media/ffmpeg/ffmpeg_common.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/ffmpeg/ffmpeg_common.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/logging.h"
   9 #include "base/metrics/histogram.h"
  10 #include "base/strings/string_number_conversions.h"
  11 #include "base/strings/string_split.h"
  12 #include "base/strings/string_util.h"
  13 #include "media/base/decoder_buffer.h"
  14 #include "media/base/video_util.h"
  15
  16 namespace media {
  17
  18 // Why FF_INPUT_BUFFER_PADDING_SIZE? FFmpeg assumes all input buffers are
  19 // padded. Check here to ensure FFmpeg only receives data padded to its
  20 // specifications.
  21 static_assert(DecoderBuffer::kPaddingSize >= FF_INPUT_BUFFER_PADDING_SIZE,
  22               "DecoderBuffer padding size does not fit ffmpeg requirement");
  23
  24 // Alignment requirement by FFmpeg for input and output buffers. This need to
  25 // be updated to match FFmpeg when it changes.
  26 #if defined(ARCH_CPU_ARM_FAMILY)
  27 static const int kFFmpegBufferAddressAlignment = 16;
  28 #else
  29 static const int kFFmpegBufferAddressAlignment = 32;
  30 #endif
  31
  32 // Check here to ensure FFmpeg only receives data aligned to its specifications.
  33 static_assert(
  34     DecoderBuffer::kAlignmentSize >= kFFmpegBufferAddressAlignment &&
  35     DecoderBuffer::kAlignmentSize % kFFmpegBufferAddressAlignment == 0,
  36     "DecoderBuffer alignment size does not fit ffmpeg requirement");
  37
  38 // Allows faster SIMD YUV convert. Also, FFmpeg overreads/-writes occasionally.
  39 // See video_get_buffer() in libavcodec/utils.c.
  40 static const int kFFmpegOutputBufferPaddingSize = 16;
  41
  42 static_assert(VideoFrame::kFrameSizePadding >= kFFmpegOutputBufferPaddingSize,
  43               "VideoFrame padding size does not fit ffmpeg requirement");
  44
  45 static_assert(
  46     VideoFrame::kFrameAddressAlignment >= kFFmpegBufferAddressAlignment &&
  47     VideoFrame::kFrameAddressAlignment % kFFmpegBufferAddressAlignment == 0,
  48     "VideoFrame frame address alignment does not fit ffmpeg requirement");
  49
  50 static const AVRational kMicrosBase = { 1, base::Time::kMicrosecondsPerSecond };
  51
  52 base::TimeDelta ConvertFromTimeBase(const AVRational& time_base,
  53                                     int64 timestamp) {
  54   int64 microseconds = av_rescale_q(timestamp, time_base, kMicrosBase);
  55   return base::TimeDelta::FromMicroseconds(microseconds);
  56 }
  57
  58 int64 ConvertToTimeBase(const AVRational& time_base,
  59                         const base::TimeDelta& timestamp) {
  60   return av_rescale_q(timestamp.InMicroseconds(), kMicrosBase, time_base);
  61 }
  62
  63 // Converts an FFmpeg audio codec ID into its corresponding supported codec id.
  64 static AudioCodec CodecIDToAudioCodec(AVCodecID codec_id) {
  65   switch (codec_id) {
  66     case AV_CODEC_ID_AAC:
  67       return kCodecAAC;
  68     case AV_CODEC_ID_MP3:
  69       return kCodecMP3;
  70     case AV_CODEC_ID_VORBIS:
  71       return kCodecVorbis;
  72     case AV_CODEC_ID_PCM_U8:
  73     case AV_CODEC_ID_PCM_S16LE:
  74     case AV_CODEC_ID_PCM_S24LE:
  75     case AV_CODEC_ID_PCM_F32LE:
  76       return kCodecPCM;
  77     case AV_CODEC_ID_PCM_S16BE:
  78       return kCodecPCM_S16BE;
  79     case AV_CODEC_ID_PCM_S24BE:
  80       return kCodecPCM_S24BE;
  81     case AV_CODEC_ID_FLAC:
  82       return kCodecFLAC;
  83     case AV_CODEC_ID_AMR_NB:
  84       return kCodecAMR_NB;
  85     case AV_CODEC_ID_AMR_WB:
  86       return kCodecAMR_WB;
  87     case AV_CODEC_ID_GSM_MS:
  88       return kCodecGSM_MS;
  89     case AV_CODEC_ID_PCM_ALAW:
  90       return kCodecPCM_ALAW;
  91     case AV_CODEC_ID_PCM_MULAW:
  92       return kCodecPCM_MULAW;
  93     case AV_CODEC_ID_OPUS:
  94       return kCodecOpus;
  95     case AV_CODEC_ID_ALAC:
  96       return kCodecALAC;
  97     default:
  98       DVLOG(1) << "Unknown audio CodecID: " << codec_id;
  99   }
 100   return kUnknownAudioCodec;
 101 }
 102
 103 static AVCodecID AudioCodecToCodecID(AudioCodec audio_codec,
 104                                      SampleFormat sample_format) {
 105   switch (audio_codec) {
 106     case kCodecAAC:
 107       return AV_CODEC_ID_AAC;
 108     case kCodecALAC:
 109       return AV_CODEC_ID_ALAC;
 110     case kCodecMP3:
 111       return AV_CODEC_ID_MP3;
 112     case kCodecPCM:
 113       switch (sample_format) {
 114         case kSampleFormatU8:
 115           return AV_CODEC_ID_PCM_U8;
 116         case kSampleFormatS16:
 117           return AV_CODEC_ID_PCM_S16LE;
 118         case kSampleFormatS32:
 119           return AV_CODEC_ID_PCM_S24LE;
 120         case kSampleFormatF32:
 121           return AV_CODEC_ID_PCM_F32LE;
 122         default:
 123           DVLOG(1) << "Unsupported sample format: " << sample_format;
 124       }
 125       break;
 126     case kCodecPCM_S16BE:
 127       return AV_CODEC_ID_PCM_S16BE;
 128     case kCodecPCM_S24BE:
 129       return AV_CODEC_ID_PCM_S24BE;
 130     case kCodecVorbis:
 131       return AV_CODEC_ID_VORBIS;
 132     case kCodecFLAC:
 133       return AV_CODEC_ID_FLAC;
 134     case kCodecAMR_NB:
 135       return AV_CODEC_ID_AMR_NB;
 136     case kCodecAMR_WB:
 137       return AV_CODEC_ID_AMR_WB;
 138     case kCodecGSM_MS:
 139       return AV_CODEC_ID_GSM_MS;
 140     case kCodecPCM_ALAW:
 141       return AV_CODEC_ID_PCM_ALAW;
 142     case kCodecPCM_MULAW:
 143       return AV_CODEC_ID_PCM_MULAW;
 144     case kCodecOpus:
 145       return AV_CODEC_ID_OPUS;
 146     default:
 147       DVLOG(1) << "Unknown AudioCodec: " << audio_codec;
 148   }
 149   return AV_CODEC_ID_NONE;
 150 }
 151
 152 // Converts an FFmpeg video codec ID into its corresponding supported codec id.
 153 static VideoCodec CodecIDToVideoCodec(AVCodecID codec_id) {
 154   switch (codec_id) {
 155     case AV_CODEC_ID_H264:
 156       return kCodecH264;
 157     case AV_CODEC_ID_THEORA:
 158       return kCodecTheora;
 159     case AV_CODEC_ID_MPEG4:
 160       return kCodecMPEG4;
 161     case AV_CODEC_ID_VP8:
 162       return kCodecVP8;
 163     case AV_CODEC_ID_VP9:
 164       return kCodecVP9;
 165     default:
 166       DVLOG(1) << "Unknown video CodecID: " << codec_id;
 167   }
 168   return kUnknownVideoCodec;
 169 }
 170
 171 static AVCodecID VideoCodecToCodecID(VideoCodec video_codec) {
 172   switch (video_codec) {
 173     case kCodecH264:
 174       return AV_CODEC_ID_H264;
 175     case kCodecTheora:
 176       return AV_CODEC_ID_THEORA;
 177     case kCodecMPEG4:
 178       return AV_CODEC_ID_MPEG4;
 179     case kCodecVP8:
 180       return AV_CODEC_ID_VP8;
 181     case kCodecVP9:
 182       return AV_CODEC_ID_VP9;
 183     default:
 184       DVLOG(1) << "Unknown VideoCodec: " << video_codec;
 185   }
 186   return AV_CODEC_ID_NONE;
 187 }
 188
 189 static VideoCodecProfile ProfileIDToVideoCodecProfile(int profile) {
 190   // Clear out the CONSTRAINED & INTRA flags which are strict subsets of the
 191   // corresponding profiles with which they're used.
 192   profile &= ~FF_PROFILE_H264_CONSTRAINED;
 193   profile &= ~FF_PROFILE_H264_INTRA;
 194   switch (profile) {
 195     case FF_PROFILE_H264_BASELINE:
 196       return H264PROFILE_BASELINE;
 197     case FF_PROFILE_H264_MAIN:
 198       return H264PROFILE_MAIN;
 199     case FF_PROFILE_H264_EXTENDED:
 200       return H264PROFILE_EXTENDED;
 201     case FF_PROFILE_H264_HIGH:
 202       return H264PROFILE_HIGH;
 203     case FF_PROFILE_H264_HIGH_10:
 204       return H264PROFILE_HIGH10PROFILE;
 205     case FF_PROFILE_H264_HIGH_422:
 206       return H264PROFILE_HIGH422PROFILE;
 207     case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
 208       return H264PROFILE_HIGH444PREDICTIVEPROFILE;
 209     default:
 210       DVLOG(1) << "Unknown profile id: " << profile;
 211   }
 212   return VIDEO_CODEC_PROFILE_UNKNOWN;
 213 }
 214
 215 static int VideoCodecProfileToProfileID(VideoCodecProfile profile) {
 216   switch (profile) {
 217     case H264PROFILE_BASELINE:
 218       return FF_PROFILE_H264_BASELINE;
 219     case H264PROFILE_MAIN:
 220       return FF_PROFILE_H264_MAIN;
 221     case H264PROFILE_EXTENDED:
 222       return FF_PROFILE_H264_EXTENDED;
 223     case H264PROFILE_HIGH:
 224       return FF_PROFILE_H264_HIGH;
 225     case H264PROFILE_HIGH10PROFILE:
 226       return FF_PROFILE_H264_HIGH_10;
 227     case H264PROFILE_HIGH422PROFILE:
 228       return FF_PROFILE_H264_HIGH_422;
 229     case H264PROFILE_HIGH444PREDICTIVEPROFILE:
 230       return FF_PROFILE_H264_HIGH_444_PREDICTIVE;
 231     default:
 232       DVLOG(1) << "Unknown VideoCodecProfile: " << profile;
 233   }
 234   return FF_PROFILE_UNKNOWN;
 235 }
 236
 237 SampleFormat AVSampleFormatToSampleFormat(AVSampleFormat sample_format) {
 238   switch (sample_format) {
 239     case AV_SAMPLE_FMT_U8:
 240       return kSampleFormatU8;
 241     case AV_SAMPLE_FMT_S16:
 242       return kSampleFormatS16;
 243     case AV_SAMPLE_FMT_S32:
 244       return kSampleFormatS32;
 245     case AV_SAMPLE_FMT_FLT:
 246       return kSampleFormatF32;
 247     case AV_SAMPLE_FMT_S16P:
 248       return kSampleFormatPlanarS16;
 249     case  AV_SAMPLE_FMT_S32P:
 250       return kSampleFormatPlanarS32;
 251     case AV_SAMPLE_FMT_FLTP:
 252       return kSampleFormatPlanarF32;
 253     default:
 254       DVLOG(1) << "Unknown AVSampleFormat: " << sample_format;
 255   }
 256   return kUnknownSampleFormat;
 257 }
 258
 259 static AVSampleFormat SampleFormatToAVSampleFormat(SampleFormat sample_format) {
 260   switch (sample_format) {
 261     case kSampleFormatU8:
 262       return AV_SAMPLE_FMT_U8;
 263     case kSampleFormatS16:
 264       return AV_SAMPLE_FMT_S16;
 265     case kSampleFormatS32:
 266       return AV_SAMPLE_FMT_S32;
 267     case kSampleFormatF32:
 268       return AV_SAMPLE_FMT_FLT;
 269     case kSampleFormatPlanarS16:
 270       return AV_SAMPLE_FMT_S16P;
 271     case kSampleFormatPlanarF32:
 272       return AV_SAMPLE_FMT_FLTP;
 273     default:
 274       DVLOG(1) << "Unknown SampleFormat: " << sample_format;
 275   }
 276   return AV_SAMPLE_FMT_NONE;
 277 }
 278
 279 void AVCodecContextToAudioDecoderConfig(
 280     const AVCodecContext* codec_context,
 281     bool is_encrypted,
 282     AudioDecoderConfig* config,
 283     bool record_stats) {
 284   DCHECK_EQ(codec_context->codec_type, AVMEDIA_TYPE_AUDIO);
 285
 286   AudioCodec codec = CodecIDToAudioCodec(codec_context->codec_id);
 287
 288   SampleFormat sample_format =
 289       AVSampleFormatToSampleFormat(codec_context->sample_fmt);
 290
 291   ChannelLayout channel_layout = ChannelLayoutToChromeChannelLayout(
 292       codec_context->channel_layout, codec_context->channels);
 293
 294   int sample_rate = codec_context->sample_rate;
 295   if (codec == kCodecOpus) {
 296     // |codec_context->sample_fmt| is not set by FFmpeg because Opus decoding is
 297     // not enabled in FFmpeg.  It doesn't matter what value is set here, so long
 298     // as it's valid, the true sample format is selected inside the decoder.
 299     sample_format = kSampleFormatF32;
 300
 301     // Always use 48kHz for OPUS.  Technically we should match to the highest
 302     // supported hardware sample rate among [8, 12, 16, 24, 48] kHz, but we
 303     // don't know the hardware sample rate at this point and those rates are
 304     // rarely used for output.  See the "Input Sample Rate" section of the spec:
 305     // http://tools.ietf.org/html/draft-terriberry-oggopus-01#page-11
 306     sample_rate = 48000;
 307   }
 308
 309   base::TimeDelta seek_preroll;
 310   if (codec_context->seek_preroll > 0) {
 311     seek_preroll = base::TimeDelta::FromMicroseconds(
 312         codec_context->seek_preroll * 1000000.0 / codec_context->sample_rate);
 313   }
 314
 315   config->Initialize(codec,
 316                      sample_format,
 317                      channel_layout,
 318                      sample_rate,
 319                      codec_context->extradata,
 320                      codec_context->extradata_size,
 321                      is_encrypted,
 322                      record_stats,
 323                      seek_preroll,
 324                      codec_context->delay);
 325   if (codec != kCodecOpus) {
 326     DCHECK_EQ(av_get_bytes_per_sample(codec_context->sample_fmt) * 8,
 327               config->bits_per_channel());
 328   }
 329 }
 330
 331 void AVStreamToAudioDecoderConfig(
 332     const AVStream* stream,
 333     AudioDecoderConfig* config,
 334     bool record_stats) {
 335   bool is_encrypted = false;
 336   AVDictionaryEntry* key = av_dict_get(stream->metadata, "enc_key_id", NULL, 0);
 337   if (key)
 338     is_encrypted = true;
 339   return AVCodecContextToAudioDecoderConfig(
 340       stream->codec, is_encrypted, config, record_stats);
 341 }
 342
 343 void AudioDecoderConfigToAVCodecContext(const AudioDecoderConfig& config,
 344                                         AVCodecContext* codec_context) {
 345   codec_context->codec_type = AVMEDIA_TYPE_AUDIO;
 346   codec_context->codec_id = AudioCodecToCodecID(config.codec(),
 347                                                 config.sample_format());
 348   codec_context->sample_fmt = SampleFormatToAVSampleFormat(
 349       config.sample_format());
 350
 351   // TODO(scherkus): should we set |channel_layout|? I'm not sure if FFmpeg uses
 352   // said information to decode.
 353   codec_context->channels =
 354       ChannelLayoutToChannelCount(config.channel_layout());
 355   codec_context->sample_rate = config.samples_per_second();
 356
 357   if (config.extra_data()) {
 358     codec_context->extradata_size = config.extra_data_size();
 359     codec_context->extradata = reinterpret_cast<uint8_t*>(
 360         av_malloc(config.extra_data_size() + FF_INPUT_BUFFER_PADDING_SIZE));
 361     memcpy(codec_context->extradata, config.extra_data(),
 362            config.extra_data_size());
 363     memset(codec_context->extradata + config.extra_data_size(), '\0',
 364            FF_INPUT_BUFFER_PADDING_SIZE);
 365   } else {
 366     codec_context->extradata = NULL;
 367     codec_context->extradata_size = 0;
 368   }
 369 }
 370
 371 void AVStreamToVideoDecoderConfig(
 372     const AVStream* stream,
 373     VideoDecoderConfig* config,
 374     bool record_stats) {
 375   gfx::Size coded_size(stream->codec->coded_width, stream->codec->coded_height);
 376
 377   // TODO(vrk): This assumes decoded frame data starts at (0, 0), which is true
 378   // for now, but may not always be true forever. Fix this in the future.
 379   gfx::Rect visible_rect(stream->codec->width, stream->codec->height);
 380
 381   AVRational aspect_ratio = { 1, 1 };
 382   if (stream->sample_aspect_ratio.num)
 383     aspect_ratio = stream->sample_aspect_ratio;
 384   else if (stream->codec->sample_aspect_ratio.num)
 385     aspect_ratio = stream->codec->sample_aspect_ratio;
 386
 387   VideoCodec codec = CodecIDToVideoCodec(stream->codec->codec_id);
 388
 389   VideoCodecProfile profile = VIDEO_CODEC_PROFILE_UNKNOWN;
 390   if (codec == kCodecVP8)
 391     profile = VP8PROFILE_ANY;
 392   else if (codec == kCodecVP9)
 393     profile = VP9PROFILE_ANY;
 394   else
 395     profile = ProfileIDToVideoCodecProfile(stream->codec->profile);
 396
 397   gfx::Size natural_size = GetNaturalSize(
 398       visible_rect.size(), aspect_ratio.num, aspect_ratio.den);
 399
 400   if (record_stats) {
 401     // Note the PRESUBMIT_IGNORE_UMA_MAX below, this silences the PRESUBMIT.py
 402     // check for uma enum max usage, since we're abusing
 403     // UMA_HISTOGRAM_ENUMERATION to report a discrete value.
 404     UMA_HISTOGRAM_ENUMERATION("Media.VideoColorRange",
 405                               stream->codec->color_range,
 406                               AVCOL_RANGE_NB);  // PRESUBMIT_IGNORE_UMA_MAX
 407   }
 408
 409   VideoPixelFormat format =
 410       PixelFormatToVideoPixelFormat(stream->codec->pix_fmt);
 411   if (codec == kCodecVP9) {
 412     // TODO(tomfinegan): libavcodec doesn't know about VP9.
 413     format = PIXEL_FORMAT_YV12;
 414     coded_size = visible_rect.size();
 415   }
 416
 417   // Pad out |coded_size| for subsampled YUV formats.
 418   if (format != PIXEL_FORMAT_YV24) {
 419     coded_size.set_width((coded_size.width() + 1) / 2 * 2);
 420     if (format != PIXEL_FORMAT_YV16)
 421       coded_size.set_height((coded_size.height() + 1) / 2 * 2);
 422   }
 423
 424   bool is_encrypted = false;
 425   AVDictionaryEntry* key = av_dict_get(stream->metadata, "enc_key_id", NULL, 0);
 426   if (key)
 427     is_encrypted = true;
 428
 429   AVDictionaryEntry* webm_alpha =
 430       av_dict_get(stream->metadata, "alpha_mode", NULL, 0);
 431   if (webm_alpha && !strcmp(webm_alpha->value, "1")) {
 432     format = PIXEL_FORMAT_YV12A;
 433   }
 434
 435   // Prefer the color space found by libavcodec if available.
 436   ColorSpace color_space = AVColorSpaceToColorSpace(stream->codec->colorspace);
 437   if (color_space == COLOR_SPACE_UNSPECIFIED) {
 438     // Otherwise, assume that SD video is usually Rec.601, and HD is usually
 439     // Rec.709.
 440     color_space = (natural_size.height() < 720) ? COLOR_SPACE_SD_REC601
 441                                                 : COLOR_SPACE_HD_REC709;
 442   }
 443
 444   config->Initialize(codec, profile, format, color_space, coded_size,
 445                      visible_rect, natural_size, stream->codec->extradata,
 446                      stream->codec->extradata_size, is_encrypted, record_stats);
 447 }
 448
 449 void VideoDecoderConfigToAVCodecContext(
 450     const VideoDecoderConfig& config,
 451     AVCodecContext* codec_context) {
 452   codec_context->codec_type = AVMEDIA_TYPE_VIDEO;
 453   codec_context->codec_id = VideoCodecToCodecID(config.codec());
 454   codec_context->profile = VideoCodecProfileToProfileID(config.profile());
 455   codec_context->coded_width = config.coded_size().width();
 456   codec_context->coded_height = config.coded_size().height();
 457   codec_context->pix_fmt = VideoPixelFormatToPixelFormat(config.format());
 458
 459   if (config.extra_data()) {
 460     codec_context->extradata_size = config.extra_data_size();
 461     codec_context->extradata = reinterpret_cast<uint8_t*>(
 462         av_malloc(config.extra_data_size() + FF_INPUT_BUFFER_PADDING_SIZE));
 463     memcpy(codec_context->extradata, config.extra_data(),
 464            config.extra_data_size());
 465     memset(codec_context->extradata + config.extra_data_size(), '\0',
 466            FF_INPUT_BUFFER_PADDING_SIZE);
 467   } else {
 468     codec_context->extradata = NULL;
 469     codec_context->extradata_size = 0;
 470   }
 471 }
 472
 473 ChannelLayout ChannelLayoutToChromeChannelLayout(int64_t layout, int channels) {
 474   switch (layout) {
 475     case AV_CH_LAYOUT_MONO:
 476       return CHANNEL_LAYOUT_MONO;
 477     case AV_CH_LAYOUT_STEREO:
 478       return CHANNEL_LAYOUT_STEREO;
 479     case AV_CH_LAYOUT_2_1:
 480       return CHANNEL_LAYOUT_2_1;
 481     case AV_CH_LAYOUT_SURROUND:
 482       return CHANNEL_LAYOUT_SURROUND;
 483     case AV_CH_LAYOUT_4POINT0:
 484       return CHANNEL_LAYOUT_4_0;
 485     case AV_CH_LAYOUT_2_2:
 486       return CHANNEL_LAYOUT_2_2;
 487     case AV_CH_LAYOUT_QUAD:
 488       return CHANNEL_LAYOUT_QUAD;
 489     case AV_CH_LAYOUT_5POINT0:
 490       return CHANNEL_LAYOUT_5_0;
 491     case AV_CH_LAYOUT_5POINT1:
 492       return CHANNEL_LAYOUT_5_1;
 493     case AV_CH_LAYOUT_5POINT0_BACK:
 494       return CHANNEL_LAYOUT_5_0_BACK;
 495     case AV_CH_LAYOUT_5POINT1_BACK:
 496       return CHANNEL_LAYOUT_5_1_BACK;
 497     case AV_CH_LAYOUT_7POINT0:
 498       return CHANNEL_LAYOUT_7_0;
 499     case AV_CH_LAYOUT_7POINT1:
 500       return CHANNEL_LAYOUT_7_1;
 501     case AV_CH_LAYOUT_7POINT1_WIDE:
 502       return CHANNEL_LAYOUT_7_1_WIDE;
 503     case AV_CH_LAYOUT_STEREO_DOWNMIX:
 504       return CHANNEL_LAYOUT_STEREO_DOWNMIX;
 505     case AV_CH_LAYOUT_2POINT1:
 506       return CHANNEL_LAYOUT_2POINT1;
 507     case AV_CH_LAYOUT_3POINT1:
 508       return CHANNEL_LAYOUT_3_1;
 509     case AV_CH_LAYOUT_4POINT1:
 510       return CHANNEL_LAYOUT_4_1;
 511     case AV_CH_LAYOUT_6POINT0:
 512       return CHANNEL_LAYOUT_6_0;
 513     case AV_CH_LAYOUT_6POINT0_FRONT:
 514       return CHANNEL_LAYOUT_6_0_FRONT;
 515     case AV_CH_LAYOUT_HEXAGONAL:
 516       return CHANNEL_LAYOUT_HEXAGONAL;
 517     case AV_CH_LAYOUT_6POINT1:
 518       return CHANNEL_LAYOUT_6_1;
 519     case AV_CH_LAYOUT_6POINT1_BACK:
 520       return CHANNEL_LAYOUT_6_1_BACK;
 521     case AV_CH_LAYOUT_6POINT1_FRONT:
 522       return CHANNEL_LAYOUT_6_1_FRONT;
 523     case AV_CH_LAYOUT_7POINT0_FRONT:
 524       return CHANNEL_LAYOUT_7_0_FRONT;
 525 #ifdef AV_CH_LAYOUT_7POINT1_WIDE_BACK
 526     case AV_CH_LAYOUT_7POINT1_WIDE_BACK:
 527       return CHANNEL_LAYOUT_7_1_WIDE_BACK;
 528 #endif
 529     case AV_CH_LAYOUT_OCTAGONAL:
 530       return CHANNEL_LAYOUT_OCTAGONAL;
 531     default:
 532       // FFmpeg channel_layout is 0 for .wav and .mp3.  Attempt to guess layout
 533       // based on the channel count.
 534       return GuessChannelLayout(channels);
 535   }
 536 }
 537
 538 VideoPixelFormat PixelFormatToVideoPixelFormat(PixelFormat pixel_format) {
 539   switch (pixel_format) {
 540     case PIX_FMT_YUV422P:
 541       return PIXEL_FORMAT_YV16;
 542     case PIX_FMT_YUV444P:
 543       return PIXEL_FORMAT_YV24;
 544     case PIX_FMT_YUV420P:
 545       return PIXEL_FORMAT_YV12;
 546     case PIX_FMT_YUVA420P:
 547       return PIXEL_FORMAT_YV12A;
 548     default:
 549       DVLOG(1) << "Unsupported PixelFormat: " << pixel_format;
 550   }
 551   return PIXEL_FORMAT_UNKNOWN;
 552 }
 553
 554 PixelFormat VideoPixelFormatToPixelFormat(VideoPixelFormat video_format) {
 555   switch (video_format) {
 556     case PIXEL_FORMAT_YV16:
 557       return PIX_FMT_YUV422P;
 558     case PIXEL_FORMAT_YV12:
 559       return PIX_FMT_YUV420P;
 560     case PIXEL_FORMAT_YV12A:
 561       return PIX_FMT_YUVA420P;
 562     case PIXEL_FORMAT_YV24:
 563       return PIX_FMT_YUV444P;
 564     default:
 565       DVLOG(1) << "Unsupported Format: " << video_format;
 566   }
 567   return PIX_FMT_NONE;
 568 }
 569
 570 ColorSpace AVColorSpaceToColorSpace(
 571     AVColorSpace color_space) {
 572   switch (color_space) {
 573     case AVCOL_SPC_UNSPECIFIED:
 574       break;
 575     case AVCOL_SPC_BT709:
 576       return COLOR_SPACE_HD_REC709;
 577     case AVCOL_SPC_SMPTE170M:
 578     case AVCOL_SPC_BT470BG:
 579       return COLOR_SPACE_SD_REC601;
 580     default:
 581       DVLOG(1) << "Unknown AVColorSpace: " << color_space;
 582   }
 583   return COLOR_SPACE_UNSPECIFIED;
 584 }
 585
 586 bool FFmpegUTCDateToTime(const char* date_utc, base::Time* out) {
 587   DCHECK(date_utc);
 588   DCHECK(out);
 589
 590   std::vector<base::StringPiece> fields = base::SplitStringPiece(
 591       date_utc, " ", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 592   if (fields.size() != 2)
 593     return false;
 594
 595   std::vector<base::StringPiece> date_fields = base::SplitStringPiece(
 596       fields[0], "-", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 597   if (date_fields.size() != 3)
 598     return false;
 599
 600   // TODO(acolwell): Update this parsing code when FFmpeg returns sub-second
 601   // information.
 602   std::vector<base::StringPiece> time_fields = base::SplitStringPiece(
 603       fields[1], ":", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
 604   if (time_fields.size() != 3)
 605     return false;
 606
 607   base::Time::Exploded exploded;
 608   exploded.millisecond = 0;
 609   if (base::StringToInt(date_fields[0], &exploded.year) &&
 610       base::StringToInt(date_fields[1], &exploded.month) &&
 611       base::StringToInt(date_fields[2], &exploded.day_of_month) &&
 612       base::StringToInt(time_fields[0], &exploded.hour) &&
 613       base::StringToInt(time_fields[1], &exploded.minute) &&
 614       base::StringToInt(time_fields[2], &exploded.second)) {
 615     base::Time parsed_time = base::Time::FromUTCExploded(exploded);
 616     if (parsed_time.is_null())
 617       return false;
 618
 619     *out = parsed_time;
 620     return true;
 621   }
 622
 623   return false;
 624 }
 625
 626 }  // namespace media