gecko/content/media/AudioNodeEngine.cpp

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/* -*- 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 "AudioNodeEngine.h"
namespace mozilla {
void
AllocateAudioBlock(uint32_t aChannelCount, AudioChunk* aChunk)
{
// XXX for SIMD purposes we should do something here to make sure the
// channel buffers are 16-byte aligned.
nsRefPtr<SharedBuffer> buffer =
SharedBuffer::Create(WEBAUDIO_BLOCK_SIZE*aChannelCount*sizeof(float));
aChunk->mDuration = WEBAUDIO_BLOCK_SIZE;
aChunk->mChannelData.SetLength(aChannelCount);
float* data = static_cast<float*>(buffer->Data());
for (uint32_t i = 0; i < aChannelCount; ++i) {
aChunk->mChannelData[i] = data + i*WEBAUDIO_BLOCK_SIZE;
}
aChunk->mBuffer = buffer.forget();
aChunk->mVolume = 1.0f;
aChunk->mBufferFormat = AUDIO_FORMAT_FLOAT32;
}
void
WriteZeroesToAudioBlock(AudioChunk* aChunk, uint32_t aStart, uint32_t aLength)
{
MOZ_ASSERT(aStart + aLength <= WEBAUDIO_BLOCK_SIZE);
if (aLength == 0)
return;
for (uint32_t i = 0; i < aChunk->mChannelData.Length(); ++i) {
memset(static_cast<float*>(const_cast<void*>(aChunk->mChannelData[i])) + aStart,
0, aLength*sizeof(float));
}
}
void
AudioBlockAddChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
float aScale,
float aOutput[WEBAUDIO_BLOCK_SIZE])
{
if (aScale == 1.0f) {
for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
aOutput[i] += aInput[i];
}
} else {
for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
aOutput[i] += aInput[i]*aScale;
}
}
}
void
AudioBlockCopyChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
float aScale,
float aOutput[WEBAUDIO_BLOCK_SIZE])
{
if (aScale == 1.0f) {
memcpy(aOutput, aInput, WEBAUDIO_BLOCK_SIZE*sizeof(float));
} else {
for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
aOutput[i] = aInput[i]*aScale;
}
}
}
}