/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/

/* 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 "MediaStreamGraphImpl.h"

#include "MediaStreamListener.h"

#include "mozilla/MathAlgorithms.h"

#include "mozilla/Unused.h"

#include "AudioSegment.h"

#include "mozilla/Logging.h"

#include "mozilla/Attributes.h"

#include "AudioCaptureStream.h"

#include "ImageContainer.h"

#include "AudioNodeEngine.h"

#include "AudioNodeStream.h"

#include "AudioNodeExternalInputStream.h"

#include "webaudio/MediaStreamAudioDestinationNode.h"

#include <algorithm>

#include "DOMMediaStream.h"

using namespace mozilla::layers;

using namespace mozilla::dom;

using namespace mozilla::gfx;

namespace mozilla

{

// We are mixing to mono until PeerConnection can accept stereo

static const uint32_t MONO = 1;

AudioCaptureStream::AudioCaptureStream(TrackID aTrackId)

  : ProcessedMediaStream()

  , mTrackId(aTrackId)

  , mStarted(false)

  , mTrackCreated(false)

{

  MOZ_ASSERT(NS_IsMainThread());

  MOZ_COUNT_CTOR(AudioCaptureStream);

  mMixer.AddCallback(this);

}

AudioCaptureStream::~AudioCaptureStream()

{

  MOZ_COUNT_DTOR(AudioCaptureStream);

  mMixer.RemoveCallback(this);

}

void

AudioCaptureStream::Start()

{

  class Message : public ControlMessage {

  public:

    explicit Message(AudioCaptureStream* aStream)

      : ControlMessage(aStream), mStream(aStream) {}

    virtual void Run()

    {

      mStream->mStarted = true;

    }

  protected:

    AudioCaptureStream* mStream;

  };

  GraphImpl()->AppendMessage(MakeUnique<Message>(this));

}

void

AudioCaptureStream::ProcessInput(GraphTime aFrom, GraphTime aTo,

                                 uint32_t aFlags)

{

  if (!mStarted) {

    return;

  }

  uint32_t inputCount = mInputs.Length();

  StreamTracks::Track* track = EnsureTrack(mTrackId);

  // Notify the DOM everything is in order.

  if (!mTrackCreated) {

    for (uint32_t i = 0; i < mListeners.Length(); i++) {

      MediaStreamListener* l = mListeners[i];

      AudioSegment tmp;

      l->NotifyQueuedTrackChanges(

        Graph(), mTrackId, 0, TrackEventCommand::TRACK_EVENT_CREATED, tmp);

      l->NotifyFinishedTrackCreation(Graph());

    }

    mTrackCreated = true;

  }

  if (IsFinishedOnGraphThread()) {

    return;

  }

  // If the captured stream is connected back to a object on the page (be it an

  // HTMLMediaElement with a stream as source, or an AudioContext), a cycle

  // situation occur. This can work if it's an AudioContext with at least one

  // DelayNode, but the MSG will mute the whole cycle otherwise.

  if (InMutedCycle() || inputCount == 0) {

    track->Get<AudioSegment>()->AppendNullData(aTo - aFrom);

  } else {

    // We mix down all the tracks of all inputs, to a stereo track. Everything

    // is {up,down}-mixed to stereo.

    mMixer.StartMixing();

    AudioSegment output;

    for (uint32_t i = 0; i < inputCount; i++) {

      MediaStream* s = mInputs[i]->GetSource();

      StreamTracks::TrackIter track(s->GetStreamTracks(), MediaSegment::AUDIO);

      if (track.IsEnded()) {

        // No tracks for this input. Still we append data to trigger the mixer.

        AudioSegment toMix;

        toMix.AppendNullData(aTo - aFrom);

        toMix.Mix(mMixer, MONO, Graph()->GraphRate());

      }

      for (; !track.IsEnded(); track.Next()) {

        AudioSegment* inputSegment = track->Get<AudioSegment>();

        StreamTime inputStart = s->GraphTimeToStreamTimeWithBlocking(aFrom);

        StreamTime inputEnd = s->GraphTimeToStreamTimeWithBlocking(aTo);

        AudioSegment toMix;

        if (track->IsEnded() && inputSegment->GetDuration() <= inputStart) {

          toMix.AppendNullData(aTo - aFrom);

        } else {

          toMix.AppendSlice(*inputSegment, inputStart, inputEnd);

          // Care for streams blocked in the [aTo, aFrom] range.

          if (inputEnd - inputStart < aTo - aFrom) {

            toMix.AppendNullData((aTo - aFrom) - (inputEnd - inputStart));

          }

        }

        toMix.Mix(mMixer, MONO, Graph()->GraphRate());

      }

    }

    // This calls MixerCallback below

    mMixer.FinishMixing();

  }

  // Regardless of the status of the input tracks, we go foward.

  mTracks.AdvanceKnownTracksTime(GraphTimeToStreamTimeWithBlocking((aTo)));

}

void

AudioCaptureStream::MixerCallback(AudioDataValue* aMixedBuffer,

                                  AudioSampleFormat aFormat, uint32_t aChannels,

                                  uint32_t aFrames, uint32_t aSampleRate)

{

  AutoTArray<nsTArray<AudioDataValue>, MONO> output;

  AutoTArray<const AudioDataValue*, MONO> bufferPtrs;

  output.SetLength(MONO);

  bufferPtrs.SetLength(MONO);

  uint32_t written = 0;

  // We need to copy here, because the mixer will reuse the storage, we should

  // not hold onto it. Buffers are in planar format.

  for (uint32_t channel = 0; channel < aChannels; channel++) {

    AudioDataValue* out = output[channel].AppendElements(aFrames);

    PodCopy(out, aMixedBuffer + written, aFrames);

    bufferPtrs[channel] = out;

    written += aFrames;

  }

  AudioChunk chunk;

  chunk.mBuffer = new mozilla::SharedChannelArrayBuffer<AudioDataValue>(&output);

  chunk.mDuration = aFrames;

  chunk.mBufferFormat = aFormat;

  chunk.mChannelData.SetLength(MONO);

  for (uint32_t channel = 0; channel < aChannels; channel++) {

    chunk.mChannelData[channel] = bufferPtrs[channel];

  }

  // Now we have mixed data, simply append it to out track.

  EnsureTrack(mTrackId)->Get<AudioSegment>()->AppendAndConsumeChunk(&chunk);

}

}