| /* |
| * Copyright (C) 2011 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. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE 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 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. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DYNAMICS_COMPRESSOR_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DYNAMICS_COMPRESSOR_H_ |
| |
| #include <memory> |
| |
| #include "base/macros.h" |
| #include "third_party/blink/renderer/platform/audio/audio_array.h" |
| #include "third_party/blink/renderer/platform/audio/dynamics_compressor_kernel.h" |
| #include "third_party/blink/renderer/platform/wtf/allocator.h" |
| |
| namespace blink { |
| |
| class AudioBus; |
| |
| // DynamicsCompressor implements a flexible audio dynamics compression effect |
| // such as is commonly used in musical production and game audio. It lowers the |
| // volume of the loudest parts of the signal and raises the volume of the |
| // softest parts, making the sound richer, fuller, and more controlled. |
| |
| class PLATFORM_EXPORT DynamicsCompressor { |
| USING_FAST_MALLOC(DynamicsCompressor); |
| |
| public: |
| enum { |
| kParamThreshold, |
| kParamKnee, |
| kParamRatio, |
| kParamAttack, |
| kParamRelease, |
| kParamPreDelay, |
| kParamReleaseZone1, |
| kParamReleaseZone2, |
| kParamReleaseZone3, |
| kParamReleaseZone4, |
| kParamPostGain, |
| kParamFilterStageGain, |
| kParamFilterStageRatio, |
| kParamFilterAnchor, |
| kParamEffectBlend, |
| kParamReduction, |
| kParamLast |
| }; |
| |
| DynamicsCompressor(float sample_rate, unsigned number_of_channels); |
| |
| void Process(const AudioBus* source_bus, |
| AudioBus* destination_bus, |
| unsigned frames_to_process); |
| void Reset(); |
| void SetNumberOfChannels(unsigned); |
| |
| void SetParameterValue(unsigned parameter_id, float value); |
| float ParameterValue(unsigned parameter_id); |
| |
| float SampleRate() const { return sample_rate_; } |
| float Nyquist() const { return sample_rate_ / 2; } |
| |
| double TailTime() const; |
| double LatencyTime() const { |
| return compressor_.LatencyFrames() / static_cast<double>(SampleRate()); |
| } |
| bool RequiresTailProcessing() const { |
| // Always return true even if the tail time and latency might both be zero. |
| return true; |
| } |
| |
| protected: |
| unsigned number_of_channels_; |
| |
| // m_parameters holds the tweakable compressor parameters. |
| float parameters_[kParamLast]; |
| void InitializeParameters(); |
| |
| float sample_rate_; |
| |
| // Emphasis filter controls. |
| float last_filter_stage_ratio_; |
| float last_anchor_; |
| float last_filter_stage_gain_; |
| |
| std::unique_ptr<const float* []> source_channels_; |
| std::unique_ptr<float* []> destination_channels_; |
| |
| // The core compressor. |
| DynamicsCompressorKernel compressor_; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(DynamicsCompressor); |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DYNAMICS_COMPRESSOR_H_ |