libavfilter/audio.h

   1 /*
   2  * Copyright (c) Stefano Sabatini | stefasab at gmail.com
   3  * Copyright (c) S.N. Hemanth Meenakshisundaram | smeenaks at ucsd.edu
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef AVFILTER_AUDIO_H
  23 #define AVFILTER_AUDIO_H
  24
  25 #include "avfilter.h"
  26 #include "filters.h"
  27
  28 /**
  29  * An AVFilterPad array whose only entry has name "default"
  30  * and is of type AVMEDIA_TYPE_AUDIO.
  31  */
  32 extern const AVFilterPad ff_audio_default_filterpad[1];
  33
  34 /** default handler for get_audio_buffer() for audio inputs */
  35 AVFrame *ff_default_get_audio_buffer(AVFilterLink *link, int nb_samples);
  36
  37 /** get_audio_buffer() handler for filters which simply pass audio along */
  38 AVFrame *ff_null_get_audio_buffer(AVFilterLink *link, int nb_samples);
  39
  40 /**
  41  * Request an audio samples buffer with a specific set of permissions.
  42  *
  43  * @param link           the output link to the filter from which the buffer will
  44  *                       be requested
  45  * @param nb_samples     the number of samples per channel
  46  * @return               on success an AVFrame owned by the caller, NULL on error
  47  */
  48 AVFrame *ff_get_audio_buffer(AVFilterLink *link, int nb_samples);
  49
  50 /**
  51  * Parse a sample rate.
  52  *
  53  * @param ret unsigned integer pointer to where the value should be written
  54  * @param arg string to parse
  55  * @param log_ctx log context
  56  * @return >= 0 in case of success, a negative AVERROR code on error
  57  */
  58 av_warn_unused_result
  59 int ff_parse_sample_rate(int *ret, const char *arg, void *log_ctx);
  60
  61 /**
  62  * Parse a channel layout or a corresponding integer representation.
  63  *
  64  * @param ret 64bit integer pointer to where the value should be written.
  65  * @param nret integer pointer to the number of channels;
  66  *             if not NULL, then unknown channel layouts are accepted
  67  * @param arg string to parse
  68  * @param log_ctx log context
  69  * @return >= 0 in case of success, a negative AVERROR code on error
  70  */
  71 av_warn_unused_result
  72 int ff_parse_channel_layout(AVChannelLayout *ret, int *nret, const char *arg,
  73                             void *log_ctx);
  74
  75 #endif /* AVFILTER_AUDIO_H */