gecko-dev/content/media/webaudio/AudioBuffer.h
Nicholas Nethercote 01c70c8c97 Bug 911020 - Introduce js/TypeDecls.h, which holds very commonly used type declarations from the JS engine. r=luke.
--HG--
extra : rebase_source : 008ef689989f93b46627b8be8608bdbc544ca3a2
2013-08-27 19:59:14 -07:00

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3.2 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/. */
#ifndef AudioBuffer_h_
#define AudioBuffer_h_
#include "nsWrapperCache.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/Attributes.h"
#include "EnableWebAudioCheck.h"
#include "nsAutoPtr.h"
#include "nsTArray.h"
#include "AudioContext.h"
#include "js/TypeDecls.h"
namespace mozilla {
class ErrorResult;
class ThreadSharedFloatArrayBufferList;
namespace dom {
class AudioContext;
/**
* An AudioBuffer keeps its data either in the mJSChannels objects, which
* are Float32Arrays, or in mSharedChannels if the mJSChannels objects have
* been neutered.
*/
class AudioBuffer MOZ_FINAL : public nsWrapperCache,
public EnableWebAudioCheck
{
public:
AudioBuffer(AudioContext* aContext, uint32_t aLength,
float aSampleRate);
~AudioBuffer();
// This function needs to be called in order to allocate
// all of the channels. It is fallible!
bool InitializeBuffers(uint32_t aNumberOfChannels,
JSContext* aJSContext);
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AudioBuffer)
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AudioBuffer)
AudioContext* GetParentObject() const
{
return mContext;
}
virtual JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
float SampleRate() const
{
return mSampleRate;
}
int32_t Length() const
{
return mLength;
}
double Duration() const
{
return mLength / static_cast<double> (mSampleRate);
}
uint32_t NumberOfChannels() const
{
return mJSChannels.Length();
}
/**
* If mSharedChannels is non-null, copies its contents to
* new Float32Arrays in mJSChannels. Returns a Float32Array.
*/
JSObject* GetChannelData(JSContext* aJSContext, uint32_t aChannel,
ErrorResult& aRv);
/**
* Returns a ThreadSharedFloatArrayBufferList containing the sample data.
* Can return null if there is no data.
*/
ThreadSharedFloatArrayBufferList* GetThreadSharedChannelsForRate(JSContext* aContext);
// This replaces the contents of the JS array for the given channel.
// This function needs to be called on an AudioBuffer which has not been
// handed off to the content yet, and right after the object has been
// initialized.
void SetRawChannelContents(JSContext* aJSContext,
uint32_t aChannel,
float* aContents);
void MixToMono(JSContext* aJSContext);
protected:
bool RestoreJSChannelData(JSContext* aJSContext);
void ClearJSChannels();
nsRefPtr<AudioContext> mContext;
// Float32Arrays
AutoFallibleTArray<JS::Heap<JSObject*>, 2> mJSChannels;
// mSharedChannels aggregates the data from mJSChannels. This is non-null
// if and only if the mJSChannels are neutered.
nsRefPtr<ThreadSharedFloatArrayBufferList> mSharedChannels;
uint32_t mLength;
float mSampleRate;
};
}
}
#endif