/* static */ already_AddRefed<AudioBuffer> AudioBuffer::Create(nsPIDOMWindowInner* aWindow, float aSampleRate, AudioChunk&& aInitialContents) { AudioChunk initialContents = aInitialContents; ErrorResult rv; RefPtr<AudioBuffer> buffer = new AudioBuffer(aWindow, initialContents.ChannelCount(), initialContents.mDuration, aSampleRate, rv); if (rv.Failed()) { return nullptr; } buffer->mSharedChannels = Move(aInitialContents); return buffer.forget(); }
/** * Copies the data in aInput to aOffsetInBlock within aBlock. * aBlock must have been allocated with AllocateInputBlock and have a channel * count that's a superset of the channels in aInput. */ static void CopyChunkToBlock(const AudioChunk& aInput, AudioChunk *aBlock, uint32_t aOffsetInBlock) { uint32_t blockChannels = aBlock->ChannelCount(); nsAutoTArray<const void*,2> channels; if (aInput.IsNull()) { channels.SetLength(blockChannels); PodZero(channels.Elements(), blockChannels); } else { channels.SetLength(aInput.ChannelCount()); PodCopy(channels.Elements(), aInput.mChannelData.Elements(), channels.Length()); if (channels.Length() != blockChannels) { // We only need to upmix here because aBlock's channel count has been // chosen to be a superset of the channel count of every chunk. AudioChannelsUpMix(&channels, blockChannels, nullptr); } } uint32_t duration = aInput.GetDuration(); for (uint32_t c = 0; c < blockChannels; ++c) { float* outputData = static_cast<float*>(const_cast<void*>(aBlock->mChannelData[c])) + aOffsetInBlock; if (channels[c]) { switch (aInput.mBufferFormat) { case AUDIO_FORMAT_FLOAT32: ConvertAudioSamplesWithScale( static_cast<const float*>(channels[c]), outputData, duration, aInput.mVolume); break; case AUDIO_FORMAT_S16: ConvertAudioSamplesWithScale( static_cast<const int16_t*>(channels[c]), outputData, duration, aInput.mVolume); break; default: NS_ERROR("Unhandled format"); } } else { PodZero(outputData, duration); } } }