AudioResampler.h revision 01d3acba9de861cb2b718338e787cff3566fc5ec
18123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes/* 28123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * Copyright (C) 2007 The Android Open Source Project 38123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * 48123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * Licensed under the Apache License, Version 2.0 (the "License"); 58123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * you may not use this file except in compliance with the License. 68123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * You may obtain a copy of the License at 78123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * 88123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * http://www.apache.org/licenses/LICENSE-2.0 98123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * 108123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * Unless required by applicable law or agreed to in writing, software 118123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * distributed under the License is distributed on an "AS IS" BASIS, 128123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 138123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * See the License for the specific language governing permissions and 148123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes * limitations under the License. 158123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes */ 168123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 178123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes#ifndef ANDROID_AUDIO_RESAMPLER_H 188123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes#define ANDROID_AUDIO_RESAMPLER_H 19de9f38cc4a30b33ac46b105edf470fbc4a044e99Chris Banes 208123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes#include <stdint.h> 21de9f38cc4a30b33ac46b105edf470fbc4a044e99Chris Banes#include <sys/types.h> 228123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes#include <cutils/compiler.h> 238123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 248123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes#include <media/AudioBufferProvider.h> 258123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 268123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banesnamespace android { 278123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes// ---------------------------------------------------------------------------- 288123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 29de9f38cc4a30b33ac46b105edf470fbc4a044e99Chris Banesclass ANDROID_API AudioResampler { 30de9f38cc4a30b33ac46b105edf470fbc4a044e99Chris Banespublic: 318123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // Determines quality of SRC. 328123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // LOW_QUALITY: linear interpolator (1st order) 338123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // MED_QUALITY: cubic interpolator (3rd order) 348123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // HIGH_QUALITY: fixed multi-tap FIR (e.g. 48KHz->44.1KHz) 358123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // NOTE: high quality SRC will only be supported for 368123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // certain fixed rate conversions. Sample rate cannot be 378123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes // changed dynamically. 388123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes enum src_quality { 398123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes DEFAULT_QUALITY=0, 408123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes LOW_QUALITY=1, 418123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes MED_QUALITY=2, 428123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes HIGH_QUALITY=3, 438123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes VERY_HIGH_QUALITY=4, 444c2a95906254748cb9a843b061288265d6e185a9Chris Banes DYN_LOW_QUALITY=5, 458123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes DYN_MED_QUALITY=6, 468123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes DYN_HIGH_QUALITY=7, 478123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes }; 488123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 498123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes static AudioResampler* create(int bitDepth, int inChannelCount, 508123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes int32_t sampleRate, src_quality quality=DEFAULT_QUALITY); 518123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes 528123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes virtual ~AudioResampler(); 534c2a95906254748cb9a843b061288265d6e185a9Chris Banes 548123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes virtual void init() = 0; 558123e4b3d19031e34a60c0db202f0b3d100eb9d8Chris Banes virtual void setSampleRate(int32_t inSampleRate); 56 virtual void setVolume(int16_t left, int16_t right); 57 virtual void setLocalTimeFreq(uint64_t freq); 58 59 // set the PTS of the next buffer output by the resampler 60 virtual void setPTS(int64_t pts); 61 62 // Resample int16_t samples from provider and accumulate into 'out'. 63 // A mono provider delivers a sequence of samples. 64 // A stereo provider delivers a sequence of interleaved pairs of samples. 65 // Multi-channel providers are not supported. 66 // In either case, 'out' holds interleaved pairs of fixed-point signed Q19.12. 67 // That is, for a mono provider, there is an implicit up-channeling. 68 // Since this method accumulates, the caller is responsible for clearing 'out' initially. 69 // FIXME assumes provider is always successful; it should return the actual frame count. 70 virtual void resample(int32_t* out, size_t outFrameCount, 71 AudioBufferProvider* provider) = 0; 72 73 virtual void reset(); 74 virtual size_t getUnreleasedFrames() const { return mInputIndex; } 75 76 // called from destructor, so must not be virtual 77 src_quality getQuality() const { return mQuality; } 78 79protected: 80 // number of bits for phase fraction - 30 bits allows nearly 2x downsampling 81 static const int kNumPhaseBits = 30; 82 83 // phase mask for fraction 84 static const uint32_t kPhaseMask = (1LU<<kNumPhaseBits)-1; 85 86 // multiplier to calculate fixed point phase increment 87 static const double kPhaseMultiplier; 88 89 AudioResampler(int bitDepth, int inChannelCount, int32_t sampleRate, src_quality quality); 90 91 // prevent copying 92 AudioResampler(const AudioResampler&); 93 AudioResampler& operator=(const AudioResampler&); 94 95 int64_t calculateOutputPTS(int outputFrameIndex); 96 97 const int32_t mBitDepth; 98 const int32_t mChannelCount; 99 const int32_t mSampleRate; 100 int32_t mInSampleRate; 101 AudioBufferProvider::Buffer mBuffer; 102 union { 103 int16_t mVolume[2]; 104 uint32_t mVolumeRL; 105 }; 106 int16_t mTargetVolume[2]; 107 size_t mInputIndex; 108 int32_t mPhaseIncrement; 109 uint32_t mPhaseFraction; 110 uint64_t mLocalTimeFreq; 111 int64_t mPTS; 112 113private: 114 const src_quality mQuality; 115 116 // Return 'true' if the quality level is supported without explicit request 117 static bool qualityIsSupported(src_quality quality); 118 119 // For pthread_once() 120 static void init_routine(); 121 122 // Return the estimated CPU load for specific resampler in MHz. 123 // The absolute number is irrelevant, it's the relative values that matter. 124 static uint32_t qualityMHz(src_quality quality); 125}; 126 127// ---------------------------------------------------------------------------- 128} 129; // namespace android 130 131#endif // ANDROID_AUDIO_RESAMPLER_H 132