C++ (Cpp) pcmSamples Examples

Example #1

File: WMFReader.cpp Project: LordJZ/gecko-dev

bool
WMFReader::DecodeAudioData()
{
  MOZ_ASSERT(OnTaskQueue());

  HRESULT hr;
  hr = mSourceReader->ReadSample(MF_SOURCE_READER_FIRST_AUDIO_STREAM,
                                 0, // control flags
                                 0, // read stream index
                                 nullptr,
                                 nullptr,
                                 nullptr);

  if (FAILED(hr)) {
    DECODER_LOG("WMFReader::DecodeAudioData() ReadSample failed with hr=0x%x", hr);
    // End the stream.
    return false;
  }

  DWORD flags = 0;
  LONGLONG timestampHns = 0;
  RefPtr<IMFSample> sample;
  hr = mSourceReaderCallback->Wait(&flags, &timestampHns, byRef(sample));
  if (FAILED(hr) ||
      (flags & MF_SOURCE_READERF_ERROR) ||
      (flags & MF_SOURCE_READERF_ENDOFSTREAM) ||
      (flags & MF_SOURCE_READERF_CURRENTMEDIATYPECHANGED)) {
    DECODER_LOG("WMFReader::DecodeAudioData() ReadSample failed with hr=0x%x flags=0x%x",
                hr, flags);
    // End the stream.
    return false;
  }

  if (!sample) {
    // Not enough data? Try again...
    return true;
  }

  RefPtr<IMFMediaBuffer> buffer;
  hr = sample->ConvertToContiguousBuffer(byRef(buffer));
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  BYTE* data = nullptr; // Note: *data will be owned by the IMFMediaBuffer, we don't need to free it.
  DWORD maxLength = 0, currentLength = 0;
  hr = buffer->Lock(&data, &maxLength, &currentLength);
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  uint32_t numFrames = currentLength / mAudioBytesPerSample / mAudioChannels;
  NS_ASSERTION(sizeof(AudioDataValue) == mAudioBytesPerSample, "Size calculation is wrong");
  nsAutoArrayPtr<AudioDataValue> pcmSamples(new AudioDataValue[numFrames * mAudioChannels]);
  memcpy(pcmSamples.get(), data, currentLength);
  buffer->Unlock();

  // We calculate the timestamp and the duration based on the number of audio
  // frames we've already played. We don't trust the timestamp stored on the
  // IMFSample, as sometimes it's wrong, possibly due to buggy encoders?

  // If this sample block comes after a discontinuity (i.e. a gap or seek)
  // reset the frame counters, and capture the timestamp. Future timestamps
  // will be offset from this block's timestamp.
  UINT32 discontinuity = false;
  sample->GetUINT32(MFSampleExtension_Discontinuity, &discontinuity);
  if (mMustRecaptureAudioPosition || discontinuity) {
    mAudioFrameSum = 0;
    hr = HNsToFrames(timestampHns, mAudioRate, &mAudioFrameOffset);
    NS_ENSURE_TRUE(SUCCEEDED(hr), false);
    mMustRecaptureAudioPosition = false;
  }

  int64_t timestamp;
  hr = FramesToUsecs(mAudioFrameOffset + mAudioFrameSum, mAudioRate, &timestamp);
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  mAudioFrameSum += numFrames;

  int64_t duration;
  hr = FramesToUsecs(numFrames, mAudioRate, &duration);
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  mAudioQueue.Push(new AudioData(mDecoder->GetResource()->Tell(),
                                 timestamp,
                                 duration,
                                 numFrames,
                                 pcmSamples.forget(),
                                 mAudioChannels,
                                 mAudioRate));

  #ifdef LOG_SAMPLE_DECODE
  DECODER_LOG("Decoded audio sample! timestamp=%lld duration=%lld currentLength=%u",
              timestamp, duration, currentLength);
  #endif

  return true;
}

Example #2

File: WMFReader.cpp Project: vlajos/mozilla-central

bool
WMFReader::DecodeAudioData()
{
  NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");

  HRESULT hr;
  hr = mSourceReader->ReadSample(MF_SOURCE_READER_FIRST_AUDIO_STREAM,
                                 0, // control flags
                                 0, // read stream index
                                 nullptr,
                                 nullptr,
                                 nullptr);

  if (FAILED(hr)) {
    LOG("WMFReader::DecodeAudioData() ReadSample failed with hr=0x%x", hr);
    // End the stream.
    mAudioQueue.Finish();
    return false;
  }

  DWORD flags = 0;
  LONGLONG timestampHns = 0;
  RefPtr<IMFSample> sample;
  hr = mSourceReaderCallback->Wait(&flags, &timestampHns, byRef(sample));
  if (FAILED(hr) ||
      (flags & MF_SOURCE_READERF_ERROR) ||
      (flags & MF_SOURCE_READERF_ENDOFSTREAM) ||
      (flags & MF_SOURCE_READERF_CURRENTMEDIATYPECHANGED)) {
    LOG("WMFReader::DecodeAudioData() ReadSample failed with hr=0x%x flags=0x%x",
        hr, flags);
    // End the stream.
    mAudioQueue.Finish();
    return false;
  }

  if (!sample) {
    // Not enough data? Try again...
    return true;
  }

  RefPtr<IMFMediaBuffer> buffer;
  hr = sample->ConvertToContiguousBuffer(byRef(buffer));
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  BYTE* data = nullptr; // Note: *data will be owned by the IMFMediaBuffer, we don't need to free it.
  DWORD maxLength = 0, currentLength = 0;
  hr = buffer->Lock(&data, &maxLength, &currentLength);
  NS_ENSURE_TRUE(SUCCEEDED(hr), false);

  uint32_t numFrames = currentLength / mAudioBytesPerSample / mAudioChannels;
  NS_ASSERTION(sizeof(AudioDataValue) == mAudioBytesPerSample, "Size calculation is wrong");
  nsAutoArrayPtr<AudioDataValue> pcmSamples(new AudioDataValue[numFrames * mAudioChannels]);
  memcpy(pcmSamples.get(), data, currentLength);
  buffer->Unlock();

  int64_t offset = mDecoder->GetResource()->Tell();
  int64_t timestamp = HNsToUsecs(timestampHns);
  int64_t duration = GetSampleDuration(sample);

  mAudioQueue.Push(new AudioData(offset,
                                 timestamp,
                                 duration,
                                 numFrames,
                                 pcmSamples.forget(),
                                 mAudioChannels));

  #ifdef LOG_SAMPLE_DECODE
  LOG("Decoded audio sample! timestamp=%lld duration=%lld currentLength=%u",
      timestamp, duration, currentLength);
  #endif

  return true;
}