gecko-dev/dom/media/webaudio/MediaBufferDecoder.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 "MediaBufferDecoder.h"
#include "BufferDecoder.h"
#include "mozilla/dom/AudioContextBinding.h"
#include "mozilla/dom/ScriptSettings.h"
#include <speex/speex_resampler.h>
#include "nsXPCOMCIDInternal.h"
#include "nsComponentManagerUtils.h"
#include "MediaDecoderReader.h"
#include "BufferMediaResource.h"
#include "DecoderTraits.h"
#include "AudioContext.h"
#include "AudioBuffer.h"
#include "nsAutoPtr.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIScriptError.h"
#include "nsMimeTypes.h"
#include "WebAudioUtils.h"
#include "mozilla/dom/Promise.h"
#ifdef XP_WIN
#include "ThreadPoolCOMListener.h"
#endif

namespace mozilla {

NS_IMPL_CYCLE_COLLECTION_CLASS(WebAudioDecodeJob)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(WebAudioDecodeJob)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mContext)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOutput)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSuccessCallback)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mFailureCallback)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(WebAudioDecodeJob)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mContext)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOutput)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSuccessCallback)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFailureCallback)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(WebAudioDecodeJob)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WebAudioDecodeJob, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WebAudioDecodeJob, Release)

using namespace dom;

class ReportResultTask : public nsRunnable
{
public:
  ReportResultTask(WebAudioDecodeJob& aDecodeJob,
                   WebAudioDecodeJob::ResultFn aFunction,
                   WebAudioDecodeJob::ErrorCode aErrorCode)
    : mDecodeJob(aDecodeJob)
    , mFunction(aFunction)
    , mErrorCode(aErrorCode)
  {
    MOZ_ASSERT(aFunction);
  }

  NS_IMETHOD Run()
  {
    MOZ_ASSERT(NS_IsMainThread());

    (mDecodeJob.*mFunction)(mErrorCode);

    return NS_OK;
  }

private:
  // Note that the mDecodeJob member will probably die when mFunction is run.
  // Therefore, it is not safe to do anything fancy with it in this class.
  // Really, this class is only used because nsRunnableMethod doesn't support
  // methods accepting arguments.
  WebAudioDecodeJob& mDecodeJob;
  WebAudioDecodeJob::ResultFn mFunction;
  WebAudioDecodeJob::ErrorCode mErrorCode;
};

MOZ_BEGIN_ENUM_CLASS(PhaseEnum, int)
  Decode,
  AllocateBuffer,
  Done
MOZ_END_ENUM_CLASS(PhaseEnum)

class MediaDecodeTask : public nsRunnable
{
public:
  MediaDecodeTask(const char* aContentType, uint8_t* aBuffer,
                  uint32_t aLength,
                  WebAudioDecodeJob& aDecodeJob,
                  nsIThreadPool* aThreadPool)
    : mContentType(aContentType)
    , mBuffer(aBuffer)
    , mLength(aLength)
    , mDecodeJob(aDecodeJob)
    , mPhase(PhaseEnum::Decode)
    , mThreadPool(aThreadPool)
  {
    MOZ_ASSERT(aBuffer);
    MOZ_ASSERT(NS_IsMainThread());

    nsCOMPtr<nsPIDOMWindow> pWindow = do_QueryInterface(mDecodeJob.mContext->GetParentObject());
    nsCOMPtr<nsIScriptObjectPrincipal> scriptPrincipal =
      do_QueryInterface(pWindow);
    if (scriptPrincipal) {
      mPrincipal = scriptPrincipal->GetPrincipal();
    }
  }

  NS_IMETHOD Run();
  bool CreateReader();

private:
  void ReportFailureOnMainThread(WebAudioDecodeJob::ErrorCode aErrorCode) {
    if (NS_IsMainThread()) {
      Cleanup();
      mDecodeJob.OnFailure(aErrorCode);
    } else {
      // Take extra care to cleanup on the main thread
      NS_DispatchToMainThread(NS_NewRunnableMethod(this, &MediaDecodeTask::Cleanup));

      nsCOMPtr<nsIRunnable> event =
        new ReportResultTask(mDecodeJob, &WebAudioDecodeJob::OnFailure, aErrorCode);
      NS_DispatchToMainThread(event);
    }
  }

  void Decode();
  void AllocateBuffer();
  void CallbackTheResult();

  void Cleanup()
  {
    MOZ_ASSERT(NS_IsMainThread());
    // MediaDecoderReader expects that BufferDecoder is alive.
    // Destruct MediaDecoderReader first.
    mDecoderReader->BreakCycles();
    mDecoderReader = nullptr;
    mBufferDecoder = nullptr;
    JS_free(nullptr, mBuffer);
  }

private:
  nsCString mContentType;
  uint8_t* mBuffer;
  uint32_t mLength;
  WebAudioDecodeJob& mDecodeJob;
  PhaseEnum mPhase;
  nsCOMPtr<nsIThreadPool> mThreadPool;
  nsCOMPtr<nsIPrincipal> mPrincipal;
  nsRefPtr<BufferDecoder> mBufferDecoder;
  nsRefPtr<MediaDecoderReader> mDecoderReader;
};

NS_IMETHODIMP
MediaDecodeTask::Run()
{
  MOZ_ASSERT(mBufferDecoder);
  MOZ_ASSERT(mDecoderReader);
  switch (mPhase) {
  case PhaseEnum::Decode:
    Decode();
    break;
  case PhaseEnum::AllocateBuffer:
    AllocateBuffer();
    break;
  case PhaseEnum::Done:
    break;
  }

  return NS_OK;
}

bool
MediaDecodeTask::CreateReader()
{
  MOZ_ASSERT(NS_IsMainThread());

  nsRefPtr<BufferMediaResource> resource =
    new BufferMediaResource(static_cast<uint8_t*> (mBuffer),
                            mLength, mPrincipal, mContentType);

  MOZ_ASSERT(!mBufferDecoder);
  mBufferDecoder = new BufferDecoder(resource);

  // If you change this list to add support for new decoders, please consider
  // updating HTMLMediaElement::CreateDecoder as well.

  mDecoderReader = DecoderTraits::CreateReader(mContentType, mBufferDecoder);

  if (!mDecoderReader) {
    return false;
  }

  nsresult rv = mDecoderReader->Init(nullptr);
  if (NS_FAILED(rv)) {
    return false;
  }

  return true;
}

class AutoResampler {
public:
  AutoResampler()
    : mResampler(nullptr)
  {}
  ~AutoResampler()
  {
    if (mResampler) {
      speex_resampler_destroy(mResampler);
    }
  }
  operator SpeexResamplerState*() const
  {
    MOZ_ASSERT(mResampler);
    return mResampler;
  }
  void operator=(SpeexResamplerState* aResampler)
  {
    mResampler = aResampler;
  }

private:
  SpeexResamplerState* mResampler;
};

void
MediaDecodeTask::Decode()
{
  MOZ_ASSERT(!NS_IsMainThread());

  mBufferDecoder->BeginDecoding(NS_GetCurrentThread());

  // Tell the decoder reader that we are not going to play the data directly,
  // and that we should not reject files with more channels than the audio
  // bakend support.
  mDecoderReader->SetIgnoreAudioOutputFormat();

  MediaInfo mediaInfo;
  nsAutoPtr<MetadataTags> tags;
  nsresult rv = mDecoderReader->ReadMetadata(&mediaInfo, getter_Transfers(tags));
  if (NS_FAILED(rv)) {
    mDecoderReader->Shutdown();
    ReportFailureOnMainThread(WebAudioDecodeJob::InvalidContent);
    return;
  }

  if (!mDecoderReader->HasAudio()) {
    mDecoderReader->Shutdown();
    ReportFailureOnMainThread(WebAudioDecodeJob::NoAudio);
    return;
  }

  MediaQueue<AudioData> audioQueue;
  nsRefPtr<AudioDecodeRendezvous> barrier(new AudioDecodeRendezvous(mDecoderReader));
  while (1) {
    nsRefPtr<AudioData> audio;
    if (NS_FAILED(barrier->RequestAndWait(audio))) {
      mDecoderReader->Shutdown();
      ReportFailureOnMainThread(WebAudioDecodeJob::InvalidContent);
      return;
    }
    if (!audio) {
      // End of stream.
      break;
    }
    audioQueue.Push(audio);
  }
  mDecoderReader->Shutdown();

  uint32_t frameCount = audioQueue.FrameCount();
  uint32_t channelCount = mediaInfo.mAudio.mChannels;
  uint32_t sampleRate = mediaInfo.mAudio.mRate;

  if (!frameCount || !channelCount || !sampleRate) {
    ReportFailureOnMainThread(WebAudioDecodeJob::InvalidContent);
    return;
  }

  const uint32_t destSampleRate = mDecodeJob.mContext->SampleRate();
  AutoResampler resampler;

  uint32_t resampledFrames = frameCount;
  if (sampleRate != destSampleRate) {
    resampledFrames = static_cast<uint32_t>(
        static_cast<uint64_t>(destSampleRate) *
        static_cast<uint64_t>(frameCount) /
        static_cast<uint64_t>(sampleRate)
      );

    resampler = speex_resampler_init(channelCount,
                                     sampleRate,
                                     destSampleRate,
                                     SPEEX_RESAMPLER_QUALITY_DEFAULT, nullptr);
    speex_resampler_skip_zeros(resampler);
    resampledFrames += speex_resampler_get_output_latency(resampler);
  }

  // Allocate the channel buffers.  Note that if we end up resampling, we may
  // write fewer bytes than mResampledFrames to the output buffer, in which
  // case mWriteIndex will tell us how many valid samples we have.
  static const fallible_t fallible = fallible_t();
  bool memoryAllocationSuccess = true;
  if (!mDecodeJob.mChannelBuffers.SetLength(channelCount)) {
    memoryAllocationSuccess = false;
  } else {
    for (uint32_t i = 0; i < channelCount; ++i) {
      mDecodeJob.mChannelBuffers[i] = new(fallible) float[resampledFrames];
      if (!mDecodeJob.mChannelBuffers[i]) {
        memoryAllocationSuccess = false;
        break;
      }
    }
  }
  if (!memoryAllocationSuccess) {
    ReportFailureOnMainThread(WebAudioDecodeJob::UnknownError);
    return;
  }

  nsRefPtr<AudioData> audioData;
  while ((audioData = audioQueue.PopFront())) {
    audioData->EnsureAudioBuffer(); // could lead to a copy :(
    AudioDataValue* bufferData = static_cast<AudioDataValue*>
      (audioData->mAudioBuffer->Data());

    if (sampleRate != destSampleRate) {
      const uint32_t maxOutSamples = resampledFrames - mDecodeJob.mWriteIndex;

      for (uint32_t i = 0; i < audioData->mChannels; ++i) {
        uint32_t inSamples = audioData->mFrames;
        uint32_t outSamples = maxOutSamples;

        WebAudioUtils::SpeexResamplerProcess(
            resampler, i, &bufferData[i * audioData->mFrames], &inSamples,
            mDecodeJob.mChannelBuffers[i] + mDecodeJob.mWriteIndex,
            &outSamples);

        if (i == audioData->mChannels - 1) {
          mDecodeJob.mWriteIndex += outSamples;
          MOZ_ASSERT(mDecodeJob.mWriteIndex <= resampledFrames);
          MOZ_ASSERT(inSamples == audioData->mFrames);
        }
      }
    } else {
      for (uint32_t i = 0; i < audioData->mChannels; ++i) {
        ConvertAudioSamples(&bufferData[i * audioData->mFrames],
                            mDecodeJob.mChannelBuffers[i] + mDecodeJob.mWriteIndex,
                            audioData->mFrames);

        if (i == audioData->mChannels - 1) {
          mDecodeJob.mWriteIndex += audioData->mFrames;
        }
      }
    }
  }

  if (sampleRate != destSampleRate) {
    uint32_t inputLatency = speex_resampler_get_input_latency(resampler);
    const uint32_t maxOutSamples = resampledFrames - mDecodeJob.mWriteIndex;
    for (uint32_t i = 0; i < channelCount; ++i) {
      uint32_t inSamples = inputLatency;
      uint32_t outSamples = maxOutSamples;

      WebAudioUtils::SpeexResamplerProcess(
          resampler, i, (AudioDataValue*)nullptr, &inSamples,
          mDecodeJob.mChannelBuffers[i] + mDecodeJob.mWriteIndex,
          &outSamples);

      if (i == channelCount - 1) {
        mDecodeJob.mWriteIndex += outSamples;
        MOZ_ASSERT(mDecodeJob.mWriteIndex <= resampledFrames);
        MOZ_ASSERT(inSamples == inputLatency);
      }
    }
  }

  mPhase = PhaseEnum::AllocateBuffer;
  NS_DispatchToMainThread(this);
}

void
MediaDecodeTask::AllocateBuffer()
{
  MOZ_ASSERT(NS_IsMainThread());

  if (!mDecodeJob.AllocateBuffer()) {
    ReportFailureOnMainThread(WebAudioDecodeJob::UnknownError);
    return;
  }

  mPhase = PhaseEnum::Done;
  CallbackTheResult();
}

void
MediaDecodeTask::CallbackTheResult()
{
  MOZ_ASSERT(NS_IsMainThread());

  Cleanup();

  // Now, we're ready to call the script back with the resulting buffer
  mDecodeJob.OnSuccess(WebAudioDecodeJob::NoError);
}

bool
WebAudioDecodeJob::AllocateBuffer()
{
  MOZ_ASSERT(!mOutput);
  MOZ_ASSERT(NS_IsMainThread());

  AutoJSAPI jsapi;
  if (NS_WARN_IF(!jsapi.Init(mContext->GetOwner()))) {
    return false;
  }
  JSContext* cx = jsapi.cx();

  // Now create the AudioBuffer
  ErrorResult rv;
  mOutput = AudioBuffer::Create(mContext, mChannelBuffers.Length(),
                                mWriteIndex, mContext->SampleRate(), cx, rv);
  if (rv.Failed()) {
    return false;
  }

  for (uint32_t i = 0; i < mChannelBuffers.Length(); ++i) {
    mOutput->SetRawChannelContents(i, mChannelBuffers[i]);
  }

  return true;
}

void
MediaBufferDecoder::AsyncDecodeMedia(const char* aContentType, uint8_t* aBuffer,
                                     uint32_t aLength,
                                     WebAudioDecodeJob& aDecodeJob)
{
  // Do not attempt to decode the media if we were not successful at sniffing
  // the content type.
  if (!*aContentType ||
      strcmp(aContentType, APPLICATION_OCTET_STREAM) == 0) {
    nsCOMPtr<nsIRunnable> event =
      new ReportResultTask(aDecodeJob,
                           &WebAudioDecodeJob::OnFailure,
                           WebAudioDecodeJob::UnknownContent);
    JS_free(nullptr, aBuffer);
    NS_DispatchToMainThread(event);
    return;
  }

  if (!EnsureThreadPoolInitialized()) {
    nsCOMPtr<nsIRunnable> event =
      new ReportResultTask(aDecodeJob,
                           &WebAudioDecodeJob::OnFailure,
                           WebAudioDecodeJob::UnknownError);
    JS_free(nullptr, aBuffer);
    NS_DispatchToMainThread(event);
    return;
  }

  MOZ_ASSERT(mThreadPool);

  nsRefPtr<MediaDecodeTask> task =
    new MediaDecodeTask(aContentType, aBuffer, aLength, aDecodeJob, mThreadPool);
  if (!task->CreateReader()) {
    nsCOMPtr<nsIRunnable> event =
      new ReportResultTask(aDecodeJob,
                           &WebAudioDecodeJob::OnFailure,
                           WebAudioDecodeJob::UnknownError);
    NS_DispatchToMainThread(event);
  } else {
    mThreadPool->Dispatch(task, nsIThreadPool::DISPATCH_NORMAL);
  }
}

bool
MediaBufferDecoder::EnsureThreadPoolInitialized()
{
  if (!mThreadPool) {
    mThreadPool = do_CreateInstance(NS_THREADPOOL_CONTRACTID);
    if (!mThreadPool) {
      return false;
    }
    mThreadPool->SetName(NS_LITERAL_CSTRING("MediaBufferDecoder"));
#ifdef XP_WIN
  // Ensure MSCOM is initialized on the thread pools threads.
  nsCOMPtr<nsIThreadPoolListener> listener = new MSCOMInitThreadPoolListener();
  nsresult rv = mThreadPool->SetListener(listener);
  NS_ENSURE_SUCCESS(rv, nullptr);
#endif
  }
  return true;
}

void
MediaBufferDecoder::Shutdown() {
  if (mThreadPool) {
    // Setting threadLimit to 0 causes threads to exit when all events have
    // been run, like nsIThreadPool::Shutdown(), but doesn't run a nested event
    // loop nor wait until this has happened.
    mThreadPool->SetThreadLimit(0);
    mThreadPool = nullptr;
  }
}

WebAudioDecodeJob::WebAudioDecodeJob(const nsACString& aContentType,
                                     AudioContext* aContext,
                                     Promise* aPromise,
                                     DecodeSuccessCallback* aSuccessCallback,
                                     DecodeErrorCallback* aFailureCallback)
  : mContentType(aContentType)
  , mWriteIndex(0)
  , mContext(aContext)
  , mPromise(aPromise)
  , mSuccessCallback(aSuccessCallback)
  , mFailureCallback(aFailureCallback)
{
  MOZ_ASSERT(aContext);
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_COUNT_CTOR(WebAudioDecodeJob);
}

WebAudioDecodeJob::~WebAudioDecodeJob()
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_COUNT_DTOR(WebAudioDecodeJob);
}

void
WebAudioDecodeJob::OnSuccess(ErrorCode aErrorCode)
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aErrorCode == NoError);

  // Ignore errors in calling the callback, since there is not much that we can
  // do about it here.
  ErrorResult rv;
  if (mSuccessCallback) {
    mSuccessCallback->Call(*mOutput, rv);
  }
  mPromise->MaybeResolve(mOutput);

  mContext->RemoveFromDecodeQueue(this);
}

void
WebAudioDecodeJob::OnFailure(ErrorCode aErrorCode)
{
  MOZ_ASSERT(NS_IsMainThread());

  const char* errorMessage;
  switch (aErrorCode) {
  case NoError:
    MOZ_ASSERT(false, "Who passed NoError to OnFailure?");
    // Fall through to get some sort of a sane error message if this actually
    // happens at runtime.
  case UnknownError:
    errorMessage = "MediaDecodeAudioDataUnknownError";
    break;
  case UnknownContent:
    errorMessage = "MediaDecodeAudioDataUnknownContentType";
    break;
  case InvalidContent:
    errorMessage = "MediaDecodeAudioDataInvalidContent";
    break;
  case NoAudio:
    errorMessage = "MediaDecodeAudioDataNoAudio";
    break;
  }

  nsCOMPtr<nsPIDOMWindow> pWindow = do_QueryInterface(mContext->GetParentObject());
  nsIDocument* doc = nullptr;
  if (pWindow) {
    doc = pWindow->GetExtantDoc();
  }
  nsContentUtils::ReportToConsole(nsIScriptError::errorFlag,
                                  NS_LITERAL_CSTRING("Media"),
                                  doc,
                                  nsContentUtils::eDOM_PROPERTIES,
                                  errorMessage);

  // Ignore errors in calling the callback, since there is not much that we can
  // do about it here.
  if (mFailureCallback) {
    ErrorResult rv;
    mFailureCallback->Call(rv);
  }

  mPromise->MaybeReject(NS_ERROR_DOM_ENCODING_NOT_SUPPORTED_ERR);

  mContext->RemoveFromDecodeQueue(this);
}

size_t
WebAudioDecodeJob::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
  size_t amount = 0;
  amount += mContentType.SizeOfExcludingThisMustBeUnshared(aMallocSizeOf);
  if (mSuccessCallback) {
    amount += mSuccessCallback->SizeOfIncludingThis(aMallocSizeOf);
  }
  if (mFailureCallback) {
    amount += mFailureCallback->SizeOfIncludingThis(aMallocSizeOf);
  }
  if (mOutput) {
    amount += mOutput->SizeOfIncludingThis(aMallocSizeOf);
  }
  amount += mChannelBuffers.SizeOfExcludingThis(aMallocSizeOf);
  for (uint32_t i = 0; i < mChannelBuffers.Length(); ++i) {
    amount += mChannelBuffers[i].SizeOfExcludingThis(aMallocSizeOf);
  }
  return amount;
}

size_t
WebAudioDecodeJob::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}

}