gecko-dev/dom/media/webaudio/AudioBuffer.h

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3.9 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 "nsAutoPtr.h"
#include "nsTArray.h"
#include "AudioContext.h"
#include "js/TypeDecls.h"
#include "mozilla/MemoryReporting.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 final : public nsWrapperCache
{
public:
// If non-null, aInitialContents must have number of channels equal to
// aNumberOfChannels and their lengths must be at least aLength.
static already_AddRefed<AudioBuffer>
Create(AudioContext* aContext, uint32_t aNumberOfChannels,
uint32_t aLength, float aSampleRate,
already_AddRefed<ThreadSharedFloatArrayBufferList> aInitialContents,
JSContext* aJSContext, ErrorResult& aRv);
static already_AddRefed<AudioBuffer>
Create(AudioContext* aContext, uint32_t aNumberOfChannels,
uint32_t aLength, float aSampleRate,
JSContext* aJSContext, ErrorResult& aRv)
{
return Create(aContext, aNumberOfChannels, aLength, aSampleRate,
nullptr, aJSContext, aRv);
}
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AudioBuffer)
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AudioBuffer)
nsPIDOMWindow* GetParentObject() const
{
nsCOMPtr<nsPIDOMWindow> parentObject = do_QueryReferent(mOwnerWindow);
return parentObject;
}
virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) 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.
*/
void GetChannelData(JSContext* aJSContext, uint32_t aChannel,
JS::MutableHandle<JSObject*> aRetval,
ErrorResult& aRv);
void CopyFromChannel(const Float32Array& aDestination, uint32_t aChannelNumber,
uint32_t aStartInChannel, ErrorResult& aRv);
void CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,
uint32_t aChannelNumber, uint32_t aStartInChannel,
ErrorResult& aRv);
/**
* Returns a ThreadSharedFloatArrayBufferList containing the sample data.
* Can return null if there is no data.
*/
ThreadSharedFloatArrayBufferList* GetThreadSharedChannelsForRate(JSContext* aContext);
protected:
AudioBuffer(AudioContext* aContext, uint32_t aNumberOfChannels,
uint32_t aLength, float aSampleRate,
already_AddRefed<ThreadSharedFloatArrayBufferList>
aInitialContents);
~AudioBuffer();
bool RestoreJSChannelData(JSContext* aJSContext);
void ClearJSChannels();
nsWeakPtr mOwnerWindow;
// Float32Arrays
nsAutoTArray<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;
};
} // namespace dom
} // namespace mozilla
#endif