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/*
* Copyright (C) 2010, Google 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"
#if ENABLE(WEB_AUDIO)
#include "EqualPowerPanner.h"
#include "AudioBus.h"
#include "AudioUtilities.h"
#include "VectorMath.h"
#include <algorithm>
#include <wtf/MathExtras.h>
namespace WebCore {
EqualPowerPanner::EqualPowerPanner()
: Panner(PanningModelType::Equalpower)
{
}
void EqualPowerPanner::calculateDesiredGain(double& desiredGainL, double& desiredGainR, double azimuth, unsigned numberOfChannels)
{
// Clamp azimuth to allowed range of -180 -> +180.
azimuth = std::clamp(azimuth, -180.0, 180.0);
// Alias the azimuth ranges behind us to in front of us:
// -90 -> -180 to -90 -> 0 and 90 -> 180 to 90 -> 0
if (azimuth < -90)
azimuth = -180 - azimuth;
else if (azimuth > 90)
azimuth = 180 - azimuth;
double desiredPanPosition;
if (numberOfChannels == 1) { // For mono source case.
// Pan smoothly from left to right with azimuth going from -90 -> +90
// degrees.
desiredPanPosition = (azimuth + 90) / 180;
} else { // For stereo source case.
if (azimuth <= 0) { // from -90 -> 0
// sourceL -> destL and "equal-power pan" sourceR as in mono case
// by transforming the "azimuth" value from -90 -> 0 degrees into the
// range -90 -> +90.
desiredPanPosition = (azimuth + 90) / 90;
} else { // from 0 -> +90
// sourceR -> destR and "equal-power pan" sourceL as in mono case
// by transforming the "azimuth" value from 0 -> +90 degrees into the
// range -90 -> +90.
desiredPanPosition = azimuth / 90;
}
}
desiredGainL = std::cos(piOverTwoDouble * desiredPanPosition);
desiredGainR = std::sin(piOverTwoDouble * desiredPanPosition);
}
void EqualPowerPanner::pan(double azimuth, double /*elevation*/, const AudioBus* inputBus, AudioBus* outputBus, 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;
const float* sourceL = inputBus->channel(0)->data();
const float* sourceR = numberOfInputChannels > 1 ? inputBus->channel(1)->data() : sourceL;
float* destinationL = outputBus->channelByType(AudioBus::ChannelLeft)->mutableData();
float* destinationR = outputBus->channelByType(AudioBus::ChannelRight)->mutableData();
if (!sourceL || !sourceR || !destinationL || !destinationR)
return;
// Clamp azimuth to allowed range of -180 -> +180.
azimuth = std::max(-180.0, azimuth);
azimuth = std::min(180.0, azimuth);
// Alias the azimuth ranges behind us to in front of us:
// -90 -> -180 to -90 -> 0 and 90 -> 180 to 90 -> 0
if (azimuth < -90)
azimuth = -180 - azimuth;
else if (azimuth > 90)
azimuth = 180 - azimuth;
double desiredPanPosition;
if (numberOfInputChannels == 1) { // For mono source case.
// Pan smoothly from left to right with azimuth going from -90 -> +90 degrees.
desiredPanPosition = (azimuth + 90) / 180;
} else { // For stereo source case.
if (azimuth <= 0) { // from -90 -> 0
// sourceL -> destL and "equal-power pan" sourceR as in mono case
// by transforming the "azimuth" value from -90 -> 0 degrees into the range -90 -> +90.
desiredPanPosition = (azimuth + 90) / 90;
} else { // from 0 -> +90
// sourceR -> destR and "equal-power pan" sourceL as in mono case
// by transforming the "azimuth" value from 0 -> +90 degrees into the range -90 -> +90.
desiredPanPosition = azimuth / 90;
}
}
double desiredGainL = std::cos(piOverTwoDouble * desiredPanPosition);
double desiredGainR = std::sin(piOverTwoDouble * desiredPanPosition);
if (numberOfInputChannels == 1) { // For mono source case.
VectorMath::multiplyByScalar(sourceL, desiredGainL, destinationL, framesToProcess);
VectorMath::multiplyByScalar(sourceL, desiredGainR, destinationR, framesToProcess);
} else { // For stereo source case.
if (azimuth <= 0) { // from -90 -> 0
VectorMath::multiplyByScalarThenAddToVector(sourceR, desiredGainL, sourceL, destinationL, framesToProcess);
VectorMath::multiplyByScalar(sourceR, desiredGainR, destinationR, framesToProcess);
} else { // from 0 -> +90
VectorMath::multiplyByScalar(sourceL, desiredGainL, destinationL, framesToProcess);
VectorMath::multiplyByScalarThenAddToVector(sourceL, desiredGainR, sourceR, destinationR, framesToProcess);
}
}
}
void EqualPowerPanner::panWithSampleAccurateValues(double* azimuth, double*, const AudioBus* inputBus, AudioBus* outputBus, size_t framesToProcess)
{
ASSERT(inputBus);
ASSERT(framesToProcess <= inputBus->length());
ASSERT(inputBus->numberOfChannels() >= 1u);
ASSERT(inputBus->numberOfChannels() <= 2u);
unsigned numberOfInputChannels = inputBus->numberOfChannels();
ASSERT(outputBus);
ASSERT(outputBus->numberOfChannels() == 2u);
ASSERT(framesToProcess <= outputBus->length());
const float* sourceL = inputBus->channel(0)->data();
const float* sourceR = numberOfInputChannels > 1 ? inputBus->channel(1)->data() : sourceL;
float* destinationL = outputBus->channelByType(AudioBus::ChannelLeft)->mutableData();
float* destinationR = outputBus->channelByType(AudioBus::ChannelRight)->mutableData();
ASSERT(sourceL);
ASSERT(sourceR);
ASSERT(destinationL);
ASSERT(destinationR);
int n = framesToProcess;
if (numberOfInputChannels == 1) { // For mono source case.
for (int k = 0; k < n; ++k) {
double desiredGainL;
double desiredGainR;
float inputL = *sourceL++;
calculateDesiredGain(desiredGainL, desiredGainR, azimuth[k], numberOfInputChannels);
*destinationL++ = static_cast<float>(inputL * desiredGainL);
*destinationR++ = static_cast<float>(inputL * desiredGainR);
}
} else { // For stereo source case.
for (int k = 0; k < n; ++k) {
double desiredGainL;
double desiredGainR;
calculateDesiredGain(desiredGainL, desiredGainR, azimuth[k], numberOfInputChannels);
if (azimuth[k] <= 0) { // from -90 -> 0
float inputL = *sourceL++;
float inputR = *sourceR++;
*destinationL++ = static_cast<float>(inputL + inputR * desiredGainL);
*destinationR++ = static_cast<float>(inputR * desiredGainR);
} else { // from 0 -> +90
float inputL = *sourceL++;
float inputR = *sourceR++;
*destinationL++ = static_cast<float>(inputL * desiredGainL);
*destinationR++ = static_cast<float>(inputR + inputL * desiredGainR);
}
}
}
}
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO)
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