1ffe9c25ce85e1af55d58ec025adc6367d70db7e8Eric Laurent/* 2135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** 3135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** Copyright 2009, The Android Open Source Project 4135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** 5135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** Licensed under the Apache License, Version 2.0 (the "License"); 6135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** you may not use this file except in compliance with the License. 7135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** You may obtain a copy of the License at 8135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** 9135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** http://www.apache.org/licenses/LICENSE-2.0 10135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** 11135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** Unless required by applicable law or agreed to in writing, software 12135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** distributed under the License is distributed on an "AS IS" BASIS, 13135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** See the License for the specific language governing permissions and 15135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent** limitations under the License. 16135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent*/ 17135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 18135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent#ifndef ANDROID_AUDIO_COMMON_H 19135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent#define ANDROID_AUDIO_COMMON_H 20135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 21135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent#include <stdint.h> 22135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent#include <stddef.h> 23f6b1678f8f508b447155a81b44e214475ab634a8Glenn Kasten#include <cutils/compiler.h> 24135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 25135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentnamespace android { 26135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 27135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Audio coefficient type. 28135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurenttypedef int32_t audio_coef_t; 29135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Audio sample type. 30135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurenttypedef int32_t audio_sample_t; 31135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Accumulator type for coef x sample. 32135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurenttypedef int64_t audio_coef_sample_acc_t; 33135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 34135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Number of fraction bits for audio coefficient. 35135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentstatic const int AUDIO_COEF_PRECISION = 24; 36135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Audio coefficient with the value of 1.0 37135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentstatic const audio_coef_t AUDIO_COEF_ONE = 1 << AUDIO_COEF_PRECISION; 38135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Audio coefficient with the value of 0.5 39135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentstatic const audio_coef_t AUDIO_COEF_HALF = 1 << (AUDIO_COEF_PRECISION - 1); 40135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Number of fraction bits for audio sample. 41135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentstatic const int AUDIO_SAMPLE_PRECISION = 24; 42135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Audio sample with the value of 1.0 43135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentstatic const audio_sample_t AUDIO_SAMPLE_ONE = 1 << AUDIO_SAMPLE_PRECISION; 44135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 45135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// TODO: These are just temporary naive implementations of the necessary 46135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// arithmetic operations needed for the filter. They should be moved to a more 47135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// generic location and implemented more efficiently. 48135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 49135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Multiply a sample by a coefficient to return an accumulator. 50135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline audio_coef_sample_acc_t mul_coef_sample(audio_coef_t x, audio_sample_t y) { 51135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return ((audio_coef_sample_acc_t) (x)) * y; 52135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 53135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 54135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Multiply and accumulate sample by a coefficient to return an accumulator. 55135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline audio_coef_sample_acc_t mac_coef_sample(audio_coef_t x, audio_sample_t y, audio_coef_sample_acc_t acc) { 56135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return acc + ((audio_coef_sample_acc_t) (x)) * y; 57135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 58135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 59135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Convert a sample-coefficient accumulator to a sample. 60135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline audio_sample_t coef_sample_acc_to_sample(audio_coef_sample_acc_t acc) { 61135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent if (acc < 0) { 62135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent acc += AUDIO_COEF_ONE - 1; 63135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent } 64135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return (audio_sample_t) (acc >> AUDIO_COEF_PRECISION); 65135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 66135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 67135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Convert a S15 sample to audio_sample_t 68135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline audio_sample_t s15_to_audio_sample_t(int16_t s15) { 69135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return audio_sample_t(s15) << 9; 70135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 71135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 72135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Convert a audio_sample_t sample to S15 (no clipping) 73135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline int16_t audio_sample_t_to_s15(audio_sample_t sample) { 74135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return int16_t((sample + (1 << 8)) >> 9); 75135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 76135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 77135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent// Convert a audio_sample_t sample to S15 (with clipping) 78135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurentinline int16_t audio_sample_t_to_s15_clip(audio_sample_t sample) { 79135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent // TODO: optimize for targets supporting this as an atomic operation. 80f6b1678f8f508b447155a81b44e214475ab634a8Glenn Kasten if (CC_UNLIKELY(sample >= (0x7FFF << 9))) { 81135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return 0x7FFF; 82f6b1678f8f508b447155a81b44e214475ab634a8Glenn Kasten } else if (CC_UNLIKELY(sample <= -(0x8000 << 9))) { 83135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return 0x8000; 84135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent } else { 85135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent return audio_sample_t_to_s15(sample); 86135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent } 87135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 88135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 89135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent//////////////////////////////////////////////////////////////////////////////// 90135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 91135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent} 92135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent 93135ad07e33d30e5202deb21061a0e3ecf0ffad35Eric Laurent#endif // ANDROID_AUDIO_COMMON_H 94