gecko-dev/content/media/webaudio/AudioBuffer.cpp

205 lines
5.8 KiB
C++

/* -*- 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 "AudioBuffer.h"
#include "mozilla/dom/AudioBufferBinding.h"
#include "nsContentUtils.h"
#include "jsfriendapi.h"
#include "mozilla/ErrorResult.h"
#include "AudioSegment.h"
#include "AudioChannelFormat.h"
#include "mozilla/PodOperations.h"
#include "AudioNodeEngine.h"
namespace mozilla {
namespace dom {
NS_IMPL_CYCLE_COLLECTION_CLASS(AudioBuffer)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AudioBuffer)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mContext)
NS_IMPL_CYCLE_COLLECTION_UNLINK(mJSChannels)
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
tmp->ClearJSChannels();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AudioBuffer)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mContext)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(AudioBuffer)
NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
for (uint32_t i = 0; i < tmp->mJSChannels.Length(); ++i) {
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mJSChannels[i])
}
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(AudioBuffer, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(AudioBuffer, Release)
AudioBuffer::AudioBuffer(AudioContext* aContext, uint32_t aLength,
float aSampleRate)
: mContext(aContext),
mLength(aLength),
mSampleRate(aSampleRate)
{
SetIsDOMBinding();
nsContentUtils::HoldJSObjects(this, NS_CYCLE_COLLECTION_PARTICIPANT(AudioBuffer));
}
AudioBuffer::~AudioBuffer()
{
ClearJSChannels();
}
void
AudioBuffer::ClearJSChannels()
{
mJSChannels.Clear();
nsContentUtils::DropJSObjects(this);
}
bool
AudioBuffer::InitializeBuffers(uint32_t aNumberOfChannels, JSContext* aJSContext)
{
if (!mJSChannels.SetCapacity(aNumberOfChannels)) {
return false;
}
for (uint32_t i = 0; i < aNumberOfChannels; ++i) {
JS::RootedObject array(aJSContext, JS_NewFloat32Array(aJSContext, mLength));
if (!array) {
return false;
}
mJSChannels.AppendElement(array.get());
}
return true;
}
JSObject*
AudioBuffer::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
{
return AudioBufferBinding::Wrap(aCx, aScope, this);
}
bool
AudioBuffer::RestoreJSChannelData(JSContext* aJSContext)
{
if (mSharedChannels) {
for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
const float* data = mSharedChannels->GetData(i);
// The following code first zeroes the array and then copies our data
// into it. We could avoid this with additional JS APIs to construct
// an array (or ArrayBuffer) containing initial data.
JS::RootedObject array(aJSContext, JS_NewFloat32Array(aJSContext, mLength));
if (!array) {
return false;
}
memcpy(JS_GetFloat32ArrayData(array), data, sizeof(float)*mLength);
mJSChannels[i] = array;
}
mSharedChannels = nullptr;
}
return true;
}
void
AudioBuffer::SetRawChannelContents(JSContext* aJSContext, uint32_t aChannel,
float* aContents)
{
PodCopy(JS_GetFloat32ArrayData(mJSChannels[aChannel]), aContents, mLength);
}
JSObject*
AudioBuffer::GetChannelData(JSContext* aJSContext, uint32_t aChannel,
ErrorResult& aRv)
{
if (aChannel >= NumberOfChannels()) {
aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
return nullptr;
}
if (!RestoreJSChannelData(aJSContext)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
return mJSChannels[aChannel];
}
static already_AddRefed<ThreadSharedFloatArrayBufferList>
StealJSArrayDataIntoThreadSharedFloatArrayBufferList(JSContext* aJSContext,
const nsTArray<JSObject*>& aJSArrays)
{
nsRefPtr<ThreadSharedFloatArrayBufferList> result =
new ThreadSharedFloatArrayBufferList(aJSArrays.Length());
for (uint32_t i = 0; i < aJSArrays.Length(); ++i) {
JS::RootedObject arrayBuffer(aJSContext, JS_GetArrayBufferViewBuffer(aJSArrays[i]));
void* dataToFree = nullptr;
uint8_t* stolenData = nullptr;
if (arrayBuffer &&
JS_StealArrayBufferContents(aJSContext, arrayBuffer, &dataToFree,
&stolenData)) {
result->SetData(i, dataToFree, reinterpret_cast<float*>(stolenData));
} else {
return nullptr;
}
}
return result.forget();
}
ThreadSharedFloatArrayBufferList*
AudioBuffer::GetThreadSharedChannelsForRate(JSContext* aJSContext)
{
if (!mSharedChannels) {
for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
if (mLength != JS_GetTypedArrayLength(mJSChannels[i])) {
// Probably one of the arrays was neutered
return nullptr;
}
}
mSharedChannels =
StealJSArrayDataIntoThreadSharedFloatArrayBufferList(aJSContext, mJSChannels);
}
return mSharedChannels;
}
void
AudioBuffer::MixToMono(JSContext* aJSContext)
{
if (mJSChannels.Length() == 1) {
// The buffer is already mono
return;
}
// Prepare the input channels
nsAutoTArray<const void*, GUESS_AUDIO_CHANNELS> channels;
channels.SetLength(mJSChannels.Length());
for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
channels[i] = JS_GetFloat32ArrayData(mJSChannels[i]);
}
// Prepare the output channels
float* downmixBuffer = new float[mLength];
// Perform the down-mix
AudioChannelsDownMix(channels, &downmixBuffer, 1, mLength);
// Truncate the shared channels and copy the downmixed data over
mJSChannels.SetLength(1);
SetRawChannelContents(aJSContext, 0, downmixBuffer);
delete[] downmixBuffer;
}
}
}