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

66 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 AudioChunk& aInput, AudioChunk* aOutput,
T aGainL, T aGainR)
{
float* outputL = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
float* outputR = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[1]));
const float* input = static_cast<float*>(const_cast<void*>(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 AudioChunk& aInput, AudioChunk* aOutput,
T aGainL, T aGainR, U aOnLeft)
{
float* outputL = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
float* outputR = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[1]));
const float* inputL = static_cast<float*>(const_cast<void*>(aInput.mChannelData[0]));
const float* inputR = static_cast<float*>(const_cast<void*>(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 AudioChunk& aInput, AudioChunk* aOutput,
T aGainL, T aGainR, U aOnLeft)
{
if (aInput.mChannelData.Length() == 1) {
GainMonoToStereo(aInput, aOutput, aGainL, aGainR);
} else {
GainStereoToStereo(aInput, aOutput, aGainL, aGainR, aOnLeft);
}
}
} // dom
} // mozilla
#endif // PANNING_UTILS_H