gecko/content/media/webaudio/AnalyserNode.h
Ehsan Akhgari 8353ddad3c Bug 815643 - Part 2: Refactor our Web Audio FFT code into the FFTBlock class; r=roc
This is useful in order for us to be able to borrow code from Blink with
fewer changes, and also to explore faster platform dependent FFT
implementations in the future if needed.

--HG--
extra : rebase_source : 34bbded736e1b385754756513c59ee27ce7552a5
2013-06-10 16:08:21 -04:00

78 lines
1.8 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/. */
#ifndef AnalyserNode_h_
#define AnalyserNode_h_
#include "AudioNode.h"
#include "FFTBlock.h"
namespace mozilla {
namespace dom {
class AudioContext;
class AnalyserNode : public AudioNode
{
public:
explicit AnalyserNode(AudioContext* aContext);
NS_DECL_ISUPPORTS_INHERITED
virtual JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
void GetFloatFrequencyData(Float32Array& aArray);
void GetByteFrequencyData(Uint8Array& aArray);
void GetByteTimeDomainData(Uint8Array& aArray);
uint32_t FftSize() const
{
return mAnalysisBlock.FFTSize();
}
void SetFftSize(uint32_t aValue, ErrorResult& aRv);
uint32_t FrequencyBinCount() const
{
return FftSize() / 2;
}
double MinDecibels() const
{
return mMinDecibels;
}
void SetMinDecibels(double aValue, ErrorResult& aRv);
double MaxDecibels() const
{
return mMaxDecibels;
}
void SetMaxDecibels(double aValue, ErrorResult& aRv);
double SmoothingTimeConstant() const
{
return mSmoothingTimeConstant;
}
void SetSmoothingTimeConstant(double aValue, ErrorResult& aRv);
private:
friend class AnalyserNodeEngine;
void AppendChunk(const AudioChunk& aChunk);
bool AllocateBuffer();
bool FFTAnalysis();
void ApplyBlackmanWindow(float* aBuffer, uint32_t aSize);
private:
FFTBlock mAnalysisBlock;
double mMinDecibels;
double mMaxDecibels;
double mSmoothingTimeConstant;
uint32_t mWriteIndex;
FallibleTArray<float> mBuffer;
FallibleTArray<float> mOutputBuffer;
};
}
}
#endif