1/* 2 * audio conversion 3 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 4 * Copyright (c) 2008 Peter Ross 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#ifndef AVCODEC_AUDIOCONVERT_H 24#define AVCODEC_AUDIOCONVERT_H 25 26/** 27 * @file libavcodec/audioconvert.h 28 * Audio format conversion routines 29 */ 30 31 32#include "avcodec.h" 33 34 35/** 36 * Generate string corresponding to the sample format with 37 * number sample_fmt, or a header if sample_fmt is negative. 38 * 39 * @param[in] buf the buffer where to write the string 40 * @param[in] buf_size the size of buf 41 * @param[in] sample_fmt the number of the sample format to print the corresponding info string, or 42 * a negative value to print the corresponding header. 43 * Meaningful values for obtaining a sample format info vary from 0 to SAMPLE_FMT_NB -1. 44 */ 45void avcodec_sample_fmt_string(char *buf, int buf_size, int sample_fmt); 46 47/** 48 * @return NULL on error 49 */ 50const char *avcodec_get_sample_fmt_name(int sample_fmt); 51 52/** 53 * @return SAMPLE_FMT_NONE on error 54 */ 55enum SampleFormat avcodec_get_sample_fmt(const char* name); 56 57/** 58 * @return NULL on error 59 */ 60const char *avcodec_get_channel_name(int channel_id); 61 62/** 63 * Return description of channel layout 64 */ 65void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout); 66 67/** 68 * Guess the channel layout 69 * @param nb_channels 70 * @param codec_id Codec identifier, or CODEC_ID_NONE if unknown 71 * @param fmt_name Format name, or NULL if unknown 72 * @return Channel layout mask 73 */ 74int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name); 75 76 77struct AVAudioConvert; 78typedef struct AVAudioConvert AVAudioConvert; 79 80/** 81 * Create an audio sample format converter context 82 * @param out_fmt Output sample format 83 * @param out_channels Number of output channels 84 * @param in_fmt Input sample format 85 * @param in_channels Number of input channels 86 * @param[in] matrix Channel mixing matrix (of dimension in_channel*out_channels). Set to NULL to ignore. 87 * @param flags See FF_MM_xx 88 * @return NULL on error 89 */ 90AVAudioConvert *av_audio_convert_alloc(enum SampleFormat out_fmt, int out_channels, 91 enum SampleFormat in_fmt, int in_channels, 92 const float *matrix, int flags); 93 94/** 95 * Free audio sample format converter context 96 */ 97void av_audio_convert_free(AVAudioConvert *ctx); 98 99/** 100 * Convert between audio sample formats 101 * @param[in] out array of output buffers for each channel. set to NULL to ignore processing of the given channel. 102 * @param[in] out_stride distance between consecutive input samples (measured in bytes) 103 * @param[in] in array of input buffers for each channel 104 * @param[in] in_stride distance between consecutive output samples (measured in bytes) 105 * @param len length of audio frame size (measured in samples) 106 */ 107int av_audio_convert(AVAudioConvert *ctx, 108 void * const out[6], const int out_stride[6], 109 const void * const in[6], const int in_stride[6], int len); 110 111#endif /* AVCODEC_AUDIOCONVERT_H */ 112