 1024;  break;
 300     case AV_CODEC_ID_WMV3IMAGE:   maxpixels  /= 8192;  break;
 301     case AV_CODEC_ID_WMV2:        maxpixels  /= 1024;  break;
 302     case AV_CODEC_ID_WMV3:        maxpixels  /= 1024;  break;
 303     case AV_CODEC_ID_WS_VQA:      maxpixels  /= 16384; break;
 304     case AV_CODEC_ID_WMALOSSLESS: maxsamples /= 1024;  break;
 305     case AV_CODEC_ID_WMAPRO:      maxsamples /= 16384; break;
 306     case AV_CODEC_ID_YLC:         maxpixels  /= 1024;  break;
 307     case AV_CODEC_ID_ZEROCODEC:   maxpixels  /= 128;   break;
 308     }
 309
 310     maxsamples_per_frame = FFMIN(maxsamples_per_frame, maxsamples);
 311     maxpixels_per_frame  = FFMIN(maxpixels_per_frame , maxpixels);
 312
 313     AVCodecContext* ctx = avcodec_alloc_context3(&c->p);
 314     AVCodecContext* parser_avctx = avcodec_alloc_context3(NULL);
 315     if (!ctx || !parser_avctx)
 316         error("Failed memory allocation");
 317
 318     if (ctx->max_pixels == 0 || ctx->max_pixels > maxpixels_per_frame)
 319         ctx->max_pixels = maxpixels_per_frame; //To reduce false positive OOM and hangs
 320
 321     ctx->max_samples = maxsamples_per_frame;
 322     ctx->get_buffer2 = fuzz_get_buffer2;
 323
 324     if (size > 1024) {
 325         GetByteContext gbc;
 326         int extradata_size;
 327         int flags;
 328         uint64_t request_channel_layout;
 329         int64_t flags64;
 330
 331         size -= 1024;
 332         bytestream2_init(&gbc, data + size, 1024);
 333         ctx->width                              = bytestream2_get_le32(&gbc);
 334         ctx->height                             = bytestream2_get_le32(&gbc);
 335         ctx->bit_rate                           = bytestream2_get_le64(&gbc);
 336         ctx->bits_per_coded_sample              = bytestream2_get_le32(&gbc);
 337         // Try to initialize a parser for this codec, note, this may fail which just means we test without one
 338         flags = bytestream2_get_byte(&gbc);
 339         if (flags & 1)
 340             parser = av_parser_init(c->p.id);
 341         if (flags & 2)
 342             ctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
 343         if (flags & 4) {
 344             ctx->err_recognition = AV_EF_AGGRESSIVE | AV_EF_COMPLIANT | AV_EF_CAREFUL;
 345             if (flags & 8)
 346                 ctx->err_recognition |= AV_EF_EXPLODE;
 347         }
 348         if ((flags & 0x10) && c->p.id != AV_CODEC_ID_H264)
 349             ctx->flags2 |= AV_CODEC_FLAG2_FAST;
 350         if (flags & 0x80)
 351             ctx->flags2 |= AV_CODEC_FLAG2_EXPORT_MVS;
 352
 353         if (flags & 0x40)
 354             av_force_cpu_flags(0);
 355
 356         extradata_size = bytestream2_get_le32(&gbc);
 357
 358         ctx->sample_rate                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
 359         ctx->ch_layout.nb_channels              = (unsigned)bytestream2_get_le32(&gbc) % FF_SANE_NB_CHANNELS;
 360         ctx->block_align                        = bytestream2_get_le32(&gbc) & 0x7FFFFFFF;
 361         ctx->codec_tag                          = bytestream2_get_le32(&gbc);
 362         if (c->codec_tags) {
 363             int n;
 364             for (n = 0; c->codec_tags[n] != FF_CODEC_TAGS_END; n++);
 365             ctx->codec_tag = c->codec_tags[ctx->codec_tag % n];
 366         }
 367         keyframes                               = bytestream2_get_le64(&gbc);
 368         request_channel_layout                  = bytestream2_get_le64(&gbc);
 369
 370         ctx->idct_algo                          = bytestream2_get_byte(&gbc) % 25;
 371         flushpattern                            = bytestream2_get_le64(&gbc);
 372         ctx->skip_frame                         = bytestream2_get_byte(&gbc) - 254 + AVDISCARD_ALL;
 373
 374
 375         if (flags & 0x20) {
 376             switch (ctx->codec_id) {
 377             case AV_CODEC_ID_AC3:
 378             case AV_CODEC_ID_EAC3:
 379                 av_dict_set_int(&opts, "cons_noisegen", bytestream2_get_byte(&gbc) & 1, 0);
 380                 av_dict_set_int(&opts, "heavy_compr",   bytestream2_get_byte(&gbc) & 1, 0);
 381                 av_dict_set_int(&opts, "target_level",  (int)(bytestream2_get_byte(&gbc) % 32) - 31, 0);
 382                 av_dict_set_int(&opts, "dmix_mode",     (int)(bytestream2_get_byte(&gbc) %  4) -  1, 0);
 383                 break;
 384             }
 385         }
 386
 387         // Keep the deprecated request_channel_layout behavior to ensure old fuzzing failures
 388         // remain reproducible.
 389         if (request_channel_layout) {
 390             switch (ctx->codec_id) {
 391             case AV_CODEC_ID_AC3:
 392             case AV_CODEC_ID_EAC3:
 393             case AV_CODEC_ID_MLP:
 394             case AV_CODEC_ID_TRUEHD:
 395             case AV_CODEC_ID_DTS:
 396                 if (request_channel_layout & ~INT64_MIN) {
 397                     char *downmix_layout = av_mallocz(19);
 398                     if (!downmix_layout)
 399                         error("Failed memory allocation");
 400                     av_strlcatf(downmix_layout, 19, "0x%"PRIx64, request_channel_layout & ~INT64_MIN);
 401                     av_dict_set(&opts, "downmix", downmix_layout, AV_DICT_DONT_STRDUP_VAL);
 402                 }
 403                 if (ctx->codec_id != AV_CODEC_ID_DTS)
 404                     break;
 405             // fall-through
 406             case AV_CODEC_ID_DOLBY_E:
 407                 av_dict_set_int(&opts, "channel_order", !!(request_channel_layout & INT64_MIN), 0);
 408                 break;
 409             }
 410         }
 411
 412         flags64 = bytestream2_get_le64(&gbc);
 413         if (flags64 &1)
 414             ctx->debug |= FF_DEBUG_SKIP;
 415         if (flags64 &2)
 416             ctx->debug |= FF_DEBUG_QP;
 417         if (flags64 &4)
 418             ctx->debug |= FF_DEBUG_MB_TYPE;
 419
 420         if (extradata_size < size) {
 421             ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
 422             if (ctx->extradata) {
 423                 ctx->extradata_size = extradata_size;
 424                 size -= ctx->extradata_size;
 425                 memcpy(ctx->extradata, data + size, ctx->extradata_size);
 426             }
 427         }
 428         if (av_image_check_size(ctx->width, ctx->height, 0, ctx))
 429             ctx->width = ctx->height = 0;
 430     }
 431
 432     int res = avcodec_open2(ctx, &c->p, &opts);
 433     if (res < 0) {
 434         avcodec_free_context(&ctx);
 435         av_free(parser_avctx);
 436         av_parser_close(parser);
 437         av_dict_free(&opts);
 438         return 0; // Failure of avcodec_open2() does not imply that a issue was found
 439     }
 440     parser_avctx->codec_id = ctx->codec_id;
 441     parser_avctx->extradata_size = ctx->extradata_size;
 442     parser_avctx->extradata      = ctx->extradata ? av_memdup(ctx->extradata, ctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE) : NULL;
 443
 444
 445     int got_frame;
 446     AVFrame *frame = av_frame_alloc();
 447     AVPacket *avpkt = av_packet_alloc();
 448     AVPacket *parsepkt = av_packet_alloc();
 449     if (!frame || !avpkt || !parsepkt)
 450         error("Failed memory allocation");
 451
 452     // Read very simple container
 453     while (data < end && it < maxiteration) {
 454         // Search for the TAG
 455         while (data + sizeof(fuzz_tag) < end) {
 456             if (data[0] == (fuzz_tag & 0xFF) && AV_RN64(data) == fuzz_tag)
 457                 break;
 458             data++;
 459         }
 460         if (data + sizeof(fuzz_tag) > end)
 461             data = end;
 462
 463         res = av_new_packet(parsepkt, data - last);
 464         if (res < 0)
 465             error("Failed memory allocation");
 466         memcpy(parsepkt->data, last, data - last);
 467         parsepkt->flags = (keyframes & 1) * AV_PKT_FLAG_DISCARD + (!!(keyframes & 2)) * AV_PKT_FLAG_KEY;
 468         keyframes = (keyframes >> 2) + (keyframes<<62);
 469         data += sizeof(fuzz_tag);
 470         last = data;
 471
 472         while (parsepkt->size > 0) {
 473             int decode_more;
 474
 475             if (parser) {
 476                 int ret = av_parser_parse2(parser, parser_avctx, &avpkt->data, &avpkt->size,
 477                                            parsepkt->data, parsepkt->size,
 478                                            parsepkt->pts, parsepkt->dts, parsepkt->pos);
 479                 if (avpkt->data == parsepkt->data) {
 480                     avpkt->buf = av_buffer_ref(parsepkt->buf);
 481                     if (!avpkt->buf)
 482                         error("Failed memory allocation");
 483                 } else {
 484                     if (av_packet_make_refcounted(avpkt) < 0)
 485                         error("Failed memory allocation");
 486                 }
 487                 parsepkt->data += ret;
 488                 parsepkt->size -= ret;
 489                 parsepkt->pos  += ret;
 490                 avpkt->pts = parser->pts;
 491                 avpkt->dts = parser->dts;
 492                 avpkt->pos = parser->pos;
 493                 if ( parser->key_frame == 1 ||
 494                     (parser->key_frame == -1 && parser->pict_type == AV_PICTURE_TYPE_I))
 495                     avpkt->flags |= AV_PKT_FLAG_KEY;
 496                 avpkt->flags |= parsepkt->flags & AV_PKT_FLAG_DISCARD;
 497             } else {
 498                 av_packet_move_ref(avpkt, parsepkt);
 499             }
 500
 501           if (!(flushpattern & 7))
 502               avcodec_flush_buffers(ctx);
 503           flushpattern = (flushpattern >> 3) + (flushpattern << 61);
 504
 505           if (ctx->codec_type != AVMEDIA_TYPE_SUBTITLE) {
 506               int ret = avcodec_send_packet(ctx, avpkt);
 507               decode_more = ret >= 0;
 508               if(!decode_more) {
 509                     ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
 510                     if (it > 20 || ec_pixels > 4 * ctx->max_pixels) {
 511                         ctx->error_concealment = 0;
 512                         ctx->debug &= ~(FF_DEBUG_SKIP | FF_DEBUG_QP | FF_DEBUG_MB_TYPE);
 513                     }
 514                     if (ec_pixels > maxpixels)
 515                         goto maximums_reached;
 516               }
 517           } else
 518               decode_more = 1;
 519
 520           // Iterate through all data
 521           while (decode_more && it++ < maxiteration) {
 522             av_frame_unref(frame);
 523             int ret = decode_handler(ctx, frame, &got_frame, avpkt);
 524
 525             ec_pixels += (ctx->width + 32LL) * (ctx->height + 32LL);
 526             if (it > 20 || ec_pixels > 4 * ctx->max_pixels) {
 527                 ctx->error_concealment = 0;
 528                 ctx->debug &= ~(FF_DEBUG_SKIP | FF_DEBUG_QP | FF_DEBUG_MB_TYPE);
 529             }
 530             if (ec_pixels > maxpixels)
 531                 goto maximums_reached;
 532
 533             if (ctx->codec_type == AVMEDIA_TYPE_AUDIO &&
 534                 frame->nb_samples == 0 && !got_frame &&
 535                 (avpkt->flags & AV_PKT_FLAG_DISCARD))
 536                 nb_samples += ctx->max_samples;
 537
 538             nb_samples += frame->nb_samples;
 539             if (nb_samples > maxsamples)
 540                 goto maximums_reached;
 541
 542             if (ret <= 0 || ret > avpkt->size)
 543                break;
 544
 545             if (ctx->codec_type == AVMEDIA_TYPE_SUBTITLE) {
 546                 avpkt->data += ret;
 547                 avpkt->size -= ret;
 548                 decode_more = avpkt->size > 0;
 549             } else
 550                 decode_more = ret >= 0;
 551           }
 552           av_packet_unref(avpkt);
 553         }
 554         av_packet_unref(parsepkt);
 555     }
 556 maximums_reached:
 557
 558     av_packet_unref(avpkt);
 559
 560     if (ctx->codec_type != AVMEDIA_TYPE_SUBTITLE)
 561         avcodec_send_packet(ctx, NULL);
 562
 563     do {
 564         got_frame = 0;
 565         av_frame_unref(frame);
 566         decode_handler(ctx, frame, &got_frame, avpkt);
 567
 568         nb_samples += frame->nb_samples;
 569         if (nb_samples > maxsamples)
 570             break;
 571     } while (got_frame == 1 && it++ < maxiteration);
 572
 573     fprintf(stderr, "pixels decoded: %"PRId64", samples decoded: %"PRId64", iterations: %d\n", ec_pixels, nb_samples, it);
 574
 575     av_frame_free(&frame);
 576     avcodec_free_context(&ctx);
 577     avcodec_free_context(&parser_avctx);
 578     av_parser_close(parser);
 579     av_packet_free(&avpkt);
 580     av_packet_free(&parsepkt);
 581     av_dict_free(&opts);
 582     return 0;
 583 }