path: root/media/filters/chunk_demuxer.cc

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/filters/chunk_demuxer.h"

#include <algorithm>
#include <limits>
#include <list>

#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/stl_util.h"
#include "media/base/audio_decoder_config.h"
#include "media/base/bind_to_current_loop.h"
#include "media/base/stream_parser_buffer.h"
#include "media/base/timestamp_constants.h"
#include "media/base/video_decoder_config.h"
#include "media/filters/frame_processor.h"
#include "media/filters/stream_parser_factory.h"

using base::TimeDelta;

namespace media {

static TimeDelta EndTimestamp(const StreamParser::BufferQueue& queue) {
  return queue.back()->timestamp() + queue.back()->duration();
}

// List of time ranges for each SourceBuffer.
typedef std::list<Ranges<TimeDelta> > RangesList;
static Ranges<TimeDelta> ComputeIntersection(const RangesList& activeRanges,
                                             bool ended) {
  // Implementation of HTMLMediaElement.buffered algorithm in MSE spec.
  // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#dom-htmlmediaelement.buffered

  // Step 1: If activeSourceBuffers.length equals 0 then return an empty
  //  TimeRanges object and abort these steps.
  if (activeRanges.empty())
    return Ranges<TimeDelta>();

  // Step 2: Let active ranges be the ranges returned by buffered for each
  //  SourceBuffer object in activeSourceBuffers.
  // Step 3: Let highest end time be the largest range end time in the active
  //  ranges.
  TimeDelta highest_end_time;
  for (RangesList::const_iterator itr = activeRanges.begin();
       itr != activeRanges.end(); ++itr) {
    if (!itr->size())
      continue;

    highest_end_time = std::max(highest_end_time, itr->end(itr->size() - 1));
  }

  // Step 4: Let intersection ranges equal a TimeRange object containing a
  //  single range from 0 to highest end time.
  Ranges<TimeDelta> intersection_ranges;
  intersection_ranges.Add(TimeDelta(), highest_end_time);

  // Step 5: For each SourceBuffer object in activeSourceBuffers run the
  //  following steps:
  for (RangesList::const_iterator itr = activeRanges.begin();
       itr != activeRanges.end(); ++itr) {
    // Step 5.1: Let source ranges equal the ranges returned by the buffered
    //  attribute on the current SourceBuffer.
    Ranges<TimeDelta> source_ranges = *itr;

    // Step 5.2: If readyState is "ended", then set the end time on the last
    //  range in source ranges to highest end time.
    if (ended && source_ranges.size() > 0u) {
      source_ranges.Add(source_ranges.start(source_ranges.size() - 1),
                        highest_end_time);
    }

    // Step 5.3: Let new intersection ranges equal the intersection between
    // the intersection ranges and the source ranges.
    // Step 5.4: Replace the ranges in intersection ranges with the new
    // intersection ranges.
    intersection_ranges = intersection_ranges.IntersectionWith(source_ranges);
  }

  return intersection_ranges;
}

// Contains state belonging to a source id.
// TODO: SourceState needs to be moved to a separate file and covered with unit
// tests (see crbug.com/525836)
class SourceState {
 public:
  // Callback signature used to create ChunkDemuxerStreams.
  typedef base::Callback<ChunkDemuxerStream*(
      DemuxerStream::Type)> CreateDemuxerStreamCB;

  typedef ChunkDemuxer::InitSegmentReceivedCB InitSegmentReceivedCB;

  typedef base::Callback<void(
      ChunkDemuxerStream*, const TextTrackConfig&)> NewTextTrackCB;

  SourceState(scoped_ptr<StreamParser> stream_parser,
              scoped_ptr<FrameProcessor> frame_processor,
              const CreateDemuxerStreamCB& create_demuxer_stream_cb,
              const scoped_refptr<MediaLog>& media_log);

  ~SourceState();

  void Init(const StreamParser::InitCB& init_cb,
            bool allow_audio,
            bool allow_video,
            const StreamParser::EncryptedMediaInitDataCB&
                encrypted_media_init_data_cb,
            const NewTextTrackCB& new_text_track_cb);

  // Appends new data to the StreamParser.
  // Returns true if the data was successfully appended. Returns false if an
  // error occurred. |*timestamp_offset| is used and possibly updated by the
  // append. |append_window_start| and |append_window_end| correspond to the MSE
  // spec's similarly named source buffer attributes that are used in coded
  // frame processing. |init_segment_received_cb| is run for each new fully
  // parsed initialization segment.
  bool Append(const uint8* data,
              size_t length,
              TimeDelta append_window_start,
              TimeDelta append_window_end,
              TimeDelta* timestamp_offset,
              const InitSegmentReceivedCB& init_segment_received_cb);

  // Aborts the current append sequence and resets the parser.
  void Abort(TimeDelta append_window_start,
             TimeDelta append_window_end,
             TimeDelta* timestamp_offset);

  // Calls Remove(|start|, |end|, |duration|) on all
  // ChunkDemuxerStreams managed by this object.
  void Remove(TimeDelta start, TimeDelta end, TimeDelta duration);

  // If the buffer is full, attempts to try to free up space, as specified in
  // the "Coded Frame Eviction Algorithm" in the Media Source Extensions Spec.
  // Returns false iff buffer is still full after running eviction.
  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
  bool EvictCodedFrames(DecodeTimestamp media_time, size_t newDataSize);

  // Returns true if currently parsing a media segment, or false otherwise.
  bool parsing_media_segment() const { return parsing_media_segment_; }

  // Sets |frame_processor_|'s sequence mode to |sequence_mode|.
  void SetSequenceMode(bool sequence_mode);

  // Signals the coded frame processor to update its group start timestamp to be
  // |timestamp_offset| if it is in sequence append mode.
  void SetGroupStartTimestampIfInSequenceMode(base::TimeDelta timestamp_offset);

  // Returns the range of buffered data in this source, capped at |duration|.
  // |ended| - Set to true if end of stream has been signaled and the special
  // end of stream range logic needs to be executed.
  Ranges<TimeDelta> GetBufferedRanges(TimeDelta duration, bool ended) const;

  // Returns the highest buffered duration across all streams managed
  // by this object.
  // Returns TimeDelta() if none of the streams contain buffered data.
  TimeDelta GetMaxBufferedDuration() const;

  // Helper methods that call methods with similar names on all the
  // ChunkDemuxerStreams managed by this object.
  void StartReturningData();
  void AbortReads();
  void Seek(TimeDelta seek_time);
  void CompletePendingReadIfPossible();
  void OnSetDuration(TimeDelta duration);
  void MarkEndOfStream();
  void UnmarkEndOfStream();
  void Shutdown();
  // Sets the memory limit on each stream of a specific type.
  // |memory_limit| is the maximum number of bytes each stream of type |type|
  // is allowed to hold in its buffer.
  void SetMemoryLimits(DemuxerStream::Type type, size_t memory_limit);
  bool IsSeekWaitingForData() const;

 private:
  // Called by the |stream_parser_| when a new initialization segment is
  // encountered.
  // Returns true on a successful call. Returns false if an error occurred while
  // processing decoder configurations.
  bool OnNewConfigs(bool allow_audio, bool allow_video,
                    const AudioDecoderConfig& audio_config,
                    const VideoDecoderConfig& video_config,
                    const StreamParser::TextTrackConfigMap& text_configs);

  // Called by the |stream_parser_| at the beginning of a new media segment.
  void OnNewMediaSegment();

  // Called by the |stream_parser_| at the end of a media segment.
  void OnEndOfMediaSegment();

  // Called by the |stream_parser_| when new buffers have been parsed.
  // It processes the new buffers using |frame_processor_|, which includes
  // appending the processed frames to associated demuxer streams for each
  // frame's track.
  // Returns true on a successful call. Returns false if an error occurred while
  // processing the buffers.
  bool OnNewBuffers(const StreamParser::BufferQueue& audio_buffers,
                    const StreamParser::BufferQueue& video_buffers,
                    const StreamParser::TextBufferQueueMap& text_map);

  void OnSourceInitDone(const StreamParser::InitParameters& params);

  // EstimateVideoDataSize uses some heuristics to estimate the size of the
  // video size in the chunk of muxed audio/video data without parsing it.
  // This is used by EvictCodedFrames algorithm, which happens before Append
  // (and therefore before parsing is performed) to prepare space for new data.
  size_t EstimateVideoDataSize(size_t muxed_data_chunk_size) const;

  CreateDemuxerStreamCB create_demuxer_stream_cb_;
  NewTextTrackCB new_text_track_cb_;

  // During Append(), if OnNewBuffers() coded frame processing updates the
  // timestamp offset then |*timestamp_offset_during_append_| is also updated
  // so Append()'s caller can know the new offset. This pointer is only non-NULL
  // during the lifetime of an Append() call.
  TimeDelta* timestamp_offset_during_append_;

  // During Append(), coded frame processing triggered by OnNewBuffers()
  // requires these two attributes. These are only valid during the lifetime of
  // an Append() call.
  TimeDelta append_window_start_during_append_;
  TimeDelta append_window_end_during_append_;

  // Set to true if the next buffers appended within the append window
  // represent the start of a new media segment. This flag being set
  // triggers a call to |new_segment_cb_| when the new buffers are
  // appended. The flag is set on actual media segment boundaries and
  // when the "append window" filtering causes discontinuities in the
  // appended data.
  // TODO(wolenetz/acolwell): Investigate if we need this, or if coded frame
  // processing's discontinuity logic is enough. See http://crbug.com/351489.
  bool new_media_segment_;

  // Keeps track of whether a media segment is being parsed.
  bool parsing_media_segment_;

  // The object used to parse appended data.
  scoped_ptr<StreamParser> stream_parser_;

  ChunkDemuxerStream* audio_;  // Not owned by |this|.
  ChunkDemuxerStream* video_;  // Not owned by |this|.

  typedef std::map<StreamParser::TrackId, ChunkDemuxerStream*> TextStreamMap;
  TextStreamMap text_stream_map_;  // |this| owns the map's stream pointers.

  scoped_ptr<FrameProcessor> frame_processor_;
  scoped_refptr<MediaLog> media_log_;
  StreamParser::InitCB init_cb_;

  // During Append(), OnNewConfigs() will trigger the initialization segment
  // received algorithm. This callback is only non-NULL during the lifetime of
  // an Append() call. Note, the MSE spec explicitly disallows this algorithm
  // during an Abort(), since Abort() is allowed only to emit coded frames, and
  // only if the parser is PARSING_MEDIA_SEGMENT (not an INIT segment).
  InitSegmentReceivedCB init_segment_received_cb_;

  // Indicates that timestampOffset should be updated automatically during
  // OnNewBuffers() based on the earliest end timestamp of the buffers provided.
  // TODO(wolenetz): Refactor this function while integrating April 29, 2014
  // changes to MSE spec. See http://crbug.com/371499.
  bool auto_update_timestamp_offset_;

  DISALLOW_COPY_AND_ASSIGN(SourceState);
};

SourceState::SourceState(scoped_ptr<StreamParser> stream_parser,
                         scoped_ptr<FrameProcessor> frame_processor,
                         const CreateDemuxerStreamCB& create_demuxer_stream_cb,
                         const scoped_refptr<MediaLog>& media_log)
    : create_demuxer_stream_cb_(create_demuxer_stream_cb),
      timestamp_offset_during_append_(NULL),
      new_media_segment_(false),
      parsing_media_segment_(false),
      stream_parser_(stream_parser.release()),
      audio_(NULL),
      video_(NULL),
      frame_processor_(frame_processor.release()),
      media_log_(media_log),
      auto_update_timestamp_offset_(false) {
  DCHECK(!create_demuxer_stream_cb_.is_null());
  DCHECK(frame_processor_);
}

SourceState::~SourceState() {
  Shutdown();

  STLDeleteValues(&text_stream_map_);
}

void SourceState::Init(
    const StreamParser::InitCB& init_cb,
    bool allow_audio,
    bool allow_video,
    const StreamParser::EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
    const NewTextTrackCB& new_text_track_cb) {
  new_text_track_cb_ = new_text_track_cb;
  init_cb_ = init_cb;

  stream_parser_->Init(
      base::Bind(&SourceState::OnSourceInitDone, base::Unretained(this)),
      base::Bind(&SourceState::OnNewConfigs, base::Unretained(this),
                 allow_audio, allow_video),
      base::Bind(&SourceState::OnNewBuffers, base::Unretained(this)),
      new_text_track_cb_.is_null(), encrypted_media_init_data_cb,
      base::Bind(&SourceState::OnNewMediaSegment, base::Unretained(this)),
      base::Bind(&SourceState::OnEndOfMediaSegment, base::Unretained(this)),
      media_log_);
}

void SourceState::SetSequenceMode(bool sequence_mode) {
  DCHECK(!parsing_media_segment_);

  frame_processor_->SetSequenceMode(sequence_mode);
}

void SourceState::SetGroupStartTimestampIfInSequenceMode(
    base::TimeDelta timestamp_offset) {
  DCHECK(!parsing_media_segment_);

  frame_processor_->SetGroupStartTimestampIfInSequenceMode(timestamp_offset);
}

bool SourceState::Append(
    const uint8* data,
    size_t length,
    TimeDelta append_window_start,
    TimeDelta append_window_end,
    TimeDelta* timestamp_offset,
    const InitSegmentReceivedCB& init_segment_received_cb) {
  DCHECK(timestamp_offset);
  DCHECK(!timestamp_offset_during_append_);
  DCHECK(!init_segment_received_cb.is_null());
  DCHECK(init_segment_received_cb_.is_null());
  append_window_start_during_append_ = append_window_start;
  append_window_end_during_append_ = append_window_end;
  timestamp_offset_during_append_ = timestamp_offset;
  init_segment_received_cb_= init_segment_received_cb;

  // TODO(wolenetz/acolwell): Curry and pass a NewBuffersCB here bound with
  // append window and timestamp offset pointer. See http://crbug.com/351454.
  bool result = stream_parser_->Parse(data, length);
  if (!result) {
    MEDIA_LOG(ERROR, media_log_)
        << __FUNCTION__ << ": stream parsing failed."
        << " Data size=" << length
        << " append_window_start=" << append_window_start.InSecondsF()
        << " append_window_end=" << append_window_end.InSecondsF();
  }
  timestamp_offset_during_append_ = NULL;
  init_segment_received_cb_.Reset();
  return result;
}

void SourceState::Abort(TimeDelta append_window_start,
                        TimeDelta append_window_end,
                        base::TimeDelta* timestamp_offset) {
  DCHECK(timestamp_offset);
  DCHECK(!timestamp_offset_during_append_);
  timestamp_offset_during_append_ = timestamp_offset;
  append_window_start_during_append_ = append_window_start;
  append_window_end_during_append_ = append_window_end;

  stream_parser_->Flush();
  timestamp_offset_during_append_ = NULL;

  frame_processor_->Reset();
  parsing_media_segment_ = false;
}

void SourceState::Remove(TimeDelta start, TimeDelta end, TimeDelta duration) {
  if (audio_)
    audio_->Remove(start, end, duration);

  if (video_)
    video_->Remove(start, end, duration);

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->Remove(start, end, duration);
  }
}

size_t SourceState::EstimateVideoDataSize(size_t muxed_data_chunk_size) const {
  DCHECK(audio_);
  DCHECK(video_);

  size_t videoBufferedSize = video_->GetBufferedSize();
  size_t audioBufferedSize = audio_->GetBufferedSize();
  if (videoBufferedSize == 0 || audioBufferedSize == 0) {
    // At this point either audio or video buffer is empty, which means buffer
    // levels are probably low anyway and we should have enough space in the
    // buffers for appending new data, so just take a very rough guess.
    return muxed_data_chunk_size / 2;
  }

  // We need to estimate how much audio and video data is going to be in the
  // newly appended data chunk to make space for the new data. And we need to do
  // that without parsing the data (which will happen later, in the Append
  // phase). So for now we can only rely on some heuristic here. Let's assume
  // that the proportion of the audio/video in the new data chunk is the same as
  // the current ratio of buffered audio/video.
  // Longer term this should go away once we further change the MSE GC algorithm
  // to work across all streams of a SourceBuffer (see crbug.com/520704).
  double videoBufferedSizeF = static_cast<double>(videoBufferedSize);
  double audioBufferedSizeF = static_cast<double>(audioBufferedSize);

  double totalBufferedSizeF = videoBufferedSizeF + audioBufferedSizeF;
  CHECK_GT(totalBufferedSizeF, 0.0);

  double videoRatio = videoBufferedSizeF / totalBufferedSizeF;
  CHECK_GE(videoRatio, 0.0);
  CHECK_LE(videoRatio, 1.0);
  double estimatedVideoSize = muxed_data_chunk_size * videoRatio;
  return static_cast<size_t>(estimatedVideoSize);
}

bool SourceState::EvictCodedFrames(DecodeTimestamp media_time,
                                   size_t newDataSize) {
  bool success = true;

  DVLOG(3) << __FUNCTION__ << " media_time=" << media_time.InSecondsF()
           << " newDataSize=" << newDataSize
           << " videoBufferedSize=" << (video_ ? video_->GetBufferedSize() : 0)
           << " audioBufferedSize=" << (audio_ ? audio_->GetBufferedSize() : 0);

  size_t newAudioSize = 0;
  size_t newVideoSize = 0;
  if (audio_ && video_) {
    newVideoSize = EstimateVideoDataSize(newDataSize);
    newAudioSize = newDataSize - newVideoSize;
  } else if (video_) {
    newVideoSize = newDataSize;
  } else if (audio_) {
    newAudioSize = newDataSize;
  }

  DVLOG(3) << __FUNCTION__ << " estimated audio/video sizes: "
           << " newVideoSize=" << newVideoSize
           << " newAudioSize=" << newAudioSize;

  if (audio_)
    success = audio_->EvictCodedFrames(media_time, newAudioSize) && success;

  if (video_)
    success = video_->EvictCodedFrames(media_time, newVideoSize) && success;

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    success = itr->second->EvictCodedFrames(media_time, 0) && success;
  }

  DVLOG(3) << __FUNCTION__ << " result=" << success
           << " videoBufferedSize=" << (video_ ? video_->GetBufferedSize() : 0)
           << " audioBufferedSize=" << (audio_ ? audio_->GetBufferedSize() : 0);

  return success;
}

Ranges<TimeDelta> SourceState::GetBufferedRanges(TimeDelta duration,
                                                 bool ended) const {
  // TODO(acolwell): When we start allowing disabled tracks we'll need to update
  // this code to only add ranges from active tracks.
  RangesList ranges_list;
  if (audio_)
    ranges_list.push_back(audio_->GetBufferedRanges(duration));

  if (video_)
    ranges_list.push_back(video_->GetBufferedRanges(duration));

  for (TextStreamMap::const_iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    ranges_list.push_back(itr->second->GetBufferedRanges(duration));
  }

  return ComputeIntersection(ranges_list, ended);
}

TimeDelta SourceState::GetMaxBufferedDuration() const {
  TimeDelta max_duration;

  if (audio_)
    max_duration = std::max(max_duration, audio_->GetBufferedDuration());

  if (video_)
    max_duration = std::max(max_duration, video_->GetBufferedDuration());

  for (TextStreamMap::const_iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    max_duration = std::max(max_duration, itr->second->GetBufferedDuration());
  }

  return max_duration;
}

void SourceState::StartReturningData() {
  if (audio_)
    audio_->StartReturningData();

  if (video_)
    video_->StartReturningData();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->StartReturningData();
  }
}

void SourceState::AbortReads() {
  if (audio_)
    audio_->AbortReads();

  if (video_)
    video_->AbortReads();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->AbortReads();
  }
}

void SourceState::Seek(TimeDelta seek_time) {
  if (audio_)
    audio_->Seek(seek_time);

  if (video_)
    video_->Seek(seek_time);

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->Seek(seek_time);
  }
}

void SourceState::CompletePendingReadIfPossible() {
  if (audio_)
    audio_->CompletePendingReadIfPossible();

  if (video_)
    video_->CompletePendingReadIfPossible();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->CompletePendingReadIfPossible();
  }
}

void SourceState::OnSetDuration(TimeDelta duration) {
  if (audio_)
    audio_->OnSetDuration(duration);

  if (video_)
    video_->OnSetDuration(duration);

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->OnSetDuration(duration);
  }
}

void SourceState::MarkEndOfStream() {
  if (audio_)
    audio_->MarkEndOfStream();

  if (video_)
    video_->MarkEndOfStream();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->MarkEndOfStream();
  }
}

void SourceState::UnmarkEndOfStream() {
  if (audio_)
    audio_->UnmarkEndOfStream();

  if (video_)
    video_->UnmarkEndOfStream();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->UnmarkEndOfStream();
  }
}

void SourceState::Shutdown() {
  if (audio_)
    audio_->Shutdown();

  if (video_)
    video_->Shutdown();

  for (TextStreamMap::iterator itr = text_stream_map_.begin();
       itr != text_stream_map_.end(); ++itr) {
    itr->second->Shutdown();
  }
}

void SourceState::SetMemoryLimits(DemuxerStream::Type type,
                                  size_t memory_limit) {
  switch (type) {
    case DemuxerStream::AUDIO:
      if (audio_)
        audio_->SetStreamMemoryLimit(memory_limit);
      break;
    case DemuxerStream::VIDEO:
      if (video_)
        video_->SetStreamMemoryLimit(memory_limit);
      break;
    case DemuxerStream::TEXT:
      for (TextStreamMap::iterator itr = text_stream_map_.begin();
           itr != text_stream_map_.end(); ++itr) {
        itr->second->SetStreamMemoryLimit(memory_limit);
      }
      break;
    case DemuxerStream::UNKNOWN:
    case DemuxerStream::NUM_TYPES:
      NOTREACHED();
      break;
  }
}

bool SourceState::IsSeekWaitingForData() const {
  if (audio_ && audio_->IsSeekWaitingForData())
    return true;

  if (video_ && video_->IsSeekWaitingForData())
    return true;

  // NOTE: We are intentionally not checking the text tracks
  // because text tracks are discontinuous and may not have data
  // for the seek position. This is ok and playback should not be
  // stalled because we don't have cues. If cues, with timestamps after
  // the seek time, eventually arrive they will be delivered properly
  // in response to ChunkDemuxerStream::Read() calls.

  return false;
}

bool SourceState::OnNewConfigs(
    bool allow_audio, bool allow_video,
    const AudioDecoderConfig& audio_config,
    const VideoDecoderConfig& video_config,
    const StreamParser::TextTrackConfigMap& text_configs) {
  DVLOG(1) << "OnNewConfigs(" << allow_audio << ", " << allow_video
           << ", " << audio_config.IsValidConfig()
           << ", " << video_config.IsValidConfig() << ")";
  DCHECK(!init_segment_received_cb_.is_null());

  if (!audio_config.IsValidConfig() && !video_config.IsValidConfig()) {
    DVLOG(1) << "OnNewConfigs() : Audio & video config are not valid!";
    return false;
  }

  // Signal an error if we get configuration info for stream types that weren't
  // specified in AddId() or more configs after a stream is initialized.
  if (allow_audio != audio_config.IsValidConfig()) {
    MEDIA_LOG(ERROR, media_log_)
        << "Initialization segment"
        << (audio_config.IsValidConfig() ? " has" : " does not have")
        << " an audio track, but the mimetype"
        << (allow_audio ? " specifies" : " does not specify")
        << " an audio codec.";
    return false;
  }

  if (allow_video != video_config.IsValidConfig()) {
    MEDIA_LOG(ERROR, media_log_)
        << "Initialization segment"
        << (video_config.IsValidConfig() ? " has" : " does not have")
        << " a video track, but the mimetype"
        << (allow_video ? " specifies" : " does not specify")
        << " a video codec.";
    return false;
  }

  bool success = true;
  if (audio_config.IsValidConfig()) {
    if (!audio_) {
      media_log_->SetBooleanProperty("found_audio_stream", true);
    }
    if (!audio_ ||
        audio_->audio_decoder_config().codec() != audio_config.codec()) {
      media_log_->SetStringProperty("audio_codec_name",
                                    audio_config.GetHumanReadableCodecName());
    }

    if (!audio_) {
      audio_ = create_demuxer_stream_cb_.Run(DemuxerStream::AUDIO);

      if (!audio_) {
        DVLOG(1) << "Failed to create an audio stream.";
        return false;
      }

      if (!frame_processor_->AddTrack(FrameProcessor::kAudioTrackId, audio_)) {
        DVLOG(1) << "Failed to add audio track to frame processor.";
        return false;
      }
    }

    frame_processor_->OnPossibleAudioConfigUpdate(audio_config);
    success &= audio_->UpdateAudioConfig(audio_config, media_log_);
  }

  if (video_config.IsValidConfig()) {
    if (!video_) {
      media_log_->SetBooleanProperty("found_video_stream", true);
    }
    if (!video_ ||
        video_->video_decoder_config().codec() != video_config.codec()) {
      media_log_->SetStringProperty("video_codec_name",
                                    video_config.GetHumanReadableCodecName());
    }

    if (!video_) {
      video_ = create_demuxer_stream_cb_.Run(DemuxerStream::VIDEO);

      if (!video_) {
        DVLOG(1) << "Failed to create a video stream.";
        return false;
      }

      if (!frame_processor_->AddTrack(FrameProcessor::kVideoTrackId, video_)) {
        DVLOG(1) << "Failed to add video track to frame processor.";
        return false;
      }
    }

    success &= video_->UpdateVideoConfig(video_config, media_log_);
  }

  typedef StreamParser::TextTrackConfigMap::const_iterator TextConfigItr;
  if (text_stream_map_.empty()) {
    for (TextConfigItr itr = text_configs.begin();
         itr != text_configs.end(); ++itr) {
      ChunkDemuxerStream* const text_stream =
          create_demuxer_stream_cb_.Run(DemuxerStream::TEXT);
      if (!frame_processor_->AddTrack(itr->first, text_stream)) {
        success &= false;
        MEDIA_LOG(ERROR, media_log_) << "Failed to add text track ID "
                                     << itr->first << " to frame processor.";
        break;
      }
      text_stream->UpdateTextConfig(itr->second, media_log_);
      text_stream_map_[itr->first] = text_stream;
      new_text_track_cb_.Run(text_stream, itr->second);
    }
  } else {
    const size_t text_count = text_stream_map_.size();
    if (text_configs.size() != text_count) {
      success &= false;
      MEDIA_LOG(ERROR, media_log_)
          << "The number of text track configs changed.";
    } else if (text_count == 1) {
      TextConfigItr config_itr = text_configs.begin();
      TextStreamMap::iterator stream_itr = text_stream_map_.begin();
      ChunkDemuxerStream* text_stream = stream_itr->second;
      TextTrackConfig old_config = text_stream->text_track_config();
      TextTrackConfig new_config(config_itr->second.kind(),
                                 config_itr->second.label(),
                                 config_itr->second.language(),
                                 old_config.id());
      if (!new_config.Matches(old_config)) {
        success &= false;
        MEDIA_LOG(ERROR, media_log_)
            << "New text track config does not match old one.";
      } else {
        StreamParser::TrackId old_id = stream_itr->first;
        StreamParser::TrackId new_id = config_itr->first;
        if (new_id != old_id) {
          if (frame_processor_->UpdateTrack(old_id, new_id)) {
            text_stream_map_.clear();
            text_stream_map_[config_itr->first] = text_stream;
          } else {
            success &= false;
            MEDIA_LOG(ERROR, media_log_)
                << "Error remapping single text track number";
          }
        }
      }
    } else {
      for (TextConfigItr config_itr = text_configs.begin();
           config_itr != text_configs.end(); ++config_itr) {
        TextStreamMap::iterator stream_itr =
            text_stream_map_.find(config_itr->first);
        if (stream_itr == text_stream_map_.end()) {
          success &= false;
          MEDIA_LOG(ERROR, media_log_)
              << "Unexpected text track configuration for track ID "
              << config_itr->first;
          break;
        }

        const TextTrackConfig& new_config = config_itr->second;
        ChunkDemuxerStream* stream = stream_itr->second;
        TextTrackConfig old_config = stream->text_track_config();
        if (!new_config.Matches(old_config)) {
          success &= false;
          MEDIA_LOG(ERROR, media_log_) << "New text track config for track ID "
                                       << config_itr->first
                                       << " does not match old one.";
          break;
        }
      }
    }
  }

  frame_processor_->SetAllTrackBuffersNeedRandomAccessPoint();

  DVLOG(1) << "OnNewConfigs() : " << (success ? "success" : "failed");
  if (success)
    init_segment_received_cb_.Run();

  return success;
}

void SourceState::OnNewMediaSegment() {
  DVLOG(2) << "OnNewMediaSegment()";
  parsing_media_segment_ = true;
  new_media_segment_ = true;
}

void SourceState::OnEndOfMediaSegment() {
  DVLOG(2) << "OnEndOfMediaSegment()";
  parsing_media_segment_ = false;
  new_media_segment_ = false;
}

bool SourceState::OnNewBuffers(
    const StreamParser::BufferQueue& audio_buffers,
    const StreamParser::BufferQueue& video_buffers,
    const StreamParser::TextBufferQueueMap& text_map) {
  DVLOG(2) << "OnNewBuffers()";
  DCHECK(timestamp_offset_during_append_);
  DCHECK(parsing_media_segment_);

  const TimeDelta timestamp_offset_before_processing =
      *timestamp_offset_during_append_;

  // Calculate the new timestamp offset for audio/video tracks if the stream
  // parser has requested automatic updates.
  TimeDelta new_timestamp_offset = timestamp_offset_before_processing;
  if (auto_update_timestamp_offset_) {
    const bool have_audio_buffers = !audio_buffers.empty();
    const bool have_video_buffers = !video_buffers.empty();
    if (have_audio_buffers && have_video_buffers) {
      new_timestamp_offset +=
          std::min(EndTimestamp(audio_buffers), EndTimestamp(video_buffers));
    } else if (have_audio_buffers) {
      new_timestamp_offset += EndTimestamp(audio_buffers);
    } else if (have_video_buffers) {
      new_timestamp_offset += EndTimestamp(video_buffers);
    }
  }

  if (!frame_processor_->ProcessFrames(audio_buffers,
                                       video_buffers,
                                       text_map,
                                       append_window_start_during_append_,
                                       append_window_end_during_append_,
                                       &new_media_segment_,
                                       timestamp_offset_during_append_)) {
    return false;
  }

  // Only update the timestamp offset if the frame processor hasn't already.
  if (auto_update_timestamp_offset_ &&
      timestamp_offset_before_processing == *timestamp_offset_during_append_) {
    *timestamp_offset_during_append_ = new_timestamp_offset;
  }

  return true;
}

void SourceState::OnSourceInitDone(const StreamParser::InitParameters& params) {
  auto_update_timestamp_offset_ = params.auto_update_timestamp_offset;
  base::ResetAndReturn(&init_cb_).Run(params);
}

ChunkDemuxerStream::ChunkDemuxerStream(Type type,
                                       bool splice_frames_enabled)
    : type_(type),
      liveness_(DemuxerStream::LIVENESS_UNKNOWN),
      state_(UNINITIALIZED),
      splice_frames_enabled_(splice_frames_enabled),
      partial_append_window_trimming_enabled_(false) {
}

void ChunkDemuxerStream::StartReturningData() {
  DVLOG(1) << "ChunkDemuxerStream::StartReturningData()";
  base::AutoLock auto_lock(lock_);
  DCHECK(read_cb_.is_null());
  ChangeState_Locked(RETURNING_DATA_FOR_READS);
}

void ChunkDemuxerStream::AbortReads() {
  DVLOG(1) << "ChunkDemuxerStream::AbortReads()";
  base::AutoLock auto_lock(lock_);
  ChangeState_Locked(RETURNING_ABORT_FOR_READS);
  if (!read_cb_.is_null())
    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
}

void ChunkDemuxerStream::CompletePendingReadIfPossible() {
  base::AutoLock auto_lock(lock_);
  if (read_cb_.is_null())
    return;

  CompletePendingReadIfPossible_Locked();
}

void ChunkDemuxerStream::Shutdown() {
  DVLOG(1) << "ChunkDemuxerStream::Shutdown()";
  base::AutoLock auto_lock(lock_);
  ChangeState_Locked(SHUTDOWN);

  // Pass an end of stream buffer to the pending callback to signal that no more
  // data will be sent.
  if (!read_cb_.is_null()) {
    base::ResetAndReturn(&read_cb_).Run(DemuxerStream::kOk,
                                        StreamParserBuffer::CreateEOSBuffer());
  }
}

bool ChunkDemuxerStream::IsSeekWaitingForData() const {
  base::AutoLock auto_lock(lock_);

  // This method should not be called for text tracks. See the note in
  // SourceState::IsSeekWaitingForData().
  DCHECK_NE(type_, DemuxerStream::TEXT);

  return stream_->IsSeekPending();
}

void ChunkDemuxerStream::Seek(TimeDelta time) {
  DVLOG(1) << "ChunkDemuxerStream::Seek(" << time.InSecondsF() << ")";
  base::AutoLock auto_lock(lock_);
  DCHECK(read_cb_.is_null());
  DCHECK(state_ == UNINITIALIZED || state_ == RETURNING_ABORT_FOR_READS)
      << state_;

  stream_->Seek(time);
}

bool ChunkDemuxerStream::Append(const StreamParser::BufferQueue& buffers) {
  if (buffers.empty())
    return false;

  base::AutoLock auto_lock(lock_);
  DCHECK_NE(state_, SHUTDOWN);
  if (!stream_->Append(buffers)) {
    DVLOG(1) << "ChunkDemuxerStream::Append() : stream append failed";
    return false;
  }

  if (!read_cb_.is_null())
    CompletePendingReadIfPossible_Locked();

  return true;
}

void ChunkDemuxerStream::Remove(TimeDelta start, TimeDelta end,
                                TimeDelta duration) {
  base::AutoLock auto_lock(lock_);
  stream_->Remove(start, end, duration);
}

bool ChunkDemuxerStream::EvictCodedFrames(DecodeTimestamp media_time,
                                          size_t newDataSize) {
  base::AutoLock auto_lock(lock_);
  return stream_->GarbageCollectIfNeeded(media_time, newDataSize);
}

void ChunkDemuxerStream::OnSetDuration(TimeDelta duration) {
  base::AutoLock auto_lock(lock_);
  stream_->OnSetDuration(duration);
}

Ranges<TimeDelta> ChunkDemuxerStream::GetBufferedRanges(
    TimeDelta duration) const {
  base::AutoLock auto_lock(lock_);

  if (type_ == TEXT) {
    // Since text tracks are discontinuous and the lack of cues should not block
    // playback, report the buffered range for text tracks as [0, |duration|) so
    // that intesections with audio & video tracks are computed correctly when
    // no cues are present.
    Ranges<TimeDelta> text_range;
    text_range.Add(TimeDelta(), duration);
    return text_range;
  }

  Ranges<TimeDelta> range = stream_->GetBufferedTime();

  if (range.size() == 0u)
    return range;

  // Clamp the end of the stream's buffered ranges to fit within the duration.
  // This can be done by intersecting the stream's range with the valid time
  // range.
  Ranges<TimeDelta> valid_time_range;
  valid_time_range.Add(range.start(0), duration);
  return range.IntersectionWith(valid_time_range);
}

TimeDelta ChunkDemuxerStream::GetBufferedDuration() const {
  return stream_->GetBufferedDuration();
}

size_t ChunkDemuxerStream::GetBufferedSize() const {
  return stream_->GetBufferedSize();
}

void ChunkDemuxerStream::OnNewMediaSegment(DecodeTimestamp start_timestamp) {
  DVLOG(2) << "ChunkDemuxerStream::OnNewMediaSegment("
           << start_timestamp.InSecondsF() << ")";
  base::AutoLock auto_lock(lock_);
  stream_->OnNewMediaSegment(start_timestamp);
}

bool ChunkDemuxerStream::UpdateAudioConfig(
    const AudioDecoderConfig& config,
    const scoped_refptr<MediaLog>& media_log) {
  DCHECK(config.IsValidConfig());
  DCHECK_EQ(type_, AUDIO);
  base::AutoLock auto_lock(lock_);
  if (!stream_) {
    DCHECK_EQ(state_, UNINITIALIZED);

    // On platforms which support splice frames, enable splice frames and
    // partial append window support for most codecs (notably: not opus).
    const bool codec_supported = config.codec() == kCodecMP3 ||
                                 config.codec() == kCodecAAC ||
                                 config.codec() == kCodecVorbis;
    splice_frames_enabled_ = splice_frames_enabled_ && codec_supported;
    partial_append_window_trimming_enabled_ =
        splice_frames_enabled_ && codec_supported;

    stream_.reset(
        new SourceBufferStream(config, media_log, splice_frames_enabled_));
    return true;
  }

  return stream_->UpdateAudioConfig(config);
}

bool ChunkDemuxerStream::UpdateVideoConfig(
    const VideoDecoderConfig& config,
    const scoped_refptr<MediaLog>& media_log) {
  DCHECK(config.IsValidConfig());
  DCHECK_EQ(type_, VIDEO);
  base::AutoLock auto_lock(lock_);

  if (!stream_) {
    DCHECK_EQ(state_, UNINITIALIZED);
    stream_.reset(
        new SourceBufferStream(config, media_log, splice_frames_enabled_));
    return true;
  }

  return stream_->UpdateVideoConfig(config);
}

void ChunkDemuxerStream::UpdateTextConfig(
    const TextTrackConfig& config,
    const scoped_refptr<MediaLog>& media_log) {
  DCHECK_EQ(type_, TEXT);
  base::AutoLock auto_lock(lock_);
  DCHECK(!stream_);
  DCHECK_EQ(state_, UNINITIALIZED);
  stream_.reset(
      new SourceBufferStream(config, media_log, splice_frames_enabled_));
}

void ChunkDemuxerStream::MarkEndOfStream() {
  base::AutoLock auto_lock(lock_);
  stream_->MarkEndOfStream();
}

void ChunkDemuxerStream::UnmarkEndOfStream() {
  base::AutoLock auto_lock(lock_);
  stream_->UnmarkEndOfStream();
}

// DemuxerStream methods.
void ChunkDemuxerStream::Read(const ReadCB& read_cb) {
  base::AutoLock auto_lock(lock_);
  DCHECK_NE(state_, UNINITIALIZED);
  DCHECK(read_cb_.is_null());

  read_cb_ = BindToCurrentLoop(read_cb);
  CompletePendingReadIfPossible_Locked();
}

DemuxerStream::Type ChunkDemuxerStream::type() const { return type_; }

DemuxerStream::Liveness ChunkDemuxerStream::liveness() const {
  base::AutoLock auto_lock(lock_);
  return liveness_;
}

AudioDecoderConfig ChunkDemuxerStream::audio_decoder_config() {
  CHECK_EQ(type_, AUDIO);
  base::AutoLock auto_lock(lock_);
  return stream_->GetCurrentAudioDecoderConfig();
}

VideoDecoderConfig ChunkDemuxerStream::video_decoder_config() {
  CHECK_EQ(type_, VIDEO);
  base::AutoLock auto_lock(lock_);
  return stream_->GetCurrentVideoDecoderConfig();
}

bool ChunkDemuxerStream::SupportsConfigChanges() { return true; }

VideoRotation ChunkDemuxerStream::video_rotation() {
  return VIDEO_ROTATION_0;
}

TextTrackConfig ChunkDemuxerStream::text_track_config() {
  CHECK_EQ(type_, TEXT);
  base::AutoLock auto_lock(lock_);
  return stream_->GetCurrentTextTrackConfig();
}

void ChunkDemuxerStream::SetStreamMemoryLimit(size_t memory_limit) {
  stream_->set_memory_limit(memory_limit);
}

void ChunkDemuxerStream::SetLiveness(Liveness liveness) {
  base::AutoLock auto_lock(lock_);
  liveness_ = liveness;
}

void ChunkDemuxerStream::ChangeState_Locked(State state) {
  lock_.AssertAcquired();
  DVLOG(1) << "ChunkDemuxerStream::ChangeState_Locked() : "
           << "type " << type_
           << " - " << state_ << " -> " << state;
  state_ = state;
}

ChunkDemuxerStream::~ChunkDemuxerStream() {}

void ChunkDemuxerStream::CompletePendingReadIfPossible_Locked() {
  lock_.AssertAcquired();
  DCHECK(!read_cb_.is_null());

  DemuxerStream::Status status;
  scoped_refptr<StreamParserBuffer> buffer;

  switch (state_) {
    case UNINITIALIZED:
      NOTREACHED();
      return;
    case RETURNING_DATA_FOR_READS:
      switch (stream_->GetNextBuffer(&buffer)) {
        case SourceBufferStream::kSuccess:
          status = DemuxerStream::kOk;
          DVLOG(2) << __FUNCTION__ << ": returning kOk, type " << type_
                   << ", dts " << buffer->GetDecodeTimestamp().InSecondsF()
                   << ", pts " << buffer->timestamp().InSecondsF()
                   << ", dur " << buffer->duration().InSecondsF()
                   << ", key " << buffer->is_key_frame();
          break;
        case SourceBufferStream::kNeedBuffer:
          // Return early without calling |read_cb_| since we don't have
          // any data to return yet.
          DVLOG(2) << __FUNCTION__ << ": returning kNeedBuffer, type "
                   << type_;
          return;
        case SourceBufferStream::kEndOfStream:
          status = DemuxerStream::kOk;
          buffer = StreamParserBuffer::CreateEOSBuffer();
          DVLOG(2) << __FUNCTION__ << ": returning kOk with EOS buffer, type "
                   << type_;
          break;
        case SourceBufferStream::kConfigChange:
          status = kConfigChanged;
          buffer = NULL;
          DVLOG(2) << __FUNCTION__ << ": returning kConfigChange, type "
                   << type_;
          break;
      }
      break;
    case RETURNING_ABORT_FOR_READS:
      // Null buffers should be returned in this state since we are waiting
      // for a seek. Any buffers in the SourceBuffer should NOT be returned
      // because they are associated with the seek.
      status = DemuxerStream::kAborted;
      buffer = NULL;
      DVLOG(2) << __FUNCTION__ << ": returning kAborted, type " << type_;
      break;
    case SHUTDOWN:
      status = DemuxerStream::kOk;
      buffer = StreamParserBuffer::CreateEOSBuffer();
      DVLOG(2) << __FUNCTION__ << ": returning kOk with EOS buffer, type "
               << type_;
      break;
  }

  base::ResetAndReturn(&read_cb_).Run(status, buffer);
}

ChunkDemuxer::ChunkDemuxer(
    const base::Closure& open_cb,
    const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
    const scoped_refptr<MediaLog>& media_log,
    bool splice_frames_enabled)
    : state_(WAITING_FOR_INIT),
      cancel_next_seek_(false),
      host_(NULL),
      open_cb_(open_cb),
      encrypted_media_init_data_cb_(encrypted_media_init_data_cb),
      enable_text_(false),
      media_log_(media_log),
      duration_(kNoTimestamp()),
      user_specified_duration_(-1),
      liveness_(DemuxerStream::LIVENESS_UNKNOWN),
      splice_frames_enabled_(splice_frames_enabled) {
  DCHECK(!open_cb_.is_null());
  DCHECK(!encrypted_media_init_data_cb_.is_null());
}

std::string ChunkDemuxer::GetDisplayName() const {
  return "ChunkDemuxer";
}

void ChunkDemuxer::Initialize(
    DemuxerHost* host,
    const PipelineStatusCB& cb,
    bool enable_text_tracks) {
  DVLOG(1) << "Init()";

  base::AutoLock auto_lock(lock_);

  // The |init_cb_| must only be run after this method returns, so always post.
  init_cb_ = BindToCurrentLoop(cb);
  if (state_ == SHUTDOWN) {
    base::ResetAndReturn(&init_cb_).Run(DEMUXER_ERROR_COULD_NOT_OPEN);
    return;
  }
  DCHECK_EQ(state_, WAITING_FOR_INIT);
  host_ = host;
  enable_text_ = enable_text_tracks;

  ChangeState_Locked(INITIALIZING);

  base::ResetAndReturn(&open_cb_).Run();
}

void ChunkDemuxer::Stop() {
  DVLOG(1) << "Stop()";
  Shutdown();
}

void ChunkDemuxer::Seek(TimeDelta time, const PipelineStatusCB& cb) {
  DVLOG(1) << "Seek(" << time.InSecondsF() << ")";
  DCHECK(time >= TimeDelta());

  base::AutoLock auto_lock(lock_);
  DCHECK(seek_cb_.is_null());

  seek_cb_ = BindToCurrentLoop(cb);
  if (state_ != INITIALIZED && state_ != ENDED) {
    base::ResetAndReturn(&seek_cb_).Run(PIPELINE_ERROR_INVALID_STATE);
    return;
  }

  if (cancel_next_seek_) {
    cancel_next_seek_ = false;
    base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
    return;
  }

  SeekAllSources(time);
  StartReturningData();

  if (IsSeekWaitingForData_Locked()) {
    DVLOG(1) << "Seek() : waiting for more data to arrive.";
    return;
  }

  base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
}

// Demuxer implementation.
base::Time ChunkDemuxer::GetTimelineOffset() const {
  return timeline_offset_;
}

DemuxerStream* ChunkDemuxer::GetStream(DemuxerStream::Type type) {
  DCHECK_NE(type, DemuxerStream::TEXT);
  base::AutoLock auto_lock(lock_);
  if (type == DemuxerStream::VIDEO)
    return video_.get();

  if (type == DemuxerStream::AUDIO)
    return audio_.get();

  return NULL;
}

TimeDelta ChunkDemuxer::GetStartTime() const {
  return TimeDelta();
}

void ChunkDemuxer::StartWaitingForSeek(TimeDelta seek_time) {
  DVLOG(1) << "StartWaitingForSeek()";
  base::AutoLock auto_lock(lock_);
  DCHECK(state_ == INITIALIZED || state_ == ENDED || state_ == SHUTDOWN ||
         state_ == PARSE_ERROR) << state_;
  DCHECK(seek_cb_.is_null());

  if (state_ == SHUTDOWN || state_ == PARSE_ERROR)
    return;

  AbortPendingReads();
  SeekAllSources(seek_time);

  // Cancel state set in CancelPendingSeek() since we want to
  // accept the next Seek().
  cancel_next_seek_ = false;
}

void ChunkDemuxer::CancelPendingSeek(TimeDelta seek_time) {
  base::AutoLock auto_lock(lock_);
  DCHECK_NE(state_, INITIALIZING);
  DCHECK(seek_cb_.is_null() || IsSeekWaitingForData_Locked());

  if (cancel_next_seek_)
    return;

  AbortPendingReads();
  SeekAllSources(seek_time);

  if (seek_cb_.is_null()) {
    cancel_next_seek_ = true;
    return;
  }

  base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
}

ChunkDemuxer::Status ChunkDemuxer::AddId(const std::string& id,
                                         const std::string& type,
                                         std::vector<std::string>& codecs) {
  base::AutoLock auto_lock(lock_);

  if ((state_ != WAITING_FOR_INIT && state_ != INITIALIZING) || IsValidId(id))
    return kReachedIdLimit;

  bool has_audio = false;
  bool has_video = false;
  scoped_ptr<media::StreamParser> stream_parser(StreamParserFactory::Create(
      type, codecs, media_log_, &has_audio, &has_video));

  if (!stream_parser)
    return ChunkDemuxer::kNotSupported;

  if ((has_audio && !source_id_audio_.empty()) ||
      (has_video && !source_id_video_.empty()))
    return kReachedIdLimit;

  if (has_audio)
    source_id_audio_ = id;

  if (has_video)
    source_id_video_ = id;

  scoped_ptr<FrameProcessor> frame_processor(
      new FrameProcessor(base::Bind(&ChunkDemuxer::IncreaseDurationIfNecessary,
                                    base::Unretained(this)),
                         media_log_));

  scoped_ptr<SourceState> source_state(new SourceState(
      stream_parser.Pass(), frame_processor.Pass(),
      base::Bind(&ChunkDemuxer::CreateDemuxerStream, base::Unretained(this)),
      media_log_));

  SourceState::NewTextTrackCB new_text_track_cb;

  if (enable_text_) {
    new_text_track_cb = base::Bind(&ChunkDemuxer::OnNewTextTrack,
                                   base::Unretained(this));
  }

  source_state->Init(
      base::Bind(&ChunkDemuxer::OnSourceInitDone, base::Unretained(this)),
      has_audio, has_video, encrypted_media_init_data_cb_, new_text_track_cb);

  source_state_map_[id] = source_state.release();
  return kOk;
}

void ChunkDemuxer::RemoveId(const std::string& id) {
  base::AutoLock auto_lock(lock_);
  CHECK(IsValidId(id));

  delete source_state_map_[id];
  source_state_map_.erase(id);

  if (source_id_audio_ == id)
    source_id_audio_.clear();

  if (source_id_video_ == id)
    source_id_video_.clear();
}

Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges(const std::string& id) const {
  base::AutoLock auto_lock(lock_);
  DCHECK(!id.empty());

  SourceStateMap::const_iterator itr = source_state_map_.find(id);

  DCHECK(itr != source_state_map_.end());
  return itr->second->GetBufferedRanges(duration_, state_ == ENDED);
}

bool ChunkDemuxer::EvictCodedFrames(const std::string& id,
                                    base::TimeDelta currentMediaTime,
                                    size_t newDataSize) {
  DVLOG(1) << __FUNCTION__ << "(" << id << ")"
           << " media_time=" << currentMediaTime.InSecondsF()
           << " newDataSize=" << newDataSize;
  base::AutoLock auto_lock(lock_);

  // Note: The direct conversion from PTS to DTS is safe here, since we don't
  // need to know currentTime precisely for GC. GC only needs to know which GOP
  // currentTime points to.
  DecodeTimestamp media_time_dts =
      DecodeTimestamp::FromPresentationTime(currentMediaTime);

  DCHECK(!id.empty());
  SourceStateMap::const_iterator itr = source_state_map_.find(id);
  if (itr == source_state_map_.end()) {
    LOG(WARNING) << __FUNCTION__ << " stream " << id << " not found";
    return false;
  }
  return itr->second->EvictCodedFrames(media_time_dts, newDataSize);
}

void ChunkDemuxer::AppendData(
    const std::string& id,
    const uint8* data,
    size_t length,
    TimeDelta append_window_start,
    TimeDelta append_window_end,
    TimeDelta* timestamp_offset,
    const InitSegmentReceivedCB& init_segment_received_cb) {
  DVLOG(1) << "AppendData(" << id << ", " << length << ")";

  DCHECK(!id.empty());
  DCHECK(timestamp_offset);
  DCHECK(!init_segment_received_cb.is_null());

  Ranges<TimeDelta> ranges;

  {
    base::AutoLock auto_lock(lock_);
    DCHECK_NE(state_, ENDED);

    // Capture if any of the SourceBuffers are waiting for data before we start
    // parsing.
    bool old_waiting_for_data = IsSeekWaitingForData_Locked();

    if (length == 0u)
      return;

    DCHECK(data);

    switch (state_) {
      case INITIALIZING:
      case INITIALIZED:
        DCHECK(IsValidId(id));
        if (!source_state_map_[id]->Append(data, length,
                                           append_window_start,
                                           append_window_end,
                                           timestamp_offset,
                                           init_segment_received_cb)) {
          ReportError_Locked(PIPELINE_ERROR_DECODE);
          return;
        }
        break;

      case PARSE_ERROR:
        DVLOG(1) << "AppendData(): Ignoring data after a parse error.";
        return;

      case WAITING_FOR_INIT:
      case ENDED:
      case SHUTDOWN:
        DVLOG(1) << "AppendData(): called in unexpected state " << state_;
        return;
    }

    // Check to see if data was appended at the pending seek point. This
    // indicates we have parsed enough data to complete the seek.
    if (old_waiting_for_data && !IsSeekWaitingForData_Locked() &&
        !seek_cb_.is_null()) {
      base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
    }

    ranges = GetBufferedRanges_Locked();
  }

  for (size_t i = 0; i < ranges.size(); ++i)
    host_->AddBufferedTimeRange(ranges.start(i), ranges.end(i));
}

void ChunkDemuxer::Abort(const std::string& id,
                         TimeDelta append_window_start,
                         TimeDelta append_window_end,
                         TimeDelta* timestamp_offset) {
  DVLOG(1) << "Abort(" << id << ")";
  base::AutoLock auto_lock(lock_);
  DCHECK(!id.empty());
  CHECK(IsValidId(id));
  bool old_waiting_for_data = IsSeekWaitingForData_Locked();
  source_state_map_[id]->Abort(append_window_start,
                               append_window_end,
                               timestamp_offset);
  // Abort can possibly emit some buffers.
  // Need to check whether seeking can be completed.
  if (old_waiting_for_data && !IsSeekWaitingForData_Locked() &&
      !seek_cb_.is_null()) {
    base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
  }
}

void ChunkDemuxer::Remove(const std::string& id, TimeDelta start,
                          TimeDelta end) {
  DVLOG(1) << "Remove(" << id << ", " << start.InSecondsF()
           << ", " << end.InSecondsF() << ")";
  base::AutoLock auto_lock(lock_);

  DCHECK(!id.empty());
  CHECK(IsValidId(id));
  DCHECK(start >= base::TimeDelta()) << start.InSecondsF();
  DCHECK(start < end) << "start " << start.InSecondsF()
                      << " end " << end.InSecondsF();
  DCHECK(duration_ != kNoTimestamp());
  DCHECK(start <= duration_) << "start " << start.InSecondsF()
                             << " duration " << duration_.InSecondsF();

  if (start == duration_)
    return;

  source_state_map_[id]->Remove(start, end, duration_);
}

double ChunkDemuxer::GetDuration() {
  base::AutoLock auto_lock(lock_);
  return GetDuration_Locked();
}

double ChunkDemuxer::GetDuration_Locked() {
  lock_.AssertAcquired();
  if (duration_ == kNoTimestamp())
    return std::numeric_limits<double>::quiet_NaN();

  // Return positive infinity if the resource is unbounded.
  // http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#dom-media-duration
  if (duration_ == kInfiniteDuration())
    return std::numeric_limits<double>::infinity();

  if (user_specified_duration_ >= 0)
    return user_specified_duration_;

  return duration_.InSecondsF();
}

void ChunkDemuxer::SetDuration(double duration) {
  base::AutoLock auto_lock(lock_);
  DVLOG(1) << "SetDuration(" << duration << ")";
  DCHECK_GE(duration, 0);

  if (duration == GetDuration_Locked())
    return;

  // Compute & bounds check the TimeDelta representation of duration.
  // This can be different if the value of |duration| doesn't fit the range or
  // precision of TimeDelta.
  TimeDelta min_duration = TimeDelta::FromInternalValue(1);
  // Don't use TimeDelta::Max() here, as we want the largest finite time delta.
  TimeDelta max_duration = TimeDelta::FromInternalValue(kint64max - 1);
  double min_duration_in_seconds = min_duration.InSecondsF();
  double max_duration_in_seconds = max_duration.InSecondsF();

  TimeDelta duration_td;
  if (duration == std::numeric_limits<double>::infinity()) {
    duration_td = media::kInfiniteDuration();
  } else if (duration < min_duration_in_seconds) {
    duration_td = min_duration;
  } else if (duration > max_duration_in_seconds) {
    duration_td = max_duration;
  } else {
    duration_td = TimeDelta::FromMicroseconds(
        duration * base::Time::kMicrosecondsPerSecond);
  }

  DCHECK(duration_td > TimeDelta());

  user_specified_duration_ = duration;
  duration_ = duration_td;
  host_->SetDuration(duration_);

  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->OnSetDuration(duration_);
  }
}

bool ChunkDemuxer::IsParsingMediaSegment(const std::string& id) {
  base::AutoLock auto_lock(lock_);
  DVLOG(1) << "IsParsingMediaSegment(" << id << ")";
  CHECK(IsValidId(id));

  return source_state_map_[id]->parsing_media_segment();
}

void ChunkDemuxer::SetSequenceMode(const std::string& id,
                                   bool sequence_mode) {
  base::AutoLock auto_lock(lock_);
  DVLOG(1) << "SetSequenceMode(" << id << ", " << sequence_mode << ")";
  CHECK(IsValidId(id));
  DCHECK_NE(state_, ENDED);

  source_state_map_[id]->SetSequenceMode(sequence_mode);
}

void ChunkDemuxer::SetGroupStartTimestampIfInSequenceMode(
    const std::string& id,
    base::TimeDelta timestamp_offset) {
  base::AutoLock auto_lock(lock_);
  DVLOG(1) << "SetGroupStartTimestampIfInSequenceMode(" << id << ", "
           << timestamp_offset.InSecondsF() << ")";
  CHECK(IsValidId(id));
  DCHECK_NE(state_, ENDED);

  source_state_map_[id]->SetGroupStartTimestampIfInSequenceMode(
      timestamp_offset);
}


void ChunkDemuxer::MarkEndOfStream(PipelineStatus status) {
  DVLOG(1) << "MarkEndOfStream(" << status << ")";
  base::AutoLock auto_lock(lock_);
  DCHECK_NE(state_, WAITING_FOR_INIT);
  DCHECK_NE(state_, ENDED);

  if (state_ == SHUTDOWN || state_ == PARSE_ERROR)
    return;

  if (state_ == INITIALIZING) {
    ReportError_Locked(DEMUXER_ERROR_COULD_NOT_OPEN);
    return;
  }

  bool old_waiting_for_data = IsSeekWaitingForData_Locked();
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->MarkEndOfStream();
  }

  CompletePendingReadsIfPossible();

  // Give a chance to resume the pending seek process.
  if (status != PIPELINE_OK) {
    ReportError_Locked(status);
    return;
  }

  ChangeState_Locked(ENDED);
  DecreaseDurationIfNecessary();

  if (old_waiting_for_data && !IsSeekWaitingForData_Locked() &&
      !seek_cb_.is_null()) {
    base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
  }
}

void ChunkDemuxer::UnmarkEndOfStream() {
  DVLOG(1) << "UnmarkEndOfStream()";
  base::AutoLock auto_lock(lock_);
  DCHECK_EQ(state_, ENDED);

  ChangeState_Locked(INITIALIZED);

  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->UnmarkEndOfStream();
  }
}

void ChunkDemuxer::Shutdown() {
  DVLOG(1) << "Shutdown()";
  base::AutoLock auto_lock(lock_);

  if (state_ == SHUTDOWN)
    return;

  ShutdownAllStreams();

  ChangeState_Locked(SHUTDOWN);

  if(!seek_cb_.is_null())
    base::ResetAndReturn(&seek_cb_).Run(PIPELINE_ERROR_ABORT);
}

void ChunkDemuxer::SetMemoryLimits(DemuxerStream::Type type,
                                   size_t memory_limit) {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->SetMemoryLimits(type, memory_limit);
  }
}

void ChunkDemuxer::ChangeState_Locked(State new_state) {
  lock_.AssertAcquired();
  DVLOG(1) << "ChunkDemuxer::ChangeState_Locked() : "
           << state_ << " -> " << new_state;
  state_ = new_state;
}

ChunkDemuxer::~ChunkDemuxer() {
  DCHECK_NE(state_, INITIALIZED);

  STLDeleteValues(&source_state_map_);
}

void ChunkDemuxer::ReportError_Locked(PipelineStatus error) {
  DVLOG(1) << "ReportError_Locked(" << error << ")";
  lock_.AssertAcquired();
  DCHECK_NE(error, PIPELINE_OK);

  ChangeState_Locked(PARSE_ERROR);

  PipelineStatusCB cb;

  if (!init_cb_.is_null()) {
    std::swap(cb, init_cb_);
  } else {
    if (!seek_cb_.is_null())
      std::swap(cb, seek_cb_);

    ShutdownAllStreams();
  }

  if (!cb.is_null()) {
    cb.Run(error);
    return;
  }

  base::AutoUnlock auto_unlock(lock_);
  host_->OnDemuxerError(error);
}

bool ChunkDemuxer::IsSeekWaitingForData_Locked() const {
  lock_.AssertAcquired();
  for (SourceStateMap::const_iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    if (itr->second->IsSeekWaitingForData())
      return true;
  }

  return false;
}

void ChunkDemuxer::OnSourceInitDone(
    const StreamParser::InitParameters& params) {
  DVLOG(1) << "OnSourceInitDone(" << params.duration.InSecondsF() << ")";
  lock_.AssertAcquired();
  DCHECK_EQ(state_, INITIALIZING);
  if (!audio_ && !video_) {
    ReportError_Locked(DEMUXER_ERROR_COULD_NOT_OPEN);
    return;
  }

  if (params.duration != TimeDelta() && duration_ == kNoTimestamp())
    UpdateDuration(params.duration);

  if (!params.timeline_offset.is_null()) {
    if (!timeline_offset_.is_null() &&
        params.timeline_offset != timeline_offset_) {
      MEDIA_LOG(ERROR, media_log_)
          << "Timeline offset is not the same across all SourceBuffers.";
      ReportError_Locked(DEMUXER_ERROR_COULD_NOT_OPEN);
      return;
    }

    timeline_offset_ = params.timeline_offset;
  }

  if (params.liveness != DemuxerStream::LIVENESS_UNKNOWN) {
    if (audio_)
      audio_->SetLiveness(params.liveness);
    if (video_)
      video_->SetLiveness(params.liveness);
  }

  // Wait until all streams have initialized.
  if ((!source_id_audio_.empty() && !audio_) ||
      (!source_id_video_.empty() && !video_)) {
    return;
  }

  SeekAllSources(GetStartTime());
  StartReturningData();

  if (duration_ == kNoTimestamp())
    duration_ = kInfiniteDuration();

  // The demuxer is now initialized after the |start_timestamp_| was set.
  ChangeState_Locked(INITIALIZED);
  base::ResetAndReturn(&init_cb_).Run(PIPELINE_OK);
}

ChunkDemuxerStream*
ChunkDemuxer::CreateDemuxerStream(DemuxerStream::Type type) {
  switch (type) {
    case DemuxerStream::AUDIO:
      if (audio_)
        return NULL;
      audio_.reset(
          new ChunkDemuxerStream(DemuxerStream::AUDIO, splice_frames_enabled_));
      return audio_.get();
      break;
    case DemuxerStream::VIDEO:
      if (video_)
        return NULL;
      video_.reset(
          new ChunkDemuxerStream(DemuxerStream::VIDEO, splice_frames_enabled_));
      return video_.get();
      break;
    case DemuxerStream::TEXT: {
      return new ChunkDemuxerStream(DemuxerStream::TEXT,
                                    splice_frames_enabled_);
      break;
    }
    case DemuxerStream::UNKNOWN:
    case DemuxerStream::NUM_TYPES:
      NOTREACHED();
      return NULL;
  }
  NOTREACHED();
  return NULL;
}

void ChunkDemuxer::OnNewTextTrack(ChunkDemuxerStream* text_stream,
                                  const TextTrackConfig& config) {
  lock_.AssertAcquired();
  DCHECK_NE(state_, SHUTDOWN);
  host_->AddTextStream(text_stream, config);
}

bool ChunkDemuxer::IsValidId(const std::string& source_id) const {
  lock_.AssertAcquired();
  return source_state_map_.count(source_id) > 0u;
}

void ChunkDemuxer::UpdateDuration(TimeDelta new_duration) {
  DCHECK(duration_ != new_duration);
  user_specified_duration_ = -1;
  duration_ = new_duration;
  host_->SetDuration(new_duration);
}

void ChunkDemuxer::IncreaseDurationIfNecessary(TimeDelta new_duration) {
  DCHECK(new_duration != kNoTimestamp());
  DCHECK(new_duration != kInfiniteDuration());

  // Per April 1, 2014 MSE spec editor's draft:
  // https://dvcs.w3.org/hg/html-media/raw-file/d471a4412040/media-source/
  //     media-source.html#sourcebuffer-coded-frame-processing
  // 5. If the media segment contains data beyond the current duration, then run
  //    the duration change algorithm with new duration set to the maximum of
  //    the current duration and the group end timestamp.

  if (new_duration <= duration_)
    return;

  DVLOG(2) << __FUNCTION__ << ": Increasing duration: "
           << duration_.InSecondsF() << " -> " << new_duration.InSecondsF();

  UpdateDuration(new_duration);
}

void ChunkDemuxer::DecreaseDurationIfNecessary() {
  lock_.AssertAcquired();

  TimeDelta max_duration;

  for (SourceStateMap::const_iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    max_duration = std::max(max_duration,
                            itr->second->GetMaxBufferedDuration());
  }

  if (max_duration == TimeDelta())
    return;

  if (max_duration < duration_)
    UpdateDuration(max_duration);
}

Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges() const {
  base::AutoLock auto_lock(lock_);
  return GetBufferedRanges_Locked();
}

Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges_Locked() const {
  lock_.AssertAcquired();

  bool ended = state_ == ENDED;
  // TODO(acolwell): When we start allowing SourceBuffers that are not active,
  // we'll need to update this loop to only add ranges from active sources.
  RangesList ranges_list;
  for (SourceStateMap::const_iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    ranges_list.push_back(itr->second->GetBufferedRanges(duration_, ended));
  }

  return ComputeIntersection(ranges_list, ended);
}

void ChunkDemuxer::StartReturningData() {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->StartReturningData();
  }
}

void ChunkDemuxer::AbortPendingReads() {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->AbortReads();
  }
}

void ChunkDemuxer::SeekAllSources(TimeDelta seek_time) {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->Seek(seek_time);
  }
}

void ChunkDemuxer::CompletePendingReadsIfPossible() {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->CompletePendingReadIfPossible();
  }
}

void ChunkDemuxer::ShutdownAllStreams() {
  for (SourceStateMap::iterator itr = source_state_map_.begin();
       itr != source_state_map_.end(); ++itr) {
    itr->second->Shutdown();
  }
}

}  // namespace media