| /* |
| * 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 "platform/audio/EqualPowerPanner.h" |
| #include "platform/audio/AudioBus.h" |
| #include "platform/audio/AudioUtilities.h" |
| #include "wtf/MathExtras.h" |
| #include <algorithm> |
| #include <cmath> |
| |
| namespace blink { |
| |
| EqualPowerPanner::EqualPowerPanner(float sampleRate) |
| : Panner(PanningModelEqualPower) |
| { |
| } |
| |
| 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 = clampTo(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; |
| double desiredGainL; |
| double desiredGainR; |
| |
| 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; |
| } |
| } |
| |
| desiredGainL = std::cos(piOverTwoDouble * desiredPanPosition); |
| desiredGainR = std::sin(piOverTwoDouble * desiredPanPosition); |
| |
| int n = framesToProcess; |
| |
| if (numberOfInputChannels == 1) { // For mono source case. |
| while (n--) { |
| float inputL = *sourceL++; |
| |
| *destinationL++ = static_cast<float>(inputL * desiredGainL); |
| *destinationR++ = static_cast<float>(inputL * desiredGainR); |
| } |
| } else { // For stereo source case. |
| if (azimuth <= 0) { // from -90 -> 0 |
| while (n--) { |
| float inputL = *sourceL++; |
| float inputR = *sourceR++; |
| |
| *destinationL++ = static_cast<float>(inputL + inputR * desiredGainL); |
| *destinationR++ = static_cast<float>(inputR * desiredGainR); |
| } |
| } else { // from 0 -> +90 |
| while (n--) { |
| float inputL = *sourceL++; |
| float inputR = *sourceR++; |
| |
| *destinationL++ = static_cast<float>(inputL * desiredGainL); |
| *destinationR++ = static_cast<float>(inputR + inputL * desiredGainR); |
| } |
| } |
| } |
| } |
| |
| void EqualPowerPanner::calculateDesiredGain(double& desiredGainL, double& desiredGainR, double azimuth, int numberOfInputChannels) |
| { |
| // Clamp azimuth to allowed range of -180 -> +180. |
| azimuth = clampTo(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 (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; |
| } |
| } |
| |
| desiredGainL = std::cos(piOverTwoDouble * desiredPanPosition); |
| desiredGainR = std::sin(piOverTwoDouble * desiredPanPosition); |
| } |
| |
| void EqualPowerPanner::panWithSampleAccurateValues(double* azimuth, double* /*elevation*/, const AudioBus* inputBus, AudioBus* outputBus, size_t framesToProcess) |
| { |
| bool isInputSafe = inputBus && (inputBus->numberOfChannels() == 1 || inputBus->numberOfChannels() == 2) && framesToProcess <= inputBus->length(); |
| DCHECK(isInputSafe); |
| if (!isInputSafe) |
| return; |
| |
| unsigned numberOfInputChannels = inputBus->numberOfChannels(); |
| |
| bool isOutputSafe = outputBus && outputBus->numberOfChannels() == 2 && framesToProcess <= outputBus->length(); |
| DCHECK(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; |
| |
| 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 blink |
| |
