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/*
* Copyright 2014 The Chromium Authors. All rights reserved.
* Copyright (C) 2020 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "StereoPanner.h"
#if ENABLE(WEB_AUDIO)
#include "SharedBuffer.h"
#include "VectorMath.h"
#include <wtf/IndexedRange.h>
#include <wtf/MathExtras.h>
namespace WebCore {
namespace StereoPanner {
void panWithSampleAccurateValues(const AudioBus* inputBus, AudioBus* outputBus, std::span<const float> panValues)
{
bool isInputSafe = inputBus && (inputBus->numberOfChannels() == 1 || inputBus->numberOfChannels() == 2) && panValues.size() <= inputBus->length();
ASSERT(isInputSafe);
if (!isInputSafe)
return;
unsigned numberOfInputChannels = inputBus->numberOfChannels();
bool isOutputSafe = outputBus && outputBus->numberOfChannels() == 2 && panValues.size() <= outputBus->length();
ASSERT(isOutputSafe);
if (!isOutputSafe)
return;
auto sourceL = inputBus->channel(0)->span();
auto sourceR = numberOfInputChannels > 1 ? inputBus->channel(1)->span() : sourceL;
auto destinationL = outputBus->channelByType(AudioBus::ChannelLeft)->mutableSpan();
auto destinationR = outputBus->channelByType(AudioBus::ChannelRight)->mutableSpan();
double gainL;
double gainR;
double panRadian;
// Handles mono source case first, then stereo source case.
if (numberOfInputChannels == 1) {
for (auto [i, panValue] : indexedRange(panValues)) {
float inputL = sourceL[i];
double pan = clampTo(panValue, -1.0, 1.0);
// Pan from left to right [-1; 1] will be normalized as [0; 1].
panRadian = (pan * 0.5 + 0.5) * piOverTwoDouble;
gainL = cos(panRadian);
gainR = sin(panRadian);
destinationL[i] = static_cast<float>(inputL * gainL);
destinationR[i] = static_cast<float>(inputL * gainR);
}
} else {
for (auto [i, panValue] : indexedRange(panValues)) {
float inputL = sourceL[i];
float inputR = sourceR[i];
double pan = clampTo(panValue, -1.0, 1.0);
// Normalize [-1; 0] to [0; 1]. Do nothing when [0; 1].
panRadian = (pan <= 0 ? pan + 1 : pan) * piOverTwoDouble;
gainL = cos(panRadian);
gainR = sin(panRadian);
if (pan <= 0) {
destinationL[i] = static_cast<float>(inputL + inputR * gainL);
destinationR[i] = static_cast<float>(inputR * gainR);
} else {
destinationL[i] = static_cast<float>(inputL * gainL);
destinationR[i] = static_cast<float>(inputR + inputL * gainR);
}
}
}
}
void panToTargetValue(const AudioBus* inputBus, AudioBus* outputBus, float panValue, size_t framesToProcess)
{
bool isInputSafe = inputBus && (inputBus->numberOfChannels() == 1 || inputBus->numberOfChannels() == 2) && framesToProcess <= inputBus->length();
ASSERT(isInputSafe);
if (!isInputSafe)
return;
unsigned numberOfInputChannels = inputBus->numberOfChannels();
bool isOutputSafe = outputBus && outputBus->numberOfChannels() == 2 && framesToProcess <= outputBus->length();
ASSERT(isOutputSafe);
if (!isOutputSafe)
return;
auto sourceL = inputBus->channel(0)->span().first(framesToProcess);
auto sourceR = numberOfInputChannels > 1 ? inputBus->channel(1)->span().first(framesToProcess) : sourceL;
auto destinationL = outputBus->channelByType(AudioBus::ChannelLeft)->mutableSpan();
auto destinationR = outputBus->channelByType(AudioBus::ChannelRight)->mutableSpan();
float targetPan = clampTo(panValue, -1.0, 1.0);
if (numberOfInputChannels == 1) {
double panRadian = (targetPan * 0.5 + 0.5) * piOverTwoDouble;
double gainL = cos(panRadian);
double gainR = sin(panRadian);
VectorMath::multiplyByScalar(sourceL, gainL, destinationL);
VectorMath::multiplyByScalar(sourceL, gainR, destinationR);
} else {
double panRadian = (targetPan <= 0 ? targetPan + 1 : targetPan) * piOverTwoDouble;
double gainL = cos(panRadian);
double gainR = sin(panRadian);
if (targetPan <= 0) {
VectorMath::multiplyByScalarThenAddToVector(sourceR, gainL, sourceL, destinationL);
VectorMath::multiplyByScalar(sourceR, gainR, destinationR);
} else {
VectorMath::multiplyByScalar(sourceL, gainL, destinationL);
VectorMath::multiplyByScalarThenAddToVector(sourceL, gainR, sourceR, destinationR);
}
}
}
} // namespace StereoPanner
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO)
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