2134
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1 /*
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2 * AVOptions
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3 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
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4 *
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5 * This file is part of FFmpeg.
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6 *
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7 * FFmpeg is free software; you can redistribute it and/or
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8 * modify it under the terms of the GNU Lesser General Public
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9 * License as published by the Free Software Foundation; either
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10 * version 2.1 of the License, or (at your option) any later version.
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11 *
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12 * FFmpeg is distributed in the hope that it will be useful,
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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15 * Lesser General Public License for more details.
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16 *
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17 * You should have received a copy of the GNU Lesser General Public
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18 * License along with FFmpeg; if not, write to the Free Software
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19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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20 */
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21
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22 #ifndef AVUTIL_OPT_H
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23 #define AVUTIL_OPT_H
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24
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25 /**
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26 * @file
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27 * AVOptions
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28 */
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29
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30 #include "rational.h"
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31 #include "avutil.h"
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32 #include "dict.h"
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33 #include "log.h"
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34 #include "pixfmt.h"
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35 #include "samplefmt.h"
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36
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37 /**
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38 * @defgroup avoptions AVOptions
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39 * @ingroup lavu_data
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40 * @{
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41 * AVOptions provide a generic system to declare options on arbitrary structs
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42 * ("objects"). An option can have a help text, a type and a range of possible
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43 * values. Options may then be enumerated, read and written to.
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44 *
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45 * @section avoptions_implement Implementing AVOptions
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46 * This section describes how to add AVOptions capabilities to a struct.
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47 *
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48 * All AVOptions-related information is stored in an AVClass. Therefore
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49 * the first member of the struct should be a pointer to an AVClass describing it.
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50 * The option field of the AVClass must be set to a NULL-terminated static array
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51 * of AVOptions. Each AVOption must have a non-empty name, a type, a default
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52 * value and for number-type AVOptions also a range of allowed values. It must
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53 * also declare an offset in bytes from the start of the struct, where the field
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54 * associated with this AVOption is located. Other fields in the AVOption struct
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55 * should also be set when applicable, but are not required.
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56 *
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57 * The following example illustrates an AVOptions-enabled struct:
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58 * @code
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59 * typedef struct test_struct {
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60 * AVClass *class;
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61 * int int_opt;
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62 * char *str_opt;
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63 * uint8_t *bin_opt;
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64 * int bin_len;
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65 * } test_struct;
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66 *
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67 * static const AVOption options[] = {
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68 * { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt),
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69 * AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX },
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70 * { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt),
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71 * AV_OPT_TYPE_STRING },
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72 * { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt),
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73 * AV_OPT_TYPE_BINARY },
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74 * { NULL },
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75 * };
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76 *
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77 * static const AVClass test_class = {
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78 * .class_name = "test class",
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79 * .item_name = av_default_item_name,
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80 * .option = options,
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81 * .version = LIBAVUTIL_VERSION_INT,
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82 * };
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83 * @endcode
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84 *
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85 * Next, when allocating your struct, you must ensure that the AVClass pointer
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86 * is set to the correct value. Then, av_opt_set_defaults() can be called to
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87 * initialize defaults. After that the struct is ready to be used with the
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88 * AVOptions API.
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89 *
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90 * When cleaning up, you may use the av_opt_free() function to automatically
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91 * free all the allocated string and binary options.
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92 *
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93 * Continuing with the above example:
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94 *
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95 * @code
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96 * test_struct *alloc_test_struct(void)
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97 * {
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98 * test_struct *ret = av_malloc(sizeof(*ret));
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99 * ret->class = &test_class;
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100 * av_opt_set_defaults(ret);
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101 * return ret;
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102 * }
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103 * void free_test_struct(test_struct **foo)
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104 * {
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105 * av_opt_free(*foo);
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106 * av_freep(foo);
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107 * }
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108 * @endcode
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109 *
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110 * @subsection avoptions_implement_nesting Nesting
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111 * It may happen that an AVOptions-enabled struct contains another
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112 * AVOptions-enabled struct as a member (e.g. AVCodecContext in
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113 * libavcodec exports generic options, while its priv_data field exports
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114 * codec-specific options). In such a case, it is possible to set up the
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115 * parent struct to export a child's options. To do that, simply
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116 * implement AVClass.child_next() and AVClass.child_class_next() in the
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117 * parent struct's AVClass.
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118 * Assuming that the test_struct from above now also contains a
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119 * child_struct field:
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120 *
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121 * @code
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122 * typedef struct child_struct {
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123 * AVClass *class;
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124 * int flags_opt;
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125 * } child_struct;
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126 * static const AVOption child_opts[] = {
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127 * { "test_flags", "This is a test option of flags type.",
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128 * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX },
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129 * { NULL },
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130 * };
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131 * static const AVClass child_class = {
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132 * .class_name = "child class",
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133 * .item_name = av_default_item_name,
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134 * .option = child_opts,
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135 * .version = LIBAVUTIL_VERSION_INT,
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136 * };
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137 *
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138 * void *child_next(void *obj, void *prev)
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139 * {
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140 * test_struct *t = obj;
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141 * if (!prev && t->child_struct)
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142 * return t->child_struct;
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143 * return NULL
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144 * }
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145 * const AVClass child_class_next(const AVClass *prev)
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146 * {
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147 * return prev ? NULL : &child_class;
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148 * }
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149 * @endcode
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150 * Putting child_next() and child_class_next() as defined above into
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151 * test_class will now make child_struct's options accessible through
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152 * test_struct (again, proper setup as described above needs to be done on
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153 * child_struct right after it is created).
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154 *
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155 * From the above example it might not be clear why both child_next()
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156 * and child_class_next() are needed. The distinction is that child_next()
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157 * iterates over actually existing objects, while child_class_next()
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158 * iterates over all possible child classes. E.g. if an AVCodecContext
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159 * was initialized to use a codec which has private options, then its
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160 * child_next() will return AVCodecContext.priv_data and finish
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161 * iterating. OTOH child_class_next() on AVCodecContext.av_class will
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162 * iterate over all available codecs with private options.
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163 *
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164 * @subsection avoptions_implement_named_constants Named constants
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165 * It is possible to create named constants for options. Simply set the unit
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166 * field of the option the constants should apply to to a string and
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167 * create the constants themselves as options of type AV_OPT_TYPE_CONST
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168 * with their unit field set to the same string.
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169 * Their default_val field should contain the value of the named
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170 * constant.
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171 * For example, to add some named constants for the test_flags option
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172 * above, put the following into the child_opts array:
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173 * @code
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174 * { "test_flags", "This is a test option of flags type.",
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175 * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" },
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176 * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" },
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177 * @endcode
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178 *
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179 * @section avoptions_use Using AVOptions
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180 * This section deals with accessing options in an AVOptions-enabled struct.
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181 * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or
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182 * AVFormatContext in libavformat.
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183 *
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184 * @subsection avoptions_use_examine Examining AVOptions
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185 * The basic functions for examining options are av_opt_next(), which iterates
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186 * over all options defined for one object, and av_opt_find(), which searches
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187 * for an option with the given name.
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188 *
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189 * The situation is more complicated with nesting. An AVOptions-enabled struct
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190 * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag
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191 * to av_opt_find() will make the function search children recursively.
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192 *
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193 * For enumerating there are basically two cases. The first is when you want to
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194 * get all options that may potentially exist on the struct and its children
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195 * (e.g. when constructing documentation). In that case you should call
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196 * av_opt_child_class_next() recursively on the parent struct's AVClass. The
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197 * second case is when you have an already initialized struct with all its
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198 * children and you want to get all options that can be actually written or read
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199 * from it. In that case you should call av_opt_child_next() recursively (and
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200 * av_opt_next() on each result).
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201 *
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202 * @subsection avoptions_use_get_set Reading and writing AVOptions
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203 * When setting options, you often have a string read directly from the
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204 * user. In such a case, simply passing it to av_opt_set() is enough. For
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205 * non-string type options, av_opt_set() will parse the string according to the
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206 * option type.
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207 *
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208 * Similarly av_opt_get() will read any option type and convert it to a string
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209 * which will be returned. Do not forget that the string is allocated, so you
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210 * have to free it with av_free().
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211 *
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212 * In some cases it may be more convenient to put all options into an
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213 * AVDictionary and call av_opt_set_dict() on it. A specific case of this
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214 * are the format/codec open functions in lavf/lavc which take a dictionary
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215 * filled with option as a parameter. This allows to set some options
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216 * that cannot be set otherwise, since e.g. the input file format is not known
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217 * before the file is actually opened.
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218 */
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219
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220 enum AVOptionType{
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221 AV_OPT_TYPE_FLAGS,
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222 AV_OPT_TYPE_INT,
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223 AV_OPT_TYPE_INT64,
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224 AV_OPT_TYPE_DOUBLE,
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225 AV_OPT_TYPE_FLOAT,
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226 AV_OPT_TYPE_STRING,
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227 AV_OPT_TYPE_RATIONAL,
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228 AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
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229 AV_OPT_TYPE_CONST = 128,
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230 AV_OPT_TYPE_IMAGE_SIZE = MKBETAG('S','I','Z','E'), ///< offset must point to two consecutive integers
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231 AV_OPT_TYPE_PIXEL_FMT = MKBETAG('P','F','M','T'),
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232 AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'),
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233 AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational
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234 AV_OPT_TYPE_DURATION = MKBETAG('D','U','R',' '),
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235 AV_OPT_TYPE_COLOR = MKBETAG('C','O','L','R'),
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236 #if FF_API_OLD_AVOPTIONS
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237 FF_OPT_TYPE_FLAGS = 0,
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238 FF_OPT_TYPE_INT,
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239 FF_OPT_TYPE_INT64,
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240 FF_OPT_TYPE_DOUBLE,
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241 FF_OPT_TYPE_FLOAT,
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242 FF_OPT_TYPE_STRING,
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243 FF_OPT_TYPE_RATIONAL,
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244 FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length
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245 FF_OPT_TYPE_CONST=128,
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246 #endif
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247 };
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248
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249 /**
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250 * AVOption
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251 */
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252 typedef struct AVOption {
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253 const char *name;
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254
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255 /**
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256 * short English help text
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257 * @todo What about other languages?
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258 */
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259 const char *help;
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260
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261 /**
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262 * The offset relative to the context structure where the option
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263 * value is stored. It should be 0 for named constants.
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264 */
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265 int offset;
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266 enum AVOptionType type;
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267
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268 /**
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269 * the default value for scalar options
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270 */
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271 union {
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272 int64_t i64;
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273 double dbl;
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274 const char *str;
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275 /* TODO those are unused now */
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276 AVRational q;
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277 } default_val;
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278 double min; ///< minimum valid value for the option
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279 double max; ///< maximum valid value for the option
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280
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281 int flags;
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282 #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding
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283 #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding
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284 #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ...
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285 #define AV_OPT_FLAG_AUDIO_PARAM 8
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286 #define AV_OPT_FLAG_VIDEO_PARAM 16
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287 #define AV_OPT_FLAG_SUBTITLE_PARAM 32
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288 #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
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289 //FIXME think about enc-audio, ... style flags
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290
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291 /**
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292 * The logical unit to which the option belongs. Non-constant
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293 * options and corresponding named constants share the same
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294 * unit. May be NULL.
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295 */
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296 const char *unit;
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297 } AVOption;
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298
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299 /**
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300 * A single allowed range of values, or a single allowed value.
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301 */
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302 typedef struct AVOptionRange {
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303 const char *str;
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304 double value_min, value_max; ///< For string ranges this represents the min/max length, for dimensions this represents the min/max pixel count
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305 double component_min, component_max; ///< For string this represents the unicode range for chars, 0-127 limits to ASCII
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306 int is_range; ///< if set to 1 the struct encodes a range, if set to 0 a single value
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307 } AVOptionRange;
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308
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309 /**
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310 * List of AVOptionRange structs
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311 */
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312 typedef struct AVOptionRanges {
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313 AVOptionRange **range;
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314 int nb_ranges;
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315 } AVOptionRanges;
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316
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317
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318 #if FF_API_FIND_OPT
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319 /**
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320 * Look for an option in obj. Look only for the options which
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321 * have the flags set as specified in mask and flags (that is,
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322 * for which it is the case that opt->flags & mask == flags).
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323 *
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324 * @param[in] obj a pointer to a struct whose first element is a
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325 * pointer to an AVClass
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326 * @param[in] name the name of the option to look for
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327 * @param[in] unit the unit of the option to look for, or any if NULL
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328 * @return a pointer to the option found, or NULL if no option
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329 * has been found
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330 *
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331 * @deprecated use av_opt_find.
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332 */
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333 attribute_deprecated
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334 const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags);
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335 #endif
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336
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337 #if FF_API_OLD_AVOPTIONS
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338 /**
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339 * Set the field of obj with the given name to value.
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340 *
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341 * @param[in] obj A struct whose first element is a pointer to an
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342 * AVClass.
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343 * @param[in] name the name of the field to set
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344 * @param[in] val The value to set. If the field is not of a string
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345 * type, then the given string is parsed.
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346 * SI postfixes and some named scalars are supported.
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347 * If the field is of a numeric type, it has to be a numeric or named
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348 * scalar. Behavior with more than one scalar and +- infix operators
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349 * is undefined.
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350 * If the field is of a flags type, it has to be a sequence of numeric
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351 * scalars or named flags separated by '+' or '-'. Prefixing a flag
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352 * with '+' causes it to be set without affecting the other flags;
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353 * similarly, '-' unsets a flag.
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354 * @param[out] o_out if non-NULL put here a pointer to the AVOption
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355 * found
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356 * @param alloc this parameter is currently ignored
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357 * @return 0 if the value has been set, or an AVERROR code in case of
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358 * error:
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359 * AVERROR_OPTION_NOT_FOUND if no matching option exists
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360 * AVERROR(ERANGE) if the value is out of range
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361 * AVERROR(EINVAL) if the value is not valid
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362 * @deprecated use av_opt_set()
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363 */
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364 attribute_deprecated
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365 int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out);
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366
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367 attribute_deprecated const AVOption *av_set_double(void *obj, const char *name, double n);
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368 attribute_deprecated const AVOption *av_set_q(void *obj, const char *name, AVRational n);
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369 attribute_deprecated const AVOption *av_set_int(void *obj, const char *name, int64_t n);
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370
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371 double av_get_double(void *obj, const char *name, const AVOption **o_out);
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372 AVRational av_get_q(void *obj, const char *name, const AVOption **o_out);
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373 int64_t av_get_int(void *obj, const char *name, const AVOption **o_out);
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374 attribute_deprecated const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len);
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375 attribute_deprecated const AVOption *av_next_option(void *obj, const AVOption *last);
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376 #endif
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377
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378 /**
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379 * Show the obj options.
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380 *
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381 * @param req_flags requested flags for the options to show. Show only the
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382 * options for which it is opt->flags & req_flags.
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383 * @param rej_flags rejected flags for the options to show. Show only the
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384 * options for which it is !(opt->flags & req_flags).
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385 * @param av_log_obj log context to use for showing the options
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386 */
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387 int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
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388
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389 /**
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390 * Set the values of all AVOption fields to their default values.
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391 *
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392 * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass)
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393 */
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394 void av_opt_set_defaults(void *s);
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395
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396 #if FF_API_OLD_AVOPTIONS
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397 attribute_deprecated
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398 void av_opt_set_defaults2(void *s, int mask, int flags);
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399 #endif
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400
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401 /**
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402 * Parse the key/value pairs list in opts. For each key/value pair
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403 * found, stores the value in the field in ctx that is named like the
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404 * key. ctx must be an AVClass context, storing is done using
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405 * AVOptions.
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406 *
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407 * @param opts options string to parse, may be NULL
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408 * @param key_val_sep a 0-terminated list of characters used to
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409 * separate key from value
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410 * @param pairs_sep a 0-terminated list of characters used to separate
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411 * two pairs from each other
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412 * @return the number of successfully set key/value pairs, or a negative
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413 * value corresponding to an AVERROR code in case of error:
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414 * AVERROR(EINVAL) if opts cannot be parsed,
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415 * the error code issued by av_set_string3() if a key/value pair
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416 * cannot be set
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417 */
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418 int av_set_options_string(void *ctx, const char *opts,
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419 const char *key_val_sep, const char *pairs_sep);
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420
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421 /**
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422 * Parse the key-value pairs list in opts. For each key=value pair found,
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423 * set the value of the corresponding option in ctx.
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424 *
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425 * @param ctx the AVClass object to set options on
|
|
426 * @param opts the options string, key-value pairs separated by a
|
|
427 * delimiter
|
|
428 * @param shorthand a NULL-terminated array of options names for shorthand
|
|
429 * notation: if the first field in opts has no key part,
|
|
430 * the key is taken from the first element of shorthand;
|
|
431 * then again for the second, etc., until either opts is
|
|
432 * finished, shorthand is finished or a named option is
|
|
433 * found; after that, all options must be named
|
|
434 * @param key_val_sep a 0-terminated list of characters used to separate
|
|
435 * key from value, for example '='
|
|
436 * @param pairs_sep a 0-terminated list of characters used to separate
|
|
437 * two pairs from each other, for example ':' or ','
|
|
438 * @return the number of successfully set key=value pairs, or a negative
|
|
439 * value corresponding to an AVERROR code in case of error:
|
|
440 * AVERROR(EINVAL) if opts cannot be parsed,
|
|
441 * the error code issued by av_set_string3() if a key/value pair
|
|
442 * cannot be set
|
|
443 *
|
|
444 * Options names must use only the following characters: a-z A-Z 0-9 - . / _
|
|
445 * Separators must use characters distinct from option names and from each
|
|
446 * other.
|
|
447 */
|
|
448 int av_opt_set_from_string(void *ctx, const char *opts,
|
|
449 const char *const *shorthand,
|
|
450 const char *key_val_sep, const char *pairs_sep);
|
|
451 /**
|
|
452 * Free all string and binary options in obj.
|
|
453 */
|
|
454 void av_opt_free(void *obj);
|
|
455
|
|
456 /**
|
|
457 * Check whether a particular flag is set in a flags field.
|
|
458 *
|
|
459 * @param field_name the name of the flag field option
|
|
460 * @param flag_name the name of the flag to check
|
|
461 * @return non-zero if the flag is set, zero if the flag isn't set,
|
|
462 * isn't of the right type, or the flags field doesn't exist.
|
|
463 */
|
|
464 int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name);
|
|
465
|
|
466 /**
|
|
467 * Set all the options from a given dictionary on an object.
|
|
468 *
|
|
469 * @param obj a struct whose first element is a pointer to AVClass
|
|
470 * @param options options to process. This dictionary will be freed and replaced
|
|
471 * by a new one containing all options not found in obj.
|
|
472 * Of course this new dictionary needs to be freed by caller
|
|
473 * with av_dict_free().
|
|
474 *
|
|
475 * @return 0 on success, a negative AVERROR if some option was found in obj,
|
|
476 * but could not be set.
|
|
477 *
|
|
478 * @see av_dict_copy()
|
|
479 */
|
|
480 int av_opt_set_dict(void *obj, struct AVDictionary **options);
|
|
481
|
|
482 /**
|
|
483 * Extract a key-value pair from the beginning of a string.
|
|
484 *
|
|
485 * @param ropts pointer to the options string, will be updated to
|
|
486 * point to the rest of the string (one of the pairs_sep
|
|
487 * or the final NUL)
|
|
488 * @param key_val_sep a 0-terminated list of characters used to separate
|
|
489 * key from value, for example '='
|
|
490 * @param pairs_sep a 0-terminated list of characters used to separate
|
|
491 * two pairs from each other, for example ':' or ','
|
|
492 * @param flags flags; see the AV_OPT_FLAG_* values below
|
|
493 * @param rkey parsed key; must be freed using av_free()
|
|
494 * @param rval parsed value; must be freed using av_free()
|
|
495 *
|
|
496 * @return >=0 for success, or a negative value corresponding to an
|
|
497 * AVERROR code in case of error; in particular:
|
|
498 * AVERROR(EINVAL) if no key is present
|
|
499 *
|
|
500 */
|
|
501 int av_opt_get_key_value(const char **ropts,
|
|
502 const char *key_val_sep, const char *pairs_sep,
|
|
503 unsigned flags,
|
|
504 char **rkey, char **rval);
|
|
505
|
|
506 enum {
|
|
507
|
|
508 /**
|
|
509 * Accept to parse a value without a key; the key will then be returned
|
|
510 * as NULL.
|
|
511 */
|
|
512 AV_OPT_FLAG_IMPLICIT_KEY = 1,
|
|
513 };
|
|
514
|
|
515 /**
|
|
516 * @defgroup opt_eval_funcs Evaluating option strings
|
|
517 * @{
|
|
518 * This group of functions can be used to evaluate option strings
|
|
519 * and get numbers out of them. They do the same thing as av_opt_set(),
|
|
520 * except the result is written into the caller-supplied pointer.
|
|
521 *
|
|
522 * @param obj a struct whose first element is a pointer to AVClass.
|
|
523 * @param o an option for which the string is to be evaluated.
|
|
524 * @param val string to be evaluated.
|
|
525 * @param *_out value of the string will be written here.
|
|
526 *
|
|
527 * @return 0 on success, a negative number on failure.
|
|
528 */
|
|
529 int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out);
|
|
530 int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out);
|
|
531 int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out);
|
|
532 int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out);
|
|
533 int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out);
|
|
534 int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out);
|
|
535 /**
|
|
536 * @}
|
|
537 */
|
|
538
|
|
539 #define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the
|
|
540 given object first. */
|
|
541 /**
|
|
542 * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass
|
|
543 * instead of a required pointer to a struct containing AVClass. This is
|
|
544 * useful for searching for options without needing to allocate the corresponding
|
|
545 * object.
|
|
546 */
|
|
547 #define AV_OPT_SEARCH_FAKE_OBJ 0x0002
|
|
548
|
|
549 /**
|
|
550 * Look for an option in an object. Consider only options which
|
|
551 * have all the specified flags set.
|
|
552 *
|
|
553 * @param[in] obj A pointer to a struct whose first element is a
|
|
554 * pointer to an AVClass.
|
|
555 * Alternatively a double pointer to an AVClass, if
|
|
556 * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
|
|
557 * @param[in] name The name of the option to look for.
|
|
558 * @param[in] unit When searching for named constants, name of the unit
|
|
559 * it belongs to.
|
|
560 * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
|
|
561 * @param search_flags A combination of AV_OPT_SEARCH_*.
|
|
562 *
|
|
563 * @return A pointer to the option found, or NULL if no option
|
|
564 * was found.
|
|
565 *
|
|
566 * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable
|
|
567 * directly with av_set_string3(). Use special calls which take an options
|
|
568 * AVDictionary (e.g. avformat_open_input()) to set options found with this
|
|
569 * flag.
|
|
570 */
|
|
571 const AVOption *av_opt_find(void *obj, const char *name, const char *unit,
|
|
572 int opt_flags, int search_flags);
|
|
573
|
|
574 /**
|
|
575 * Look for an option in an object. Consider only options which
|
|
576 * have all the specified flags set.
|
|
577 *
|
|
578 * @param[in] obj A pointer to a struct whose first element is a
|
|
579 * pointer to an AVClass.
|
|
580 * Alternatively a double pointer to an AVClass, if
|
|
581 * AV_OPT_SEARCH_FAKE_OBJ search flag is set.
|
|
582 * @param[in] name The name of the option to look for.
|
|
583 * @param[in] unit When searching for named constants, name of the unit
|
|
584 * it belongs to.
|
|
585 * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG).
|
|
586 * @param search_flags A combination of AV_OPT_SEARCH_*.
|
|
587 * @param[out] target_obj if non-NULL, an object to which the option belongs will be
|
|
588 * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present
|
|
589 * in search_flags. This parameter is ignored if search_flags contain
|
|
590 * AV_OPT_SEARCH_FAKE_OBJ.
|
|
591 *
|
|
592 * @return A pointer to the option found, or NULL if no option
|
|
593 * was found.
|
|
594 */
|
|
595 const AVOption *av_opt_find2(void *obj, const char *name, const char *unit,
|
|
596 int opt_flags, int search_flags, void **target_obj);
|
|
597
|
|
598 /**
|
|
599 * Iterate over all AVOptions belonging to obj.
|
|
600 *
|
|
601 * @param obj an AVOptions-enabled struct or a double pointer to an
|
|
602 * AVClass describing it.
|
|
603 * @param prev result of the previous call to av_opt_next() on this object
|
|
604 * or NULL
|
|
605 * @return next AVOption or NULL
|
|
606 */
|
|
607 const AVOption *av_opt_next(void *obj, const AVOption *prev);
|
|
608
|
|
609 /**
|
|
610 * Iterate over AVOptions-enabled children of obj.
|
|
611 *
|
|
612 * @param prev result of a previous call to this function or NULL
|
|
613 * @return next AVOptions-enabled child or NULL
|
|
614 */
|
|
615 void *av_opt_child_next(void *obj, void *prev);
|
|
616
|
|
617 /**
|
|
618 * Iterate over potential AVOptions-enabled children of parent.
|
|
619 *
|
|
620 * @param prev result of a previous call to this function or NULL
|
|
621 * @return AVClass corresponding to next potential child or NULL
|
|
622 */
|
|
623 const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev);
|
|
624
|
|
625 /**
|
|
626 * @defgroup opt_set_funcs Option setting functions
|
|
627 * @{
|
|
628 * Those functions set the field of obj with the given name to value.
|
|
629 *
|
|
630 * @param[in] obj A struct whose first element is a pointer to an AVClass.
|
|
631 * @param[in] name the name of the field to set
|
|
632 * @param[in] val The value to set. In case of av_opt_set() if the field is not
|
|
633 * of a string type, then the given string is parsed.
|
|
634 * SI postfixes and some named scalars are supported.
|
|
635 * If the field is of a numeric type, it has to be a numeric or named
|
|
636 * scalar. Behavior with more than one scalar and +- infix operators
|
|
637 * is undefined.
|
|
638 * If the field is of a flags type, it has to be a sequence of numeric
|
|
639 * scalars or named flags separated by '+' or '-'. Prefixing a flag
|
|
640 * with '+' causes it to be set without affecting the other flags;
|
|
641 * similarly, '-' unsets a flag.
|
|
642 * @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
|
|
643 * is passed here, then the option may be set on a child of obj.
|
|
644 *
|
|
645 * @return 0 if the value has been set, or an AVERROR code in case of
|
|
646 * error:
|
|
647 * AVERROR_OPTION_NOT_FOUND if no matching option exists
|
|
648 * AVERROR(ERANGE) if the value is out of range
|
|
649 * AVERROR(EINVAL) if the value is not valid
|
|
650 */
|
|
651 int av_opt_set (void *obj, const char *name, const char *val, int search_flags);
|
|
652 int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags);
|
|
653 int av_opt_set_double(void *obj, const char *name, double val, int search_flags);
|
|
654 int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags);
|
|
655 int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags);
|
|
656 int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags);
|
|
657 int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags);
|
|
658 int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags);
|
|
659 int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags);
|
|
660
|
|
661 /**
|
|
662 * Set a binary option to an integer list.
|
|
663 *
|
|
664 * @param obj AVClass object to set options on
|
|
665 * @param name name of the binary option
|
|
666 * @param val pointer to an integer list (must have the correct type with
|
|
667 * regard to the contents of the list)
|
|
668 * @param term list terminator (usually 0 or -1)
|
|
669 * @param flags search flags
|
|
670 */
|
|
671 #define av_opt_set_int_list(obj, name, val, term, flags) \
|
|
672 (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \
|
|
673 AVERROR(EINVAL) : \
|
|
674 av_opt_set_bin(obj, name, (const uint8_t *)(val), \
|
|
675 av_int_list_length(val, term) * sizeof(*(val)), flags))
|
|
676 /**
|
|
677 * @}
|
|
678 */
|
|
679
|
|
680 /**
|
|
681 * @defgroup opt_get_funcs Option getting functions
|
|
682 * @{
|
|
683 * Those functions get a value of the option with the given name from an object.
|
|
684 *
|
|
685 * @param[in] obj a struct whose first element is a pointer to an AVClass.
|
|
686 * @param[in] name name of the option to get.
|
|
687 * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN
|
|
688 * is passed here, then the option may be found in a child of obj.
|
|
689 * @param[out] out_val value of the option will be written here
|
|
690 * @return 0 on success, a negative error code otherwise
|
|
691 */
|
|
692 /**
|
|
693 * @note the returned string will av_malloc()ed and must be av_free()ed by the caller
|
|
694 */
|
|
695 int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val);
|
|
696 int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val);
|
|
697 int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val);
|
|
698 int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val);
|
|
699 int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out);
|
|
700 int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt);
|
|
701 int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt);
|
|
702 int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val);
|
|
703 /**
|
|
704 * @}
|
|
705 */
|
|
706 /**
|
|
707 * Gets a pointer to the requested field in a struct.
|
|
708 * This function allows accessing a struct even when its fields are moved or
|
|
709 * renamed since the application making the access has been compiled,
|
|
710 *
|
|
711 * @returns a pointer to the field, it can be cast to the correct type and read
|
|
712 * or written to.
|
|
713 */
|
|
714 void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name);
|
|
715
|
|
716 /**
|
|
717 * Free an AVOptionRanges struct and set it to NULL.
|
|
718 */
|
|
719 void av_opt_freep_ranges(AVOptionRanges **ranges);
|
|
720
|
|
721 /**
|
|
722 * Get a list of allowed ranges for the given option.
|
|
723 *
|
|
724 * The returned list may depend on other fields in obj like for example profile.
|
|
725 *
|
|
726 * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
|
|
727 * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
|
|
728 *
|
|
729 * The result must be freed with av_opt_freep_ranges.
|
|
730 *
|
|
731 * @return >= 0 on success, a negative errro code otherwise
|
|
732 */
|
|
733 int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags);
|
|
734
|
|
735 /**
|
|
736 * Get a default list of allowed ranges for the given option.
|
|
737 *
|
|
738 * This list is constructed without using the AVClass.query_ranges() callback
|
|
739 * and can be used as fallback from within the callback.
|
|
740 *
|
|
741 * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored
|
|
742 * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance
|
|
743 *
|
|
744 * The result must be freed with av_opt_free_ranges.
|
|
745 *
|
|
746 * @return >= 0 on success, a negative errro code otherwise
|
|
747 */
|
|
748 int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags);
|
|
749
|
|
750 /**
|
|
751 * @}
|
|
752 */
|
|
753
|
|
754 #endif /* AVUTIL_OPT_H */
|