| /* |
| * 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 "third_party/blink/renderer/platform/audio/equal_power_panner.h" |
| |
| #include <algorithm> |
| #include <cmath> |
| #include "third_party/blink/renderer/platform/audio/audio_bus.h" |
| #include "third_party/blink/renderer/platform/audio/audio_utilities.h" |
| #include "third_party/blink/renderer/platform/wtf/math_extras.h" |
| |
| namespace blink { |
| |
| EqualPowerPanner::EqualPowerPanner(float sample_rate) |
| : Panner(kPanningModelEqualPower) {} |
| |
| void EqualPowerPanner::Pan(double azimuth, |
| double /*elevation*/, |
| const AudioBus* input_bus, |
| AudioBus* output_bus, |
| size_t frames_to_process, |
| AudioBus::ChannelInterpretation) { |
| bool is_input_safe = input_bus && |
| (input_bus->NumberOfChannels() == 1 || |
| input_bus->NumberOfChannels() == 2) && |
| frames_to_process <= input_bus->length(); |
| DCHECK(is_input_safe); |
| if (!is_input_safe) |
| return; |
| |
| unsigned number_of_input_channels = input_bus->NumberOfChannels(); |
| |
| bool is_output_safe = output_bus && output_bus->NumberOfChannels() == 2 && |
| frames_to_process <= output_bus->length(); |
| DCHECK(is_output_safe); |
| if (!is_output_safe) |
| return; |
| |
| const float* source_l = input_bus->Channel(0)->Data(); |
| const float* source_r = |
| number_of_input_channels > 1 ? input_bus->Channel(1)->Data() : source_l; |
| float* destination_l = |
| output_bus->ChannelByType(AudioBus::kChannelLeft)->MutableData(); |
| float* destination_r = |
| output_bus->ChannelByType(AudioBus::kChannelRight)->MutableData(); |
| |
| if (!source_l || !source_r || !destination_l || !destination_r) |
| 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 desired_pan_position; |
| double desired_gain_l; |
| double desired_gain_r; |
| |
| if (number_of_input_channels == 1) { // For mono source case. |
| // Pan smoothly from left to right with azimuth going from -90 -> +90 |
| // degrees. |
| desired_pan_position = (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. |
| desired_pan_position = (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. |
| desired_pan_position = azimuth / 90; |
| } |
| } |
| |
| desired_gain_l = std::cos(kPiOverTwoDouble * desired_pan_position); |
| desired_gain_r = std::sin(kPiOverTwoDouble * desired_pan_position); |
| |
| int n = frames_to_process; |
| |
| if (number_of_input_channels == 1) { // For mono source case. |
| while (n--) { |
| float input_l = *source_l++; |
| |
| *destination_l++ = static_cast<float>(input_l * desired_gain_l); |
| *destination_r++ = static_cast<float>(input_l * desired_gain_r); |
| } |
| } else { // For stereo source case. |
| if (azimuth <= 0) { // from -90 -> 0 |
| while (n--) { |
| float input_l = *source_l++; |
| float input_r = *source_r++; |
| |
| *destination_l++ = |
| static_cast<float>(input_l + input_r * desired_gain_l); |
| *destination_r++ = static_cast<float>(input_r * desired_gain_r); |
| } |
| } else { // from 0 -> +90 |
| while (n--) { |
| float input_l = *source_l++; |
| float input_r = *source_r++; |
| |
| *destination_l++ = static_cast<float>(input_l * desired_gain_l); |
| *destination_r++ = |
| static_cast<float>(input_r + input_l * desired_gain_r); |
| } |
| } |
| } |
| } |
| |
| void EqualPowerPanner::CalculateDesiredGain(double& desired_gain_l, |
| double& desired_gain_r, |
| double azimuth, |
| int number_of_input_channels) { |
| // 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 desired_pan_position; |
| |
| if (number_of_input_channels == 1) { // For mono source case. |
| // Pan smoothly from left to right with azimuth going from -90 -> +90 |
| // degrees. |
| desired_pan_position = (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. |
| desired_pan_position = (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. |
| desired_pan_position = azimuth / 90; |
| } |
| } |
| |
| desired_gain_l = std::cos(kPiOverTwoDouble * desired_pan_position); |
| desired_gain_r = std::sin(kPiOverTwoDouble * desired_pan_position); |
| } |
| |
| void EqualPowerPanner::PanWithSampleAccurateValues( |
| double* azimuth, |
| double* /*elevation*/, |
| const AudioBus* input_bus, |
| AudioBus* output_bus, |
| size_t frames_to_process, |
| AudioBus::ChannelInterpretation) { |
| bool is_input_safe = input_bus && |
| (input_bus->NumberOfChannels() == 1 || |
| input_bus->NumberOfChannels() == 2) && |
| frames_to_process <= input_bus->length(); |
| DCHECK(is_input_safe); |
| if (!is_input_safe) |
| return; |
| |
| unsigned number_of_input_channels = input_bus->NumberOfChannels(); |
| |
| bool is_output_safe = output_bus && output_bus->NumberOfChannels() == 2 && |
| frames_to_process <= output_bus->length(); |
| DCHECK(is_output_safe); |
| if (!is_output_safe) |
| return; |
| |
| const float* source_l = input_bus->Channel(0)->Data(); |
| const float* source_r = |
| number_of_input_channels > 1 ? input_bus->Channel(1)->Data() : source_l; |
| float* destination_l = |
| output_bus->ChannelByType(AudioBus::kChannelLeft)->MutableData(); |
| float* destination_r = |
| output_bus->ChannelByType(AudioBus::kChannelRight)->MutableData(); |
| |
| if (!source_l || !source_r || !destination_l || !destination_r) |
| return; |
| |
| int n = frames_to_process; |
| |
| if (number_of_input_channels == 1) { // For mono source case. |
| for (int k = 0; k < n; ++k) { |
| double desired_gain_l; |
| double desired_gain_r; |
| float input_l = *source_l++; |
| |
| CalculateDesiredGain(desired_gain_l, desired_gain_r, azimuth[k], |
| number_of_input_channels); |
| *destination_l++ = static_cast<float>(input_l * desired_gain_l); |
| *destination_r++ = static_cast<float>(input_l * desired_gain_r); |
| } |
| } else { // For stereo source case. |
| for (int k = 0; k < n; ++k) { |
| double desired_gain_l; |
| double desired_gain_r; |
| |
| CalculateDesiredGain(desired_gain_l, desired_gain_r, azimuth[k], |
| number_of_input_channels); |
| if (azimuth[k] <= 0) { // from -90 -> 0 |
| float input_l = *source_l++; |
| float input_r = *source_r++; |
| *destination_l++ = |
| static_cast<float>(input_l + input_r * desired_gain_l); |
| *destination_r++ = static_cast<float>(input_r * desired_gain_r); |
| } else { // from 0 -> +90 |
| float input_l = *source_l++; |
| float input_r = *source_r++; |
| *destination_l++ = static_cast<float>(input_l * desired_gain_l); |
| *destination_r++ = |
| static_cast<float>(input_r + input_l * desired_gain_r); |
| } |
| } |
| } |
| } |
| |
| } // namespace blink |
