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

65 строки
2.3 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 PANNING_UTILS_H
#define PANNING_UTILS_H
#include "AudioSegment.h"
#include "AudioNodeEngine.h"
namespace mozilla {
namespace dom {
template <typename T>
void GainMonoToStereo(const AudioBlock& aInput, AudioBlock* aOutput, T aGainL,
T aGainR) {
float* outputL = aOutput->ChannelFloatsForWrite(0);
float* outputR = aOutput->ChannelFloatsForWrite(1);
const float* input = static_cast<const float*>(aInput.mChannelData[0]);
MOZ_ASSERT(aInput.ChannelCount() == 1);
MOZ_ASSERT(aOutput->ChannelCount() == 2);
AudioBlockPanMonoToStereo(input, aGainL, aGainR, outputL, outputR);
}
// T can be float or an array of float, and U can be bool or an array of bool,
// depending if the value of the parameters are constant for this block.
template <typename T, typename U>
void GainStereoToStereo(const AudioBlock& aInput, AudioBlock* aOutput, T aGainL,
T aGainR, U aOnLeft) {
float* outputL = aOutput->ChannelFloatsForWrite(0);
float* outputR = aOutput->ChannelFloatsForWrite(1);
const float* inputL = static_cast<const float*>(aInput.mChannelData[0]);
const float* inputR = static_cast<const float*>(aInput.mChannelData[1]);
MOZ_ASSERT(aInput.ChannelCount() == 2);
MOZ_ASSERT(aOutput->ChannelCount() == 2);
AudioBlockPanStereoToStereo(inputL, inputR, aGainL, aGainR, aOnLeft, outputL,
outputR);
}
// T can be float or an array of float, and U can be bool or an array of bool,
// depending if the value of the parameters are constant for this block.
template <typename T, typename U>
void ApplyStereoPanning(const AudioBlock& aInput, AudioBlock* aOutput, T aGainL,
T aGainR, U aOnLeft) {
aOutput->AllocateChannels(2);
if (aInput.ChannelCount() == 1) {
GainMonoToStereo(aInput, aOutput, aGainL, aGainR);
} else {
GainStereoToStereo(aInput, aOutput, aGainL, aGainR, aOnLeft);
}
aOutput->mVolume = aInput.mVolume;
}
} // namespace dom
} // namespace mozilla
#endif // PANNING_UTILS_H