1/* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef ANDROID_AUDIO_CONVERSION_H 18#define ANDROID_AUDIO_CONVERSION_H 19#include <stdint.h> 20#include <sys/cdefs.h> 21#include <system/audio.h> 22 23/** \cond */ 24__BEGIN_DECLS 25/** \endcond */ 26 27// for in-place conversion routines 28 29/** 30 * In-place mono blend using the arithmetic average of the channels in each audio frame. 31 * 32 * \param buf buffer of frames 33 * \param format one of AUDIO_FORMAT_PCM_16_BIT or AUDIO_FORMAT_PCM_FLOAT 34 * \param channelCount number of channels per frame 35 * \param frames number of frames in buffer 36 * \param limit whether to use a limiter (experimental, currently only for stereo float) 37 * 38 * \return 39 * none 40 * 41 */ 42 43void mono_blend(void *buf, audio_format_t format, size_t channelCount, size_t frames, 44 bool limit = false); 45 46/** \cond */ 47__END_DECLS 48/** \endcond */ 49 50#endif 51