gecko-dev/content/media/webaudio/DelayProcessor.h

61 строка
1.9 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 DelayProcessor_h_
#define DelayProcessor_h_
#include "nsTArray.h"
namespace mozilla {
class DelayProcessor {
public:
// See WebAudioUtils::ComputeSmoothingRate() for frame to frame exponential
// |smoothingRate| multiplier.
DelayProcessor(int aMaxDelayFrames, double aSmoothingRate)
: mSmoothingRate(aSmoothingRate)
, mCurrentDelay(0.)
, mMaxDelayFrames(aMaxDelayFrames)
, mWriteIndex(0)
{
}
// Process with an array of delays, in frames, for each frame.
void Process(const double *aPerFrameDelays,
const float* const* aInputChannels,
float* const* aOutputChannels,
int aChannelCount, int aFramesToProcess);
// Process with a constant delay, which will be smoothed with the previous
// delay.
void Process(double aDelayFrames, const float* const* aInputChannels,
float* const* aOutputChannels, int aChannelCount,
int aFramesToProcess);
void Reset() { mBuffer.Clear(); };
int MaxDelayFrames() const { return mMaxDelayFrames; }
int BufferChannelCount() const { return mBuffer.Length(); }
private:
bool EnsureBuffer(uint32_t aNumberOfChannels);
// Circular buffer for capturing delayed samples.
AutoFallibleTArray<FallibleTArray<float>, 2> mBuffer;
double mSmoothingRate;
// Current delay, in fractional frames
double mCurrentDelay;
// Maximum delay, in frames
int mMaxDelayFrames;
// Write index for the buffer, to write the frames to the correct index of the buffer
// given the current delay.
int mWriteIndex;
};
} // mozilla
#endif // DelayProcessor_h_