165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian/* 265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * Copyright (C) 2007 The Android Open Source Project 365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * 465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * Licensed under the Apache License, Version 2.0 (the "License"); 565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * you may not use this file except in compliance with the License. 665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * You may obtain a copy of the License at 765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * 865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * http://www.apache.org/licenses/LICENSE-2.0 965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * 1065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * Unless required by applicable law or agreed to in writing, software 1165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * distributed under the License is distributed on an "AS IS" BASIS, 1265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * See the License for the specific language governing permissions and 1465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian * limitations under the License. 1565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian */ 1665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 1765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#ifndef ANDROID_AUDIO_RESAMPLER_H 1865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#define ANDROID_AUDIO_RESAMPLER_H 1965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 2065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#include <stdint.h> 2165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#include <sys/types.h> 2236802bd18b7b4e8c87fa019c7e3068bee330d174Dan Albert 23e762be91c3280d837b1d48455cba90459ced7511Mathias Agopian#include <cutils/compiler.h> 2436802bd18b7b4e8c87fa019c7e3068bee330d174Dan Albert#include <utils/Compat.h> 2565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 262dd4bdd715f586d4d30cf90cc6fc2bbfbce60fe0Glenn Kasten#include <media/AudioBufferProvider.h> 273348e36c51e91e78020bcc6578eda83d97c31becAndy Hung#include <system/audio.h> 2865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 2965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopiannamespace android { 3065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian// ---------------------------------------------------------------------------- 3165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 32e762be91c3280d837b1d48455cba90459ced7511Mathias Agopianclass ANDROID_API AudioResampler { 3365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopianpublic: 3465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // Determines quality of SRC. 3565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // LOW_QUALITY: linear interpolator (1st order) 3665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // MED_QUALITY: cubic interpolator (3rd order) 3765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // HIGH_QUALITY: fixed multi-tap FIR (e.g. 48KHz->44.1KHz) 3865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // NOTE: high quality SRC will only be supported for 3965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // certain fixed rate conversions. Sample rate cannot be 40e53b9ead781c36e96d6b6f012ddffc93a3d80f0dGlenn Kasten // changed dynamically. 4165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian enum src_quality { 42ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten DEFAULT_QUALITY=0, 4365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian LOW_QUALITY=1, 4465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian MED_QUALITY=2, 4576b111685010e1fea7c0a865c038aee35507fde4SathishKumar Mani HIGH_QUALITY=3, 46ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten VERY_HIGH_QUALITY=4, 4786eae0e5931103e040ac2cdd023ef5db252e09f6Andy Hung DYN_LOW_QUALITY=5, 4886eae0e5931103e040ac2cdd023ef5db252e09f6Andy Hung DYN_MED_QUALITY=6, 4986eae0e5931103e040ac2cdd023ef5db252e09f6Andy Hung DYN_HIGH_QUALITY=7, 5065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian }; 5165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 5236802bd18b7b4e8c87fa019c7e3068bee330d174Dan Albert static const CONSTEXPR float UNITY_GAIN_FLOAT = 1.0f; 535e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung 543348e36c51e91e78020bcc6578eda83d97c31becAndy Hung static AudioResampler* create(audio_format_t format, int inChannelCount, 55ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten int32_t sampleRate, src_quality quality=DEFAULT_QUALITY); 5665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 5765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual ~AudioResampler(); 5865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 5965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void init() = 0; 6065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void setSampleRate(int32_t inSampleRate); 615e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung virtual void setVolume(float left, float right); 6265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 6334af02647b387a252fb02bab8e2cb9f7bd9c8abbGlenn Kasten // Resample int16_t samples from provider and accumulate into 'out'. 6434af02647b387a252fb02bab8e2cb9f7bd9c8abbGlenn Kasten // A mono provider delivers a sequence of samples. 6534af02647b387a252fb02bab8e2cb9f7bd9c8abbGlenn Kasten // A stereo provider delivers a sequence of interleaved pairs of samples. 666b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // 6784a0c6e87c48f58a0d3be71961432c086a4d24ccAndy Hung // In either case, 'out' holds interleaved pairs of fixed-point Q4.27. 6834af02647b387a252fb02bab8e2cb9f7bd9c8abbGlenn Kasten // That is, for a mono provider, there is an implicit up-channeling. 6934af02647b387a252fb02bab8e2cb9f7bd9c8abbGlenn Kasten // Since this method accumulates, the caller is responsible for clearing 'out' initially. 706b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // 716b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // For a float resampler, 'out' holds interleaved pairs of float samples. 726b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // 736b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // Multichannel interleaved frames for n > 2 is supported for quality DYN_LOW_QUALITY, 746b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // DYN_MED_QUALITY, and DYN_HIGH_QUALITY. 756b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // 766b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung // Returns the number of frames resampled into the out buffer. 776b3b7e304e0f8f167241b2c75f1eb04a9ef192ecAndy Hung virtual size_t resample(int32_t* out, size_t outFrameCount, 7865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioBufferProvider* provider) = 0; 7965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 80243f5f91755c01614a8cafe90b0806396e22d553Eric Laurent virtual void reset(); 81c59c004a3a6042c0990d71179f88eee2ce781e3cGlenn Kasten virtual size_t getUnreleasedFrames() const { return mInputIndex; } 82243f5f91755c01614a8cafe90b0806396e22d553Eric Laurent 83ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten // called from destructor, so must not be virtual 84ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten src_quality getQuality() const { return mQuality; } 85ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten 8665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopianprotected: 8765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // number of bits for phase fraction - 30 bits allows nearly 2x downsampling 8865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static const int kNumPhaseBits = 30; 8965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 9065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // phase mask for fraction 9165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static const uint32_t kPhaseMask = (1LU<<kNumPhaseBits)-1; 9265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 9365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // multiplier to calculate fixed point phase increment 9401d3acba9de861cb2b718338e787cff3566fc5ecGlenn Kasten static const double kPhaseMultiplier; 9565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 963348e36c51e91e78020bcc6578eda83d97c31becAndy Hung AudioResampler(int inChannelCount, int32_t sampleRate, src_quality quality); 9765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 9865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // prevent copying 9965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioResampler(const AudioResampler&); 10065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioResampler& operator=(const AudioResampler&); 10165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 102004f719467c498942c40de9f260be601ee45e630Glenn Kasten const int32_t mChannelCount; 103004f719467c498942c40de9f260be601ee45e630Glenn Kasten const int32_t mSampleRate; 10465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mInSampleRate; 10565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioBufferProvider::Buffer mBuffer; 10665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian union { 10765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int16_t mVolume[2]; 10865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian uint32_t mVolumeRL; 10965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian }; 11065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int16_t mTargetVolume[2]; 11165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian size_t mInputIndex; 11265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mPhaseIncrement; 11365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian uint32_t mPhaseFraction; 114ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten 11524781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // returns the inFrameCount required to generate outFrameCount frames. 11624781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 11724781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // Placed here to be a consistent for all resamplers. 11824781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 11924781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // Right now, we use the upper bound without regards to the current state of the 12024781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // input buffer using integer arithmetic, as follows: 12124781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 12224781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // (static_cast<uint64_t>(outFrameCount)*mInSampleRate + (mSampleRate - 1))/mSampleRate; 12324781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 12424781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // The double precision equivalent (float may not be precise enough): 12524781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // ceil(static_cast<double>(outFrameCount) * mInSampleRate / mSampleRate); 12624781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 12724781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // this relies on the fact that the mPhaseIncrement is rounded down from 12824781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // #phases * mInSampleRate/mSampleRate and the fact that Sum(Floor(x)) <= Floor(Sum(x)). 12924781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // http://www.proofwiki.org/wiki/Sum_of_Floors_Not_Greater_Than_Floor_of_Sums 13024781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 13124781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // (so long as double precision is computed accurately enough to be considered 13224781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // greater than or equal to the Floor(x) value in int32_t arithmetic; thus this 13324781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // will not necessarily hold for floats). 13424781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 13524781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // TODO: 13624781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // Greater accuracy and a tight bound is obtained by: 13724781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 1) subtract and adjust for the current state of the AudioBufferProvider buffer. 13824781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 2) using the exact integer formula where (ignoring 64b casting) 13924781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // inFrameCount = (mPhaseIncrement * (outFrameCount - 1) + mPhaseFraction) / phaseWrapLimit; 14024781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // phaseWrapLimit is the wraparound (1 << kNumPhaseBits), if not specified explicitly. 14124781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung // 14224781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung inline size_t getInFrameCountRequired(size_t outFrameCount) { 14324781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung return (static_cast<uint64_t>(outFrameCount)*mInSampleRate 14424781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung + (mSampleRate - 1))/mSampleRate; 14524781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung } 14624781fff62a4cf7279d3dac83c33e2ac612712baAndy Hung 1475e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung inline float clampFloatVol(float volume) { 1485e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung if (volume > UNITY_GAIN_FLOAT) { 1495e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung return UNITY_GAIN_FLOAT; 1505e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung } else if (volume >= 0.) { 1515e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung return volume; 1525e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung } 1535e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung return 0.; // NaN or negative volume maps to 0. 1545e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung } 1555e58b0abe5b6c8f5bd96a8f78bbeeeb4d3892020Andy Hung 156ac6020508acedd316391dee42329040bf45f8d90Glenn Kastenprivate: 157ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten const src_quality mQuality; 158ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten 159ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten // Return 'true' if the quality level is supported without explicit request 160ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten static bool qualityIsSupported(src_quality quality); 161ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten 162ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten // For pthread_once() 163ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten static void init_routine(); 164ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten 165ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten // Return the estimated CPU load for specific resampler in MHz. 166ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten // The absolute number is irrelevant, it's the relative values that matter. 167ac6020508acedd316391dee42329040bf45f8d90Glenn Kasten static uint32_t qualityMHz(src_quality quality); 16865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian}; 16965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 17065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian// ---------------------------------------------------------------------------- 17163238efb0d674758902918e3cdaac322126484b7Glenn Kasten} // namespace android 17265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 17365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#endif // ANDROID_AUDIO_RESAMPLER_H 174