libavcodec/opt.h

   1 /*
   2  * AVOptions
   3  * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
   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 FFMPEG_OPT_H
  23 #define FFMPEG_OPT_H
  24
  25 /**
  26  * @file opt.h
  27  * AVOptions
  28  */
  29
  30 #include "libavutil/rational.h"
  31
  32 enum AVOptionType{
  33     FF_OPT_TYPE_FLAGS,
  34     FF_OPT_TYPE_INT,
  35     FF_OPT_TYPE_INT64,
  36     FF_OPT_TYPE_DOUBLE,
  37     FF_OPT_TYPE_FLOAT,
  38     FF_OPT_TYPE_STRING,
  39     FF_OPT_TYPE_RATIONAL,
  40     FF_OPT_TYPE_BINARY,  ///< offset must point to a pointer immediately followed by an int for the length
  41     FF_OPT_TYPE_CONST=128,
  42 };
  43
  44 /**
  45  * AVOption
  46  */
  47 typedef struct AVOption {
  48     const char *name;
  49
  50     /**
  51      * short English help text
  52      * @todo What about other languages?
  53      */
  54     const char *help;
  55
  56     /**
  57      * The offset relative to the context structure where the option
  58      * value is stored. It should be 0 for named constants.
  59      */
  60     int offset;
  61     enum AVOptionType type;
  62
  63     /**
  64      * the default value for scalar options
  65      */
  66     double default_val;
  67     double min;                 ///< minimum valid value for the option
  68     double max;                 ///< maximum valid value for the option
  69
  70     int flags;
  71 #define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
  72 #define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
  73 #define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
  74 #define AV_OPT_FLAG_AUDIO_PARAM     8
  75 #define AV_OPT_FLAG_VIDEO_PARAM     16
  76 #define AV_OPT_FLAG_SUBTITLE_PARAM  32
  77 //FIXME think about enc-audio, ... style flags
  78
  79     /**
  80      * The logical unit to which the option belongs. Non-constant
  81      * options and corresponding named constants share the same
  82      * unit. May be NULL.
  83      */
  84     const char *unit;
  85 } AVOption;
  86
  87
  88 const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
  89 const AVOption *av_set_string(void *obj, const char *name, const char *val);
  90 const AVOption *av_set_double(void *obj, const char *name, double n);
  91 const AVOption *av_set_q(void *obj, const char *name, AVRational n);
  92 const AVOption *av_set_int(void *obj, const char *name, int64_t n);
  93 double av_get_double(void *obj, const char *name, const AVOption **o_out);
  94 AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
  95 int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
  96 const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
  97 const AVOption *av_next_option(void *obj, const AVOption *last);
  98 int av_opt_show(void *obj, void *av_log_obj);
  99 void av_opt_set_defaults(void *s);
 100 void av_opt_set_defaults2(void *s, int mask, int flags);
 101
 102 #endif /* FFMPEG_OPT_H */