palemoon27/dom/media/mediasource/MediaSourceDecoder.cpp

/* -*- mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "MediaSourceDecoder.h"

#include "prlog.h"
#include "mozilla/dom/HTMLMediaElement.h"
#include "MediaDecoderStateMachine.h"
#include "MediaSource.h"
#include "MediaSourceReader.h"
#include "MediaSourceResource.h"
#include "MediaSourceUtils.h"
#include "SourceBufferDecoder.h"
#include "VideoUtils.h"
#include "MediaFormatReader.h"
#include "MediaSourceDemuxer.h"
#include <algorithm>

extern PRLogModuleInfo* GetMediaSourceLog();

#define MSE_DEBUG(arg, ...) PR_LOG(GetMediaSourceLog(), PR_LOG_DEBUG, ("MediaSourceDecoder(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))
#define MSE_DEBUGV(arg, ...) PR_LOG(GetMediaSourceLog(), PR_LOG_DEBUG + 1, ("MediaSourceDecoder(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))

using namespace mozilla::media;

namespace mozilla {

class SourceBufferDecoder;

MediaSourceDecoder::MediaSourceDecoder(dom::HTMLMediaElement* aElement)
  : mMediaSource(nullptr)
  , mIsUsingFormatReader(Preferences::GetBool("media.mediasource.format-reader", false))
  , mEnded(false)
{
  SetExplicitDuration(UnspecifiedNaN<double>());
  Init(aElement);
}

MediaDecoder*
MediaSourceDecoder::Clone()
{
  // TODO: Sort out cloning.
  return nullptr;
}

MediaDecoderStateMachine*
MediaSourceDecoder::CreateStateMachine()
{
  if (mIsUsingFormatReader) {
    mDemuxer = new MediaSourceDemuxer();
    mReader = new MediaFormatReader(this, mDemuxer);
  } else {
    mReader = new MediaSourceReader(this);
  }
  return new MediaDecoderStateMachine(this, mReader);
}

nsresult
MediaSourceDecoder::Load(nsIStreamListener**, MediaDecoder*)
{
  MOZ_ASSERT(!GetStateMachine());
  SetStateMachine(CreateStateMachine());
  if (!GetStateMachine()) {
    NS_WARNING("Failed to create state machine!");
    return NS_ERROR_FAILURE;
  }

  nsresult rv = GetStateMachine()->Init(nullptr);
  NS_ENSURE_SUCCESS(rv, rv);

  SetStateMachineParameters();
  return ScheduleStateMachineThread();
}

media::TimeIntervals
MediaSourceDecoder::GetSeekable()
{
  MOZ_ASSERT(NS_IsMainThread());
  if (!mMediaSource) {
    NS_WARNING("MediaSource element isn't attached");
    return media::TimeIntervals::Invalid();
  }

  media::TimeIntervals seekable;
  double duration = mMediaSource->Duration();
  if (IsNaN(duration)) {
    // Return empty range.
  } else if (duration > 0 && mozilla::IsInfinite(duration)) {
    media::TimeIntervals buffered = mReader->GetBuffered();

    // 1. If live seekable range is not empty:
    if (mMediaSource->HasLiveSeekableRange()) {
      // 1. Let union ranges be the union of live seekable range and the
      // HTMLMediaElement.buffered attribute.
      media::TimeIntervals unionRanges =
        buffered + mMediaSource->LiveSeekableRange();
      // 2. Return a single range with a start time equal to the earliest start
      // time in union ranges and an end time equal to the highest end time in
      // union ranges and abort these steps.
      seekable +=
        media::TimeInterval(unionRanges.GetStart(), unionRanges.GetEnd());
      return seekable;
    }

    if (buffered.Length()) {
      seekable +=
        media::TimeInterval(media::TimeUnit::FromSeconds(0), buffered.GetEnd());
    }
  } else {
    seekable += media::TimeInterval(media::TimeUnit::FromSeconds(0),
                                    media::TimeUnit::FromSeconds(duration));
  }
  MSE_DEBUG("ranges=%s", DumpTimeRanges(seekable).get());
  return seekable;
}

void
MediaSourceDecoder::Shutdown()
{
  MSE_DEBUG("Shutdown");
  // Detach first so that TrackBuffers are unused on the main thread when
  // shut down on the decode task queue.
  if (mMediaSource) {
    mMediaSource->Detach();
  }
  mDemuxer = nullptr;

  MediaDecoder::Shutdown();
  // Kick WaitForData out of its slumber.
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  mon.NotifyAll();
}

/*static*/
already_AddRefed<MediaResource>
MediaSourceDecoder::CreateResource(nsIPrincipal* aPrincipal)
{
  return nsRefPtr<MediaResource>(new MediaSourceResource(aPrincipal)).forget();
}

void
MediaSourceDecoder::AttachMediaSource(dom::MediaSource* aMediaSource)
{
  MOZ_ASSERT(!mMediaSource && !GetStateMachine() && NS_IsMainThread());
  mMediaSource = aMediaSource;
}

void
MediaSourceDecoder::DetachMediaSource()
{
  MOZ_ASSERT(mMediaSource && NS_IsMainThread());
  mMediaSource = nullptr;
}

already_AddRefed<SourceBufferDecoder>
MediaSourceDecoder::CreateSubDecoder(const nsACString& aType, int64_t aTimestampOffset)
{
  MOZ_ASSERT(mReader && !mIsUsingFormatReader);
  return GetReader()->CreateSubDecoder(aType, aTimestampOffset);
}

void
MediaSourceDecoder::AddTrackBuffer(TrackBuffer* aTrackBuffer)
{
  MOZ_ASSERT(mReader && !mIsUsingFormatReader);
  GetReader()->AddTrackBuffer(aTrackBuffer);
}

void
MediaSourceDecoder::RemoveTrackBuffer(TrackBuffer* aTrackBuffer)
{
  MOZ_ASSERT(mReader && !mIsUsingFormatReader);
  GetReader()->RemoveTrackBuffer(aTrackBuffer);
}

void
MediaSourceDecoder::OnTrackBufferConfigured(TrackBuffer* aTrackBuffer, const MediaInfo& aInfo)
{
  MOZ_ASSERT(mReader && !mIsUsingFormatReader);
  GetReader()->OnTrackBufferConfigured(aTrackBuffer, aInfo);
}

void
MediaSourceDecoder::Ended(bool aEnded)
{
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  static_cast<MediaSourceResource*>(GetResource())->SetEnded(aEnded);
  if (!mIsUsingFormatReader) {
    GetReader()->Ended(aEnded);
  }
  mEnded = true;
  mon.NotifyAll();
}

bool
MediaSourceDecoder::IsExpectingMoreData()
{
  return !mEnded;
}

void
MediaSourceDecoder::SetInitialDuration(int64_t aDuration)
{
  MOZ_ASSERT(NS_IsMainThread());
  // Only use the decoded duration if one wasn't already
  // set.
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  if (!mMediaSource || !IsNaN(ExplicitDuration())) {
    return;
  }
  double duration = aDuration;
  // A duration of -1 is +Infinity.
  if (aDuration >= 0) {
    duration /= USECS_PER_S;
  }
  SetMediaSourceDuration(duration, MSRangeRemovalAction::SKIP);
}

void
MediaSourceDecoder::SetMediaSourceDuration(double aDuration, MSRangeRemovalAction aAction)
{
  MOZ_ASSERT(NS_IsMainThread());
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  double oldDuration = ExplicitDuration();
  if (aDuration >= 0) {
    int64_t checkedDuration;
    if (NS_FAILED(SecondsToUsecs(aDuration, checkedDuration))) {
      // INT64_MAX is used as infinity by the state machine.
      // We want a very bigger number, but not infinity.
      checkedDuration = INT64_MAX - 1;
    }
    SetExplicitDuration(aDuration);
  } else {
    SetExplicitDuration(PositiveInfinity<double>());
  }
  if (!mIsUsingFormatReader && GetReader()) {
    GetReader()->SetMediaSourceDuration(ExplicitDuration());
  }
  MediaDecoder::DurationChanged(TimeUnit::FromSeconds(ExplicitDuration()));
  if (mMediaSource && aAction != MSRangeRemovalAction::SKIP) {
    mMediaSource->DurationChange(oldDuration, aDuration);
  }
}

double
MediaSourceDecoder::GetMediaSourceDuration()
{
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  return ExplicitDuration();
}

void
MediaSourceDecoder::NotifyTimeRangesChanged()
{
  MOZ_ASSERT(mReader && !mIsUsingFormatReader);
  GetReader()->NotifyTimeRangesChanged();
}

void
MediaSourceDecoder::PrepareReaderInitialization()
{
  if (mIsUsingFormatReader) {
    return;
  }
  MOZ_ASSERT(mReader);
  GetReader()->PrepareInitialization();
}

void
MediaSourceDecoder::GetMozDebugReaderData(nsAString& aString)
{
  if (mIsUsingFormatReader) {
    return;
  }
  GetReader()->GetMozDebugReaderData(aString);
}

bool
MediaSourceDecoder::IsActiveReader(MediaDecoderReader* aReader)
{
  return !mIsUsingFormatReader && GetReader()->IsActiveReader(aReader);
}

double
MediaSourceDecoder::GetDuration()
{
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
  return ExplicitDuration();
}

MediaDecoderOwner::NextFrameStatus
MediaSourceDecoder::NextFrameBufferedStatus()
{
  MOZ_ASSERT(NS_IsMainThread());

  if (!mMediaSource ||
      mMediaSource->ReadyState() == dom::MediaSourceReadyState::Closed) {
    return MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE;
  }

  // Next frame hasn't been decoded yet.
  // Use the buffered range to consider if we have the next frame available.
  TimeUnit currentPosition = TimeUnit::FromMicroseconds(CurrentPosition());
  TimeInterval interval(currentPosition,
                        currentPosition + media::TimeUnit::FromMicroseconds(DEFAULT_NEXT_FRAME_AVAILABLE_BUFFERED),
                        MediaSourceDemuxer::EOS_FUZZ);
  return GetBuffered().Contains(interval)
    ? MediaDecoderOwner::NEXT_FRAME_AVAILABLE
    : MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE;
}

bool
MediaSourceDecoder::CanPlayThrough()
{
  MOZ_ASSERT(NS_IsMainThread());
  if (IsNaN(mMediaSource->Duration())) {
    // Don't have any data yet.
    return false;
  }
  TimeUnit duration = TimeUnit::FromSeconds(mMediaSource->Duration());
  TimeUnit currentPosition = TimeUnit::FromMicroseconds(CurrentPosition());
  if (duration <= currentPosition) {
    return true;
  }
  // If we have data up to the mediasource's duration or 30s ahead, we can
  // assume that we can play without interruption.
  TimeUnit timeAhead =
    std::min(duration, currentPosition + TimeUnit::FromSeconds(30));
  TimeInterval interval(currentPosition,
                        timeAhead,
                        MediaSourceDemuxer::EOS_FUZZ);
  return GetBuffered().Contains(interval);
}

already_AddRefed<SourceBufferDecoder>
MediaSourceDecoder::SelectDecoder(int64_t aTarget,
                                  int64_t aTolerance,
                                  const nsTArray<nsRefPtr<SourceBufferDecoder>>& aTrackDecoders)
{
  MOZ_ASSERT(!mIsUsingFormatReader);
  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());

  media::TimeUnit target{media::TimeUnit::FromMicroseconds(aTarget)};
  media::TimeUnit tolerance{media::TimeUnit::FromMicroseconds(aTolerance + aTarget)};

  // aTolerance gives a slight bias toward the start of a range only.
  // Consider decoders in order of newest to oldest, as a newer decoder
  // providing a given buffered range is expected to replace an older one.
  for (int32_t i = aTrackDecoders.Length() - 1; i >= 0; --i) {
    nsRefPtr<SourceBufferDecoder> newDecoder = aTrackDecoders[i];

    media::TimeIntervals ranges = newDecoder->GetBuffered();
    for (uint32_t j = 0; j < ranges.Length(); j++) {
      if (target < ranges.End(j) && tolerance >= ranges.Start(j)) {
        return newDecoder.forget();
      }
    }

    MSE_DEBUGV("SelectDecoder(%lld fuzz:%lld) newDecoder=%p (%d/%d) target not in ranges=%s",
               aTarget, aTolerance, newDecoder.get(), i+1,
               aTrackDecoders.Length(), DumpTimeRanges(ranges).get());
  }

  return nullptr;
}

#undef MSE_DEBUG
#undef MSE_DEBUGV

} // namespace mozilla