opt.h 7.2 KB

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  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. #ifndef AVCODEC_OPT_H
  22. #define AVCODEC_OPT_H
  23. /**
  24. * @file
  25. * AVOptions
  26. */
  27. #include "libavutil/rational.h"
  28. #include "avcodec.h"
  29. enum AVOptionType {
  30. FF_OPT_TYPE_FLAGS,
  31. FF_OPT_TYPE_INT,
  32. FF_OPT_TYPE_INT64,
  33. FF_OPT_TYPE_DOUBLE,
  34. FF_OPT_TYPE_FLOAT,
  35. FF_OPT_TYPE_STRING,
  36. FF_OPT_TYPE_RATIONAL,
  37. FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
  38. FF_OPT_TYPE_CONST=128,
  39. };
  40. /**
  41. * AVOption
  42. */
  43. typedef struct AVOption {
  44. const char *name;
  45. /**
  46. * short English help text
  47. * @todo What about other languages?
  48. */
  49. const char *help;
  50. /**
  51. * The offset relative to the context structure where the option
  52. * value is stored. It should be 0 for named constants.
  53. */
  54. int offset;
  55. enum AVOptionType type;
  56. /**
  57. * the default value for scalar options
  58. */
  59. double default_val;
  60. double min; ///< minimum valid value for the option
  61. double max; ///< maximum valid value for the option
  62. int flags;
  63. #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
  64. #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
  65. #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
  66. #define AV_OPT_FLAG_AUDIO_PARAM 8
  67. #define AV_OPT_FLAG_VIDEO_PARAM 16
  68. #define AV_OPT_FLAG_SUBTITLE_PARAM 32
  69. //FIXME think about enc-audio, ... style flags
  70. /**
  71. * The logical unit to which the option belongs. Non-constant
  72. * options and corresponding named constants share the same
  73. * unit. May be NULL.
  74. */
  75. const char *unit;
  76. } AVOption;
  77. /**
  78. * AVOption2.
  79. * THIS IS NOT PART OF THE API/ABI YET!
  80. * This is identical to AVOption except that default_val was replaced by
  81. * an union, it should be compatible with AVOption on normal platforms.
  82. */
  83. typedef struct AVOption2 {
  84. const char *name;
  85. /**
  86. * short English help text
  87. * @todo What about other languages?
  88. */
  89. const char *help;
  90. /**
  91. * The offset relative to the context structure where the option
  92. * value is stored. It should be 0 for named constants.
  93. */
  94. int offset;
  95. enum AVOptionType type;
  96. /**
  97. * the default value for scalar options
  98. */
  99. union {
  100. double dbl;
  101. const char *str;
  102. } default_val;
  103. double min; ///< minimum valid value for the option
  104. double max; ///< maximum valid value for the option
  105. int flags;
  106. /*
  107. #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
  108. #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
  109. #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
  110. #define AV_OPT_FLAG_AUDIO_PARAM 8
  111. #define AV_OPT_FLAG_VIDEO_PARAM 16
  112. #define AV_OPT_FLAG_SUBTITLE_PARAM 32
  113. */
  114. //FIXME think about enc-audio, ... style flags
  115. /**
  116. * The logical unit to which the option belongs. Non-constant
  117. * options and corresponding named constants share the same
  118. * unit. May be NULL.
  119. */
  120. const char *unit;
  121. } AVOption2;
  122. /**
  123. * Look for an option in obj. Look only for the options which
  124. * have the flags set as specified in mask and flags (that is,
  125. * for which it is the case that opt->flags & mask == flags).
  126. *
  127. * @param[in] obj a pointer to a struct whose first element is a
  128. * pointer to an AVClass
  129. * @param[in] name the name of the option to look for
  130. * @param[in] unit the unit of the option to look for, or any if NULL
  131. * @return a pointer to the option found, or NULL if no option
  132. * has been found
  133. */
  134. const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
  135. #if LIBAVCODEC_VERSION_MAJOR < 53
  136. /**
  137. * @see av_set_string2()
  138. */
  139. attribute_deprecated const AVOption *av_set_string(void *obj, const char *name, const char *val);
  140. /**
  141. * @return a pointer to the AVOption corresponding to the field set or
  142. * NULL if no matching AVOption exists, or if the value val is not
  143. * valid
  144. * @see av_set_string3()
  145. */
  146. attribute_deprecated const AVOption *av_set_string2(void *obj, const char *name, const char *val, int alloc);
  147. #endif
  148. /**
  149. * Set the field of obj with the given name to value.
  150. *
  151. * @param[in] obj A struct whose first element is a pointer to an
  152. * AVClass.
  153. * @param[in] name the name of the field to set
  154. * @param[in] val The value to set. If the field is not of a string
  155. * type, then the given string is parsed.
  156. * SI postfixes and some named scalars are supported.
  157. * If the field is of a numeric type, it has to be a numeric or named
  158. * scalar. Behavior with more than one scalar and +- infix operators
  159. * is undefined.
  160. * If the field is of a flags type, it has to be a sequence of numeric
  161. * scalars or named flags separated by '+' or '-'. Prefixing a flag
  162. * with '+' causes it to be set without affecting the other flags;
  163. * similarly, '-' unsets a flag.
  164. * @param[out] o_out if non-NULL put here a pointer to the AVOption
  165. * found
  166. * @param alloc when 1 then the old value will be av_freed() and the
  167. * new av_strduped()
  168. * when 0 then no av_free() nor av_strdup() will be used
  169. * @return 0 if the value has been set, or an AVERROR code in case of
  170. * error:
  171. * AVERROR(ENOENT) if no matching option exists
  172. * AVERROR(ERANGE) if the value is out of range
  173. * AVERROR(EINVAL) if the value is not valid
  174. */
  175. int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
  176. const AVOption *av_set_double(void *obj, const char *name, double n);
  177. const AVOption *av_set_q(void *obj, const char *name, AVRational n);
  178. const AVOption *av_set_int(void *obj, const char *name, int64_t n);
  179. double av_get_double(void *obj, const char *name, const AVOption **o_out);
  180. AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
  181. int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
  182. const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
  183. const AVOption *av_next_option(void *obj, const AVOption *last);
  184. int av_opt_show(void *obj, void *av_log_obj);
  185. void av_opt_set_defaults(void *s);
  186. void av_opt_set_defaults2(void *s, int mask, int flags);
  187. #endif /* AVCODEC_OPT_H */