AudioResampler.h revision 65ab47156e1c7dfcd8cc4266253a5ff30219e7f0
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> 2265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 2365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#include "AudioBufferProvider.h" 2465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 2565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopiannamespace android { 2665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian// ---------------------------------------------------------------------------- 2765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 2865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopianclass AudioResampler { 2965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopianpublic: 3065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // Determines quality of SRC. 3165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // LOW_QUALITY: linear interpolator (1st order) 3265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // MED_QUALITY: cubic interpolator (3rd order) 3365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // HIGH_QUALITY: fixed multi-tap FIR (e.g. 48KHz->44.1KHz) 3465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // NOTE: high quality SRC will only be supported for 3565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // certain fixed rate conversions. Sample rate cannot be 3665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // changed dynamically. 3765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian enum src_quality { 3865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian DEFAULT=0, 3965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian LOW_QUALITY=1, 4065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian MED_QUALITY=2, 4165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian HIGH_QUALITY=3 4265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian }; 4365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 4465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static AudioResampler* create(int bitDepth, int inChannelCount, 4565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t sampleRate, int quality=DEFAULT); 4665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 4765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual ~AudioResampler(); 4865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 4965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void init() = 0; 5065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void setSampleRate(int32_t inSampleRate); 5165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void setVolume(int16_t left, int16_t right); 5265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 5365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian virtual void resample(int32_t* out, size_t outFrameCount, 5465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioBufferProvider* provider) = 0; 5565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 5665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopianprotected: 5765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // number of bits for phase fraction - 30 bits allows nearly 2x downsampling 5865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static const int kNumPhaseBits = 30; 5965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 6065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // phase mask for fraction 6165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static const uint32_t kPhaseMask = (1LU<<kNumPhaseBits)-1; 6265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 6365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // multiplier to calculate fixed point phase increment 6465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian static const double kPhaseMultiplier = 1L << kNumPhaseBits; 6565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 6665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian enum format {MONO_16_BIT, STEREO_16_BIT}; 6765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioResampler(int bitDepth, int inChannelCount, int32_t sampleRate); 6865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 6965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian // prevent copying 7065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioResampler(const AudioResampler&); 7165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioResampler& operator=(const AudioResampler&); 7265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 7365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mBitDepth; 7465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mChannelCount; 7565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mSampleRate; 7665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mInSampleRate; 7765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian AudioBufferProvider::Buffer mBuffer; 7865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian union { 7965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int16_t mVolume[2]; 8065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian uint32_t mVolumeRL; 8165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian }; 8265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int16_t mTargetVolume[2]; 8365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian format mFormat; 8465ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian size_t mInputIndex; 8565ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian int32_t mPhaseIncrement; 8665ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian uint32_t mPhaseFraction; 8765ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian}; 8865ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 8965ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian// ---------------------------------------------------------------------------- 9065ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian} 9165ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian; // namespace android 9265ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian 9365ab47156e1c7dfcd8cc4266253a5ff30219e7f0Mathias Agopian#endif // ANDROID_AUDIO_RESAMPLER_H 94