media/cast/test/fake_media_source.cc

   1 // Copyright 2014 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/cast/test/fake_media_source.h"
   6
   7 #include "base/bind.h"
   8 #include "base/files/scoped_file.h"
   9 #include "base/logging.h"
  10 #include "base/rand_util.h"
  11 #include "base/strings/string_number_conversions.h"
  12 #include "media/base/audio_buffer.h"
  13 #include "media/base/audio_bus.h"
  14 #include "media/base/audio_fifo.h"
  15 #include "media/base/audio_timestamp_helper.h"
  16 #include "media/base/media.h"
  17 #include "media/base/video_frame.h"
  18 #include "media/base/video_util.h"
  19 #include "media/cast/cast_sender.h"
  20 #include "media/cast/test/utility/audio_utility.h"
  21 #include "media/cast/test/utility/video_utility.h"
  22 #include "media/ffmpeg/ffmpeg_common.h"
  23 #include "media/ffmpeg/ffmpeg_deleters.h"
  24 #include "media/filters/ffmpeg_glue.h"
  25 #include "media/filters/in_memory_url_protocol.h"
  26 #include "ui/gfx/geometry/size.h"
  27
  28 namespace {
  29
  30 static const int kSoundFrequency = 440;  // Frequency of sinusoid wave.
  31 static const float kSoundVolume = 0.10f;
  32 static const int kAudioFrameMs = 10;  // Each audio frame is exactly 10ms.
  33 static const int kAudioPacketsPerSecond = 1000 / kAudioFrameMs;
  34
  35 // Bounds for variable frame size mode.
  36 static const int kMinFakeFrameWidth = 60;
  37 static const int kMinFakeFrameHeight = 34;
  38 static const int kStartingFakeFrameWidth = 854;
  39 static const int kStartingFakeFrameHeight = 480;
  40 static const int kMaxFakeFrameWidth = 1280;
  41 static const int kMaxFakeFrameHeight = 720;
  42 static const int kMaxFrameSizeChangeMillis = 5000;
  43
  44 void AVFreeFrame(AVFrame* frame) {
  45   av_frame_free(&frame);
  46 }
  47
  48 base::TimeDelta PtsToTimeDelta(int64 pts, const AVRational& time_base) {
  49   return pts * base::TimeDelta::FromSeconds(1) * time_base.num / time_base.den;
  50 }
  51
  52 int64 TimeDeltaToPts(base::TimeDelta delta, const AVRational& time_base) {
  53   return static_cast<int64>(
  54       delta.InSecondsF() * time_base.den / time_base.num +
  55       0.5 /* rounding */);
  56 }
  57
  58 }  // namespace
  59
  60 namespace media {
  61 namespace cast {
  62
  63 FakeMediaSource::FakeMediaSource(
  64     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  65     base::TickClock* clock,
  66     const AudioSenderConfig& audio_config,
  67     const VideoSenderConfig& video_config,
  68     bool keep_frames)
  69     : task_runner_(task_runner),
  70       output_audio_params_(AudioParameters::AUDIO_PCM_LINEAR,
  71                            media::GuessChannelLayout(audio_config.channels),
  72                            audio_config.frequency,
  73                            32,
  74                            audio_config.frequency / kAudioPacketsPerSecond),
  75       video_config_(video_config),
  76       keep_frames_(keep_frames),
  77       variable_frame_size_mode_(false),
  78       synthetic_count_(0),
  79       clock_(clock),
  80       audio_frame_count_(0),
  81       video_frame_count_(0),
  82       av_format_context_(NULL),
  83       audio_stream_index_(-1),
  84       playback_rate_(1.0),
  85       video_stream_index_(-1),
  86       video_frame_rate_numerator_(video_config.max_frame_rate),
  87       video_frame_rate_denominator_(1),
  88       video_first_pts_(0),
  89       video_first_pts_set_(false),
  90       weak_factory_(this) {
  91   CHECK(output_audio_params_.IsValid());
  92   audio_bus_factory_.reset(new TestAudioBusFactory(audio_config.channels,
  93                                                    audio_config.frequency,
  94                                                    kSoundFrequency,
  95                                                    kSoundVolume));
  96 }
  97
  98 FakeMediaSource::~FakeMediaSource() {
  99 }
 100
 101 void FakeMediaSource::SetSourceFile(const base::FilePath& video_file,
 102                                     int final_fps) {
 103   DCHECK(!video_file.empty());
 104
 105   LOG(INFO) << "Source: " << video_file.value();
 106   if (!file_data_.Initialize(video_file)) {
 107     LOG(ERROR) << "Cannot load file.";
 108     return;
 109   }
 110   protocol_.reset(
 111       new InMemoryUrlProtocol(file_data_.data(), file_data_.length(), false));
 112   glue_.reset(new FFmpegGlue(protocol_.get()));
 113
 114   if (!glue_->OpenContext()) {
 115     LOG(ERROR) << "Cannot open file.";
 116     return;
 117   }
 118
 119   // AVFormatContext is owned by the glue.
 120   av_format_context_ = glue_->format_context();
 121   if (avformat_find_stream_info(av_format_context_, NULL) < 0) {
 122     LOG(ERROR) << "Cannot find stream information.";
 123     return;
 124   }
 125
 126   // Prepare FFmpeg decoders.
 127   for (unsigned int i = 0; i < av_format_context_->nb_streams; ++i) {
 128     AVStream* av_stream = av_format_context_->streams[i];
 129     AVCodecContext* av_codec_context = av_stream->codec;
 130     AVCodec* av_codec = avcodec_find_decoder(av_codec_context->codec_id);
 131
 132     if (!av_codec) {
 133       LOG(ERROR) << "Cannot find decoder for the codec: "
 134                  << av_codec_context->codec_id;
 135       continue;
 136     }
 137
 138     // Number of threads for decoding.
 139     av_codec_context->thread_count = 2;
 140     av_codec_context->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
 141     av_codec_context->request_sample_fmt = AV_SAMPLE_FMT_S16;
 142
 143     if (avcodec_open2(av_codec_context, av_codec, NULL) < 0) {
 144       LOG(ERROR) << "Cannot open AVCodecContext for the codec: "
 145                  << av_codec_context->codec_id;
 146       return;
 147     }
 148
 149     if (av_codec->type == AVMEDIA_TYPE_AUDIO) {
 150       if (av_codec_context->sample_fmt == AV_SAMPLE_FMT_S16P) {
 151         LOG(ERROR) << "Audio format not supported.";
 152         continue;
 153       }
 154       ChannelLayout layout = ChannelLayoutToChromeChannelLayout(
 155           av_codec_context->channel_layout,
 156           av_codec_context->channels);
 157       if (layout == CHANNEL_LAYOUT_UNSUPPORTED) {
 158         LOG(ERROR) << "Unsupported audio channels layout.";
 159         continue;
 160       }
 161       if (audio_stream_index_ != -1) {
 162         LOG(WARNING) << "Found multiple audio streams.";
 163       }
 164       audio_stream_index_ = static_cast<int>(i);
 165       source_audio_params_.Reset(
 166           AudioParameters::AUDIO_PCM_LINEAR,
 167           layout,
 168           av_codec_context->sample_rate,
 169           8 * av_get_bytes_per_sample(av_codec_context->sample_fmt),
 170           av_codec_context->sample_rate / kAudioPacketsPerSecond);
 171       source_audio_params_.set_channels_for_discrete(
 172           av_codec_context->channels);
 173       CHECK(source_audio_params_.IsValid());
 174       LOG(INFO) << "Source file has audio.";
 175     } else if (av_codec->type == AVMEDIA_TYPE_VIDEO) {
 176       VideoPixelFormat format =
 177           AVPixelFormatToVideoPixelFormat(av_codec_context->pix_fmt);
 178       if (format != PIXEL_FORMAT_YV12) {
 179         LOG(ERROR) << "Cannot handle non YV12 video format: " << format;
 180         continue;
 181       }
 182       if (video_stream_index_ != -1) {
 183         LOG(WARNING) << "Found multiple video streams.";
 184       }
 185       video_stream_index_ = static_cast<int>(i);
 186       if (final_fps > 0) {
 187         // If video is played at a manual speed audio needs to match.
 188         playback_rate_ = 1.0 * final_fps *
 189             av_stream->r_frame_rate.den / av_stream->r_frame_rate.num;
 190         video_frame_rate_numerator_ = final_fps;
 191         video_frame_rate_denominator_ = 1;
 192       } else {
 193         playback_rate_ = 1.0;
 194         video_frame_rate_numerator_ = av_stream->r_frame_rate.num;
 195         video_frame_rate_denominator_ = av_stream->r_frame_rate.den;
 196       }
 197       LOG(INFO) << "Source file has video.";
 198     } else {
 199       LOG(ERROR) << "Unknown stream type; ignore.";
 200     }
 201   }
 202
 203   Rewind();
 204 }
 205
 206 void FakeMediaSource::SetVariableFrameSizeMode(bool enabled) {
 207   variable_frame_size_mode_ = enabled;
 208 }
 209
 210 void FakeMediaSource::Start(scoped_refptr<AudioFrameInput> audio_frame_input,
 211                             scoped_refptr<VideoFrameInput> video_frame_input) {
 212   audio_frame_input_ = audio_frame_input;
 213   video_frame_input_ = video_frame_input;
 214
 215   LOG(INFO) << "Max Frame rate: " << video_config_.max_frame_rate;
 216   LOG(INFO) << "Source Frame rate: "
 217             << video_frame_rate_numerator_ << "/"
 218             << video_frame_rate_denominator_ << " fps.";
 219   LOG(INFO) << "Audio playback rate: " << playback_rate_;
 220
 221   if (start_time_.is_null())
 222     start_time_ = clock_->NowTicks();
 223
 224   if (!is_transcoding_audio() && !is_transcoding_video()) {
 225     // Send fake patterns.
 226     task_runner_->PostTask(
 227         FROM_HERE,
 228         base::Bind(&FakeMediaSource::SendNextFakeFrame,
 229                    weak_factory_.GetWeakPtr()));
 230     return;
 231   }
 232
 233   // Send transcoding streams.
 234   audio_algo_.Initialize(source_audio_params_);
 235   audio_algo_.FlushBuffers();
 236   audio_fifo_input_bus_ = AudioBus::Create(
 237       source_audio_params_.channels(),
 238       source_audio_params_.frames_per_buffer());
 239   // Audio FIFO can carry all data fron AudioRendererAlgorithm.
 240   audio_fifo_.reset(
 241       new AudioFifo(source_audio_params_.channels(),
 242                     audio_algo_.QueueCapacity()));
 243   audio_converter_.reset(new media::AudioConverter(
 244       source_audio_params_, output_audio_params_, true));
 245   audio_converter_->AddInput(this);
 246   task_runner_->PostTask(
 247       FROM_HERE,
 248       base::Bind(&FakeMediaSource::SendNextFrame, weak_factory_.GetWeakPtr()));
 249 }
 250
 251 void FakeMediaSource::SendNextFakeFrame() {
 252   UpdateNextFrameSize();
 253   scoped_refptr<VideoFrame> video_frame =
 254       VideoFrame::CreateBlackFrame(current_frame_size_);
 255   PopulateVideoFrame(video_frame.get(), synthetic_count_);
 256   ++synthetic_count_;
 257
 258   const base::TimeTicks now = clock_->NowTicks();
 259
 260   base::TimeDelta video_time = VideoFrameTime(++video_frame_count_);
 261   video_frame->set_timestamp(video_time);
 262   if (keep_frames_)
 263     inserted_video_frame_queue_.push(video_frame);
 264   video_frame_input_->InsertRawVideoFrame(video_frame,
 265                                           start_time_ + video_time);
 266
 267   // Send just enough audio data to match next video frame's time.
 268   base::TimeDelta audio_time = AudioFrameTime(audio_frame_count_);
 269   while (audio_time < video_time) {
 270     if (is_transcoding_audio()) {
 271       Decode(true);
 272       CHECK(!audio_bus_queue_.empty()) << "No audio decoded.";
 273       scoped_ptr<AudioBus> bus(audio_bus_queue_.front());
 274       audio_bus_queue_.pop();
 275       audio_frame_input_->InsertAudio(
 276           bus.Pass(), start_time_ + audio_time);
 277     } else {
 278       audio_frame_input_->InsertAudio(
 279           audio_bus_factory_->NextAudioBus(
 280               base::TimeDelta::FromMilliseconds(kAudioFrameMs)),
 281           start_time_ + audio_time);
 282     }
 283     audio_time = AudioFrameTime(++audio_frame_count_);
 284   }
 285
 286   // This is the time since FakeMediaSource was started.
 287   const base::TimeDelta elapsed_time = now - start_time_;
 288
 289   // Handle the case when frame generation cannot keep up.
 290   // Move the time ahead to match the next frame.
 291   while (video_time < elapsed_time) {
 292     LOG(WARNING) << "Skipping one frame.";
 293     video_time = VideoFrameTime(++video_frame_count_);
 294   }
 295
 296   task_runner_->PostDelayedTask(
 297       FROM_HERE,
 298       base::Bind(&FakeMediaSource::SendNextFakeFrame,
 299                  weak_factory_.GetWeakPtr()),
 300       video_time - elapsed_time);
 301 }
 302
 303 void FakeMediaSource::UpdateNextFrameSize() {
 304   if (variable_frame_size_mode_) {
 305     bool update_size_change_time = false;
 306     if (current_frame_size_.IsEmpty()) {
 307       current_frame_size_ = gfx::Size(kStartingFakeFrameWidth,
 308                                       kStartingFakeFrameHeight);
 309       update_size_change_time = true;
 310     } else if (clock_->NowTicks() >= next_frame_size_change_time_) {
 311       current_frame_size_ = gfx::Size(
 312           base::RandInt(kMinFakeFrameWidth, kMaxFakeFrameWidth),
 313           base::RandInt(kMinFakeFrameHeight, kMaxFakeFrameHeight));
 314       update_size_change_time = true;
 315     }
 316
 317     if (update_size_change_time) {
 318       next_frame_size_change_time_ = clock_->NowTicks() +
 319           base::TimeDelta::FromMillisecondsD(
 320               base::RandDouble() * kMaxFrameSizeChangeMillis);
 321     }
 322   } else {
 323     current_frame_size_ = gfx::Size(kStartingFakeFrameWidth,
 324                                     kStartingFakeFrameHeight);
 325     next_frame_size_change_time_ = base::TimeTicks();
 326   }
 327 }
 328
 329 bool FakeMediaSource::SendNextTranscodedVideo(base::TimeDelta elapsed_time) {
 330   if (!is_transcoding_video())
 331     return false;
 332
 333   Decode(false);
 334   if (video_frame_queue_.empty())
 335     return false;
 336
 337   const scoped_refptr<VideoFrame> video_frame = video_frame_queue_.front();
 338   if (elapsed_time < video_frame->timestamp())
 339     return false;
 340   video_frame_queue_.pop();
 341
 342   // Use the timestamp from the file if we're transcoding.
 343   video_frame->set_timestamp(ScaleTimestamp(video_frame->timestamp()));
 344   if (keep_frames_)
 345     inserted_video_frame_queue_.push(video_frame);
 346   video_frame_input_->InsertRawVideoFrame(
 347       video_frame, start_time_ + video_frame->timestamp());
 348
 349   // Make sure queue is not empty.
 350   Decode(false);
 351   return true;
 352 }
 353
 354 bool FakeMediaSource::SendNextTranscodedAudio(base::TimeDelta elapsed_time) {
 355   if (!is_transcoding_audio())
 356     return false;
 357
 358   Decode(true);
 359   if (audio_bus_queue_.empty())
 360     return false;
 361
 362   base::TimeDelta audio_time = audio_sent_ts_->GetTimestamp();
 363   if (elapsed_time < audio_time)
 364     return false;
 365   scoped_ptr<AudioBus> bus(audio_bus_queue_.front());
 366   audio_bus_queue_.pop();
 367   audio_sent_ts_->AddFrames(bus->frames());
 368   audio_frame_input_->InsertAudio(
 369       bus.Pass(), start_time_ + audio_time);
 370
 371   // Make sure queue is not empty.
 372   Decode(true);
 373   return true;
 374 }
 375
 376 void FakeMediaSource::SendNextFrame() {
 377   // Send as much as possible. Audio is sent according to
 378   // system time.
 379   while (SendNextTranscodedAudio(clock_->NowTicks() - start_time_)) {
 380   }
 381
 382   // Video is sync'ed to audio.
 383   while (SendNextTranscodedVideo(audio_sent_ts_->GetTimestamp())) {
 384   }
 385
 386   if (audio_bus_queue_.empty() && video_frame_queue_.empty()) {
 387     // Both queues are empty can only mean that we have reached
 388     // the end of the stream.
 389     LOG(INFO) << "Rewind.";
 390     Rewind();
 391   }
 392
 393   // Send next send.
 394   task_runner_->PostDelayedTask(
 395       FROM_HERE,
 396       base::Bind(&FakeMediaSource::SendNextFrame, weak_factory_.GetWeakPtr()),
 397       base::TimeDelta::FromMilliseconds(kAudioFrameMs));
 398 }
 399
 400 base::TimeDelta FakeMediaSource::VideoFrameTime(int frame_number) {
 401   return frame_number * base::TimeDelta::FromSeconds(1) *
 402       video_frame_rate_denominator_ / video_frame_rate_numerator_;
 403 }
 404
 405 base::TimeDelta FakeMediaSource::ScaleTimestamp(base::TimeDelta timestamp) {
 406   return base::TimeDelta::FromSecondsD(timestamp.InSecondsF() / playback_rate_);
 407 }
 408
 409 base::TimeDelta FakeMediaSource::AudioFrameTime(int frame_number) {
 410   return frame_number * base::TimeDelta::FromMilliseconds(kAudioFrameMs);
 411 }
 412
 413 void FakeMediaSource::Rewind() {
 414   CHECK(av_seek_frame(av_format_context_, -1, 0, AVSEEK_FLAG_BACKWARD) >= 0)
 415       << "Failed to rewind to the beginning.";
 416 }
 417
 418 ScopedAVPacket FakeMediaSource::DemuxOnePacket(bool* audio) {
 419   ScopedAVPacket packet(new AVPacket());
 420   if (av_read_frame(av_format_context_, packet.get()) < 0) {
 421     VLOG(1) << "Failed to read one AVPacket.";
 422     packet.reset();
 423     return packet.Pass();
 424   }
 425
 426   int stream_index = static_cast<int>(packet->stream_index);
 427   if (stream_index == audio_stream_index_) {
 428     *audio = true;
 429   } else if (stream_index == video_stream_index_) {
 430     *audio = false;
 431   } else {
 432     // Ignore unknown packet.
 433     LOG(INFO) << "Unknown packet.";
 434     packet.reset();
 435   }
 436   return packet.Pass();
 437 }
 438
 439 void FakeMediaSource::DecodeAudio(ScopedAVPacket packet) {
 440   // Audio.
 441   AVFrame* avframe = av_frame_alloc();
 442
 443   // Make a shallow copy of packet so we can slide packet.data as frames are
 444   // decoded from the packet; otherwise av_free_packet() will corrupt memory.
 445   AVPacket packet_temp = *packet.get();
 446
 447   do {
 448     int frame_decoded = 0;
 449     int result = avcodec_decode_audio4(
 450         av_audio_context(), avframe, &frame_decoded, &packet_temp);
 451     CHECK(result >= 0) << "Failed to decode audio.";
 452     packet_temp.size -= result;
 453     packet_temp.data += result;
 454     if (!frame_decoded)
 455       continue;
 456
 457     int frames_read = avframe->nb_samples;
 458     if (frames_read < 0)
 459       break;
 460
 461     if (!audio_sent_ts_) {
 462       // Initialize the base time to the first packet in the file.
 463       // This is set to the frequency we send to the receiver.
 464       // Not the frequency of the source file. This is because we
 465       // increment the frame count by samples we sent.
 466       audio_sent_ts_.reset(
 467           new AudioTimestampHelper(output_audio_params_.sample_rate()));
 468       // For some files this is an invalid value.
 469       base::TimeDelta base_ts;
 470       audio_sent_ts_->SetBaseTimestamp(base_ts);
 471     }
 472
 473     scoped_refptr<AudioBuffer> buffer =
 474         AudioBuffer::CopyFrom(
 475             AVSampleFormatToSampleFormat(
 476                 av_audio_context()->sample_fmt),
 477             ChannelLayoutToChromeChannelLayout(
 478                 av_audio_context()->channel_layout,
 479                 av_audio_context()->channels),
 480             av_audio_context()->channels,
 481             av_audio_context()->sample_rate,
 482             frames_read,
 483             &avframe->data[0],
 484             PtsToTimeDelta(avframe->pkt_pts, av_audio_stream()->time_base));
 485     audio_algo_.EnqueueBuffer(buffer);
 486     av_frame_unref(avframe);
 487   } while (packet_temp.size > 0);
 488   av_frame_free(&avframe);
 489
 490   const int frames_needed_to_scale =
 491       playback_rate_ * av_audio_context()->sample_rate /
 492       kAudioPacketsPerSecond;
 493   while (frames_needed_to_scale <= audio_algo_.frames_buffered()) {
 494     if (!audio_algo_.FillBuffer(audio_fifo_input_bus_.get(), 0,
 495                                 audio_fifo_input_bus_->frames(),
 496                                 playback_rate_)) {
 497       // Nothing can be scaled. Decode some more.
 498       return;
 499     }
 500
 501     // Prevent overflow of audio data in the FIFO.
 502     if (audio_fifo_input_bus_->frames() + audio_fifo_->frames()
 503         <= audio_fifo_->max_frames()) {
 504       audio_fifo_->Push(audio_fifo_input_bus_.get());
 505     } else {
 506       LOG(WARNING) << "Audio FIFO full; dropping samples.";
 507     }
 508
 509     // Make sure there's enough data to resample audio.
 510     if (audio_fifo_->frames() <
 511         2 * source_audio_params_.sample_rate() / kAudioPacketsPerSecond) {
 512       continue;
 513     }
 514
 515     scoped_ptr<media::AudioBus> resampled_bus(
 516         media::AudioBus::Create(
 517             output_audio_params_.channels(),
 518             output_audio_params_.sample_rate() / kAudioPacketsPerSecond));
 519     audio_converter_->Convert(resampled_bus.get());
 520     audio_bus_queue_.push(resampled_bus.release());
 521   }
 522 }
 523
 524 void FakeMediaSource::DecodeVideo(ScopedAVPacket packet) {
 525   // Video.
 526   int got_picture;
 527   AVFrame* avframe = av_frame_alloc();
 528   CHECK(avcodec_decode_video2(
 529       av_video_context(), avframe, &got_picture, packet.get()) >= 0)
 530       << "Video decode error.";
 531   if (!got_picture) {
 532     av_frame_free(&avframe);
 533     return;
 534   }
 535   gfx::Size size(av_video_context()->width, av_video_context()->height);
 536
 537   if (!video_first_pts_set_) {
 538     video_first_pts_ = avframe->pkt_pts;
 539     video_first_pts_set_ = true;
 540   }
 541   const AVRational& time_base = av_video_stream()->time_base;
 542   base::TimeDelta timestamp =
 543       PtsToTimeDelta(avframe->pkt_pts - video_first_pts_, time_base);
 544   if (timestamp < last_video_frame_timestamp_) {
 545     // Stream has rewound.  Rebase |video_first_pts_|.
 546     const AVRational& frame_rate = av_video_stream()->r_frame_rate;
 547     timestamp = last_video_frame_timestamp_ +
 548         (base::TimeDelta::FromSeconds(1) * frame_rate.den / frame_rate.num);
 549     const int64 adjustment_pts = TimeDeltaToPts(timestamp, time_base);
 550     video_first_pts_ = avframe->pkt_pts - adjustment_pts;
 551   }
 552
 553   video_frame_queue_.push(VideoFrame::WrapExternalYuvData(
 554       media::PIXEL_FORMAT_YV12, size, gfx::Rect(size), size,
 555       avframe->linesize[0], avframe->linesize[1], avframe->linesize[2],
 556       avframe->data[0], avframe->data[1], avframe->data[2], timestamp));
 557   video_frame_queue_.back()->AddDestructionObserver(
 558       base::Bind(&AVFreeFrame, avframe));
 559   last_video_frame_timestamp_ = timestamp;
 560 }
 561
 562 void FakeMediaSource::Decode(bool decode_audio) {
 563   // Read the stream until one video frame can be decoded.
 564   while (true) {
 565     if (decode_audio && !audio_bus_queue_.empty())
 566       return;
 567     if (!decode_audio && !video_frame_queue_.empty())
 568       return;
 569
 570     bool audio_packet = false;
 571     ScopedAVPacket packet = DemuxOnePacket(&audio_packet);
 572     if (!packet) {
 573       VLOG(1) << "End of stream.";
 574       return;
 575     }
 576
 577     if (audio_packet)
 578       DecodeAudio(packet.Pass());
 579     else
 580       DecodeVideo(packet.Pass());
 581   }
 582 }
 583
 584 double FakeMediaSource::ProvideInput(media::AudioBus* output_bus,
 585                                    base::TimeDelta buffer_delay) {
 586   if (audio_fifo_->frames() >= output_bus->frames()) {
 587     audio_fifo_->Consume(output_bus, 0, output_bus->frames());
 588     return 1.0;
 589   } else {
 590     LOG(WARNING) << "Not enough audio data for resampling.";
 591     output_bus->Zero();
 592     return 0.0;
 593   }
 594 }
 595
 596 scoped_refptr<media::VideoFrame>
 597 FakeMediaSource::PopOldestInsertedVideoFrame() {
 598   CHECK(!inserted_video_frame_queue_.empty());
 599   scoped_refptr<media::VideoFrame> video_frame =
 600       inserted_video_frame_queue_.front();
 601   inserted_video_frame_queue_.pop();
 602   return video_frame;
 603 }
 604
 605 AVStream* FakeMediaSource::av_audio_stream() {
 606   return av_format_context_->streams[audio_stream_index_];
 607 }
 608
 609 AVStream* FakeMediaSource::av_video_stream() {
 610   return av_format_context_->streams[video_stream_index_];
 611 }
 612
 613 AVCodecContext* FakeMediaSource::av_audio_context() {
 614   return av_audio_stream()->codec;
 615 }
 616
 617 AVCodecContext* FakeMediaSource::av_video_context() {
 618   return av_video_stream()->codec;
 619 }
 620
 621 }  // namespace cast
 622 }  // namespace media