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4349 | Serge | 1 | /* |
2 | * AVOptions |
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3 | * copyright (c) 2005 Michael Niedermayer |
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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 | |||
22 | #ifndef AVUTIL_OPT_H |
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23 | #define AVUTIL_OPT_H |
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24 | |||
25 | /** |
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26 | * @file |
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27 | * AVOptions |
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28 | */ |
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29 | |||
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 | |||
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 test_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 = test_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 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 | |||
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 | AV_OPT_TYPE_CHANNEL_LAYOUT = MKBETAG('C','H','L','A'), |
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237 | #if FF_API_OLD_AVOPTIONS |
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238 | FF_OPT_TYPE_FLAGS = 0, |
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239 | FF_OPT_TYPE_INT, |
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240 | FF_OPT_TYPE_INT64, |
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241 | FF_OPT_TYPE_DOUBLE, |
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242 | FF_OPT_TYPE_FLOAT, |
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243 | FF_OPT_TYPE_STRING, |
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244 | FF_OPT_TYPE_RATIONAL, |
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245 | FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length |
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246 | FF_OPT_TYPE_CONST=128, |
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247 | #endif |
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248 | }; |
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249 | |||
250 | /** |
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251 | * AVOption |
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252 | */ |
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253 | typedef struct AVOption { |
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254 | const char *name; |
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255 | |||
256 | /** |
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257 | * short English help text |
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258 | * @todo What about other languages? |
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259 | */ |
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260 | const char *help; |
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261 | |||
262 | /** |
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263 | * The offset relative to the context structure where the option |
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264 | * value is stored. It should be 0 for named constants. |
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265 | */ |
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266 | int offset; |
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267 | enum AVOptionType type; |
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268 | |||
269 | /** |
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270 | * the default value for scalar options |
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271 | */ |
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272 | union { |
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273 | int64_t i64; |
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274 | double dbl; |
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275 | const char *str; |
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276 | /* TODO those are unused now */ |
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277 | AVRational q; |
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278 | } default_val; |
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279 | double min; ///< minimum valid value for the option |
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280 | double max; ///< maximum valid value for the option |
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281 | |||
282 | int flags; |
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283 | #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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284 | #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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285 | #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ... |
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286 | #define AV_OPT_FLAG_AUDIO_PARAM 8 |
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287 | #define AV_OPT_FLAG_VIDEO_PARAM 16 |
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288 | #define AV_OPT_FLAG_SUBTITLE_PARAM 32 |
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289 | #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering |
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290 | //FIXME think about enc-audio, ... style flags |
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291 | |||
292 | /** |
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293 | * The logical unit to which the option belongs. Non-constant |
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294 | * options and corresponding named constants share the same |
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295 | * unit. May be NULL. |
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296 | */ |
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297 | const char *unit; |
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298 | } AVOption; |
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299 | |||
300 | /** |
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301 | * A single allowed range of values, or a single allowed value. |
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302 | */ |
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303 | typedef struct AVOptionRange { |
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304 | const char *str; |
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305 | 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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306 | double component_min, component_max; ///< For string this represents the unicode range for chars, 0-127 limits to ASCII |
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307 | int is_range; ///< if set to 1 the struct encodes a range, if set to 0 a single value |
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308 | } AVOptionRange; |
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309 | |||
310 | /** |
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311 | * List of AVOptionRange structs |
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312 | */ |
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313 | typedef struct AVOptionRanges { |
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314 | AVOptionRange **range; |
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315 | int nb_ranges; |
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316 | } AVOptionRanges; |
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317 | |||
318 | |||
319 | #if FF_API_FIND_OPT |
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320 | /** |
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321 | * Look for an option in obj. Look only for the options which |
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322 | * have the flags set as specified in mask and flags (that is, |
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323 | * for which it is the case that (opt->flags & mask) == flags). |
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324 | * |
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325 | * @param[in] obj a pointer to a struct whose first element is a |
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326 | * pointer to an AVClass |
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327 | * @param[in] name the name of the option to look for |
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328 | * @param[in] unit the unit of the option to look for, or any if NULL |
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329 | * @return a pointer to the option found, or NULL if no option |
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330 | * has been found |
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331 | * |
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332 | * @deprecated use av_opt_find. |
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333 | */ |
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334 | attribute_deprecated |
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335 | const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags); |
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336 | #endif |
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337 | |||
338 | #if FF_API_OLD_AVOPTIONS |
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339 | /** |
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340 | * Set the field of obj with the given name to value. |
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341 | * |
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342 | * @param[in] obj A struct whose first element is a pointer to an |
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343 | * AVClass. |
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344 | * @param[in] name the name of the field to set |
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345 | * @param[in] val The value to set. If the field is not of a string |
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346 | * type, then the given string is parsed. |
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347 | * SI postfixes and some named scalars are supported. |
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348 | * If the field is of a numeric type, it has to be a numeric or named |
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349 | * scalar. Behavior with more than one scalar and +- infix operators |
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350 | * is undefined. |
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351 | * If the field is of a flags type, it has to be a sequence of numeric |
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352 | * scalars or named flags separated by '+' or '-'. Prefixing a flag |
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353 | * with '+' causes it to be set without affecting the other flags; |
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354 | * similarly, '-' unsets a flag. |
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355 | * @param[out] o_out if non-NULL put here a pointer to the AVOption |
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356 | * found |
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357 | * @param alloc this parameter is currently ignored |
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358 | * @return 0 if the value has been set, or an AVERROR code in case of |
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359 | * error: |
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360 | * AVERROR_OPTION_NOT_FOUND if no matching option exists |
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361 | * AVERROR(ERANGE) if the value is out of range |
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362 | * AVERROR(EINVAL) if the value is not valid |
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363 | * @deprecated use av_opt_set() |
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364 | */ |
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365 | attribute_deprecated |
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366 | int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out); |
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367 | |||
368 | attribute_deprecated const AVOption *av_set_double(void *obj, const char *name, double n); |
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369 | attribute_deprecated const AVOption *av_set_q(void *obj, const char *name, AVRational n); |
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370 | attribute_deprecated const AVOption *av_set_int(void *obj, const char *name, int64_t n); |
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371 | |||
372 | double av_get_double(void *obj, const char *name, const AVOption **o_out); |
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373 | AVRational av_get_q(void *obj, const char *name, const AVOption **o_out); |
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374 | int64_t av_get_int(void *obj, const char *name, const AVOption **o_out); |
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375 | 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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376 | attribute_deprecated const AVOption *av_next_option(void *obj, const AVOption *last); |
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377 | #endif |
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378 | |||
379 | /** |
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380 | * Show the obj options. |
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381 | * |
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382 | * @param req_flags requested flags for the options to show. Show only the |
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383 | * options for which it is opt->flags & req_flags. |
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384 | * @param rej_flags rejected flags for the options to show. Show only the |
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385 | * options for which it is !(opt->flags & req_flags). |
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386 | * @param av_log_obj log context to use for showing the options |
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387 | */ |
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388 | int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags); |
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389 | |||
390 | /** |
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391 | * Set the values of all AVOption fields to their default values. |
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392 | * |
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393 | * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass) |
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394 | */ |
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395 | void av_opt_set_defaults(void *s); |
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396 | |||
397 | #if FF_API_OLD_AVOPTIONS |
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398 | attribute_deprecated |
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399 | void av_opt_set_defaults2(void *s, int mask, int flags); |
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400 | #endif |
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401 | |||
402 | /** |
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403 | * Parse the key/value pairs list in opts. For each key/value pair |
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404 | * found, stores the value in the field in ctx that is named like the |
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405 | * key. ctx must be an AVClass context, storing is done using |
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406 | * AVOptions. |
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407 | * |
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408 | * @param opts options string to parse, may be NULL |
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409 | * @param key_val_sep a 0-terminated list of characters used to |
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410 | * separate key from value |
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411 | * @param pairs_sep a 0-terminated list of characters used to separate |
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412 | * two pairs from each other |
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413 | * @return the number of successfully set key/value pairs, or a negative |
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414 | * value corresponding to an AVERROR code in case of error: |
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415 | * AVERROR(EINVAL) if opts cannot be parsed, |
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416 | * the error code issued by av_set_string3() if a key/value pair |
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417 | * cannot be set |
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418 | */ |
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419 | int av_set_options_string(void *ctx, const char *opts, |
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420 | const char *key_val_sep, const char *pairs_sep); |
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421 | |||
422 | /** |
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423 | * Parse the key-value pairs list in opts. For each key=value pair found, |
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424 | * set the value of the corresponding option in ctx. |
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425 | * |
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426 | * @param ctx the AVClass object to set options on |
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427 | * @param opts the options string, key-value pairs separated by a |
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428 | * delimiter |
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429 | * @param shorthand a NULL-terminated array of options names for shorthand |
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430 | * notation: if the first field in opts has no key part, |
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431 | * the key is taken from the first element of shorthand; |
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432 | * then again for the second, etc., until either opts is |
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433 | * finished, shorthand is finished or a named option is |
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434 | * found; after that, all options must be named |
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435 | * @param key_val_sep a 0-terminated list of characters used to separate |
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436 | * key from value, for example '=' |
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437 | * @param pairs_sep a 0-terminated list of characters used to separate |
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438 | * two pairs from each other, for example ':' or ',' |
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439 | * @return the number of successfully set key=value pairs, or a negative |
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440 | * value corresponding to an AVERROR code in case of error: |
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441 | * AVERROR(EINVAL) if opts cannot be parsed, |
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442 | * the error code issued by av_set_string3() if a key/value pair |
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443 | * cannot be set |
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444 | * |
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445 | * Options names must use only the following characters: a-z A-Z 0-9 - . / _ |
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446 | * Separators must use characters distinct from option names and from each |
||
447 | * other. |
||
448 | */ |
||
449 | int av_opt_set_from_string(void *ctx, const char *opts, |
||
450 | const char *const *shorthand, |
||
451 | const char *key_val_sep, const char *pairs_sep); |
||
452 | /** |
||
453 | * Free all string and binary options in obj. |
||
454 | */ |
||
455 | void av_opt_free(void *obj); |
||
456 | |||
457 | /** |
||
458 | * Check whether a particular flag is set in a flags field. |
||
459 | * |
||
460 | * @param field_name the name of the flag field option |
||
461 | * @param flag_name the name of the flag to check |
||
462 | * @return non-zero if the flag is set, zero if the flag isn't set, |
||
463 | * isn't of the right type, or the flags field doesn't exist. |
||
464 | */ |
||
465 | int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name); |
||
466 | |||
467 | /** |
||
468 | * Set all the options from a given dictionary on an object. |
||
469 | * |
||
470 | * @param obj a struct whose first element is a pointer to AVClass |
||
471 | * @param options options to process. This dictionary will be freed and replaced |
||
472 | * by a new one containing all options not found in obj. |
||
473 | * Of course this new dictionary needs to be freed by caller |
||
474 | * with av_dict_free(). |
||
475 | * |
||
476 | * @return 0 on success, a negative AVERROR if some option was found in obj, |
||
477 | * but could not be set. |
||
478 | * |
||
479 | * @see av_dict_copy() |
||
480 | */ |
||
481 | int av_opt_set_dict(void *obj, struct AVDictionary **options); |
||
482 | |||
483 | /** |
||
484 | * Extract a key-value pair from the beginning of a string. |
||
485 | * |
||
486 | * @param ropts pointer to the options string, will be updated to |
||
487 | * point to the rest of the string (one of the pairs_sep |
||
488 | * or the final NUL) |
||
489 | * @param key_val_sep a 0-terminated list of characters used to separate |
||
490 | * key from value, for example '=' |
||
491 | * @param pairs_sep a 0-terminated list of characters used to separate |
||
492 | * two pairs from each other, for example ':' or ',' |
||
493 | * @param flags flags; see the AV_OPT_FLAG_* values below |
||
494 | * @param rkey parsed key; must be freed using av_free() |
||
495 | * @param rval parsed value; must be freed using av_free() |
||
496 | * |
||
497 | * @return >=0 for success, or a negative value corresponding to an |
||
498 | * AVERROR code in case of error; in particular: |
||
499 | * AVERROR(EINVAL) if no key is present |
||
500 | * |
||
501 | */ |
||
502 | int av_opt_get_key_value(const char **ropts, |
||
503 | const char *key_val_sep, const char *pairs_sep, |
||
504 | unsigned flags, |
||
505 | char **rkey, char **rval); |
||
506 | |||
507 | enum { |
||
508 | |||
509 | /** |
||
510 | * Accept to parse a value without a key; the key will then be returned |
||
511 | * as NULL. |
||
512 | */ |
||
513 | AV_OPT_FLAG_IMPLICIT_KEY = 1, |
||
514 | }; |
||
515 | |||
516 | /** |
||
517 | * @defgroup opt_eval_funcs Evaluating option strings |
||
518 | * @{ |
||
519 | * This group of functions can be used to evaluate option strings |
||
520 | * and get numbers out of them. They do the same thing as av_opt_set(), |
||
521 | * except the result is written into the caller-supplied pointer. |
||
522 | * |
||
523 | * @param obj a struct whose first element is a pointer to AVClass. |
||
524 | * @param o an option for which the string is to be evaluated. |
||
525 | * @param val string to be evaluated. |
||
526 | * @param *_out value of the string will be written here. |
||
527 | * |
||
528 | * @return 0 on success, a negative number on failure. |
||
529 | */ |
||
530 | int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out); |
||
531 | int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out); |
||
532 | int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out); |
||
533 | int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out); |
||
534 | int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out); |
||
535 | int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out); |
||
536 | /** |
||
537 | * @} |
||
538 | */ |
||
539 | |||
540 | #define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the |
||
541 | given object first. */ |
||
542 | /** |
||
543 | * The obj passed to av_opt_find() is fake -- only a double pointer to AVClass |
||
544 | * instead of a required pointer to a struct containing AVClass. This is |
||
545 | * useful for searching for options without needing to allocate the corresponding |
||
546 | * object. |
||
547 | */ |
||
548 | #define AV_OPT_SEARCH_FAKE_OBJ 0x0002 |
||
549 | |||
550 | /** |
||
551 | * Look for an option in an object. Consider only options which |
||
552 | * have all the specified flags set. |
||
553 | * |
||
554 | * @param[in] obj A pointer to a struct whose first element is a |
||
555 | * pointer to an AVClass. |
||
556 | * Alternatively a double pointer to an AVClass, if |
||
557 | * AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
||
558 | * @param[in] name The name of the option to look for. |
||
559 | * @param[in] unit When searching for named constants, name of the unit |
||
560 | * it belongs to. |
||
561 | * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
||
562 | * @param search_flags A combination of AV_OPT_SEARCH_*. |
||
563 | * |
||
564 | * @return A pointer to the option found, or NULL if no option |
||
565 | * was found. |
||
566 | * |
||
567 | * @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable |
||
568 | * directly with av_set_string3(). Use special calls which take an options |
||
569 | * AVDictionary (e.g. avformat_open_input()) to set options found with this |
||
570 | * flag. |
||
571 | */ |
||
572 | const AVOption *av_opt_find(void *obj, const char *name, const char *unit, |
||
573 | int opt_flags, int search_flags); |
||
574 | |||
575 | /** |
||
576 | * Look for an option in an object. Consider only options which |
||
577 | * have all the specified flags set. |
||
578 | * |
||
579 | * @param[in] obj A pointer to a struct whose first element is a |
||
580 | * pointer to an AVClass. |
||
581 | * Alternatively a double pointer to an AVClass, if |
||
582 | * AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
||
583 | * @param[in] name The name of the option to look for. |
||
584 | * @param[in] unit When searching for named constants, name of the unit |
||
585 | * it belongs to. |
||
586 | * @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
||
587 | * @param search_flags A combination of AV_OPT_SEARCH_*. |
||
588 | * @param[out] target_obj if non-NULL, an object to which the option belongs will be |
||
589 | * written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present |
||
590 | * in search_flags. This parameter is ignored if search_flags contain |
||
591 | * AV_OPT_SEARCH_FAKE_OBJ. |
||
592 | * |
||
593 | * @return A pointer to the option found, or NULL if no option |
||
594 | * was found. |
||
595 | */ |
||
596 | const AVOption *av_opt_find2(void *obj, const char *name, const char *unit, |
||
597 | int opt_flags, int search_flags, void **target_obj); |
||
598 | |||
599 | /** |
||
600 | * Iterate over all AVOptions belonging to obj. |
||
601 | * |
||
602 | * @param obj an AVOptions-enabled struct or a double pointer to an |
||
603 | * AVClass describing it. |
||
604 | * @param prev result of the previous call to av_opt_next() on this object |
||
605 | * or NULL |
||
606 | * @return next AVOption or NULL |
||
607 | */ |
||
608 | const AVOption *av_opt_next(void *obj, const AVOption *prev); |
||
609 | |||
610 | /** |
||
611 | * Iterate over AVOptions-enabled children of obj. |
||
612 | * |
||
613 | * @param prev result of a previous call to this function or NULL |
||
614 | * @return next AVOptions-enabled child or NULL |
||
615 | */ |
||
616 | void *av_opt_child_next(void *obj, void *prev); |
||
617 | |||
618 | /** |
||
619 | * Iterate over potential AVOptions-enabled children of parent. |
||
620 | * |
||
621 | * @param prev result of a previous call to this function or NULL |
||
622 | * @return AVClass corresponding to next potential child or NULL |
||
623 | */ |
||
624 | const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev); |
||
625 | |||
626 | /** |
||
627 | * @defgroup opt_set_funcs Option setting functions |
||
628 | * @{ |
||
629 | * Those functions set the field of obj with the given name to value. |
||
630 | * |
||
631 | * @param[in] obj A struct whose first element is a pointer to an AVClass. |
||
632 | * @param[in] name the name of the field to set |
||
633 | * @param[in] val The value to set. In case of av_opt_set() if the field is not |
||
634 | * of a string type, then the given string is parsed. |
||
635 | * SI postfixes and some named scalars are supported. |
||
636 | * If the field is of a numeric type, it has to be a numeric or named |
||
637 | * scalar. Behavior with more than one scalar and +- infix operators |
||
638 | * is undefined. |
||
639 | * If the field is of a flags type, it has to be a sequence of numeric |
||
640 | * scalars or named flags separated by '+' or '-'. Prefixing a flag |
||
641 | * with '+' causes it to be set without affecting the other flags; |
||
642 | * similarly, '-' unsets a flag. |
||
643 | * @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
||
644 | * is passed here, then the option may be set on a child of obj. |
||
645 | * |
||
646 | * @return 0 if the value has been set, or an AVERROR code in case of |
||
647 | * error: |
||
648 | * AVERROR_OPTION_NOT_FOUND if no matching option exists |
||
649 | * AVERROR(ERANGE) if the value is out of range |
||
650 | * AVERROR(EINVAL) if the value is not valid |
||
651 | */ |
||
652 | int av_opt_set (void *obj, const char *name, const char *val, int search_flags); |
||
653 | int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags); |
||
654 | int av_opt_set_double(void *obj, const char *name, double val, int search_flags); |
||
655 | int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags); |
||
656 | int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags); |
||
657 | int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags); |
||
658 | int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags); |
||
659 | int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags); |
||
660 | int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags); |
||
661 | int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags); |
||
662 | |||
663 | /** |
||
664 | * Set a binary option to an integer list. |
||
665 | * |
||
666 | * @param obj AVClass object to set options on |
||
667 | * @param name name of the binary option |
||
668 | * @param val pointer to an integer list (must have the correct type with |
||
669 | * regard to the contents of the list) |
||
670 | * @param term list terminator (usually 0 or -1) |
||
671 | * @param flags search flags |
||
672 | */ |
||
673 | #define av_opt_set_int_list(obj, name, val, term, flags) \ |
||
674 | (av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \ |
||
675 | AVERROR(EINVAL) : \ |
||
676 | av_opt_set_bin(obj, name, (const uint8_t *)(val), \ |
||
677 | av_int_list_length(val, term) * sizeof(*(val)), flags)) |
||
678 | /** |
||
679 | * @} |
||
680 | */ |
||
681 | |||
682 | /** |
||
683 | * @defgroup opt_get_funcs Option getting functions |
||
684 | * @{ |
||
685 | * Those functions get a value of the option with the given name from an object. |
||
686 | * |
||
687 | * @param[in] obj a struct whose first element is a pointer to an AVClass. |
||
688 | * @param[in] name name of the option to get. |
||
689 | * @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
||
690 | * is passed here, then the option may be found in a child of obj. |
||
691 | * @param[out] out_val value of the option will be written here |
||
692 | * @return >=0 on success, a negative error code otherwise |
||
693 | */ |
||
694 | /** |
||
695 | * @note the returned string will be av_malloc()ed and must be av_free()ed by the caller |
||
696 | */ |
||
697 | int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val); |
||
698 | int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val); |
||
699 | int av_opt_get_double(void *obj, const char *name, int search_flags, double *out_val); |
||
700 | int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val); |
||
701 | int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out); |
||
702 | int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt); |
||
703 | int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt); |
||
704 | int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val); |
||
705 | int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout); |
||
706 | /** |
||
707 | * @} |
||
708 | */ |
||
709 | /** |
||
710 | * Gets a pointer to the requested field in a struct. |
||
711 | * This function allows accessing a struct even when its fields are moved or |
||
712 | * renamed since the application making the access has been compiled, |
||
713 | * |
||
714 | * @returns a pointer to the field, it can be cast to the correct type and read |
||
715 | * or written to. |
||
716 | */ |
||
717 | void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name); |
||
718 | |||
719 | /** |
||
720 | * Free an AVOptionRanges struct and set it to NULL. |
||
721 | */ |
||
722 | void av_opt_freep_ranges(AVOptionRanges **ranges); |
||
723 | |||
724 | /** |
||
725 | * Get a list of allowed ranges for the given option. |
||
726 | * |
||
727 | * The returned list may depend on other fields in obj like for example profile. |
||
728 | * |
||
729 | * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
||
730 | * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
||
731 | * |
||
732 | * The result must be freed with av_opt_freep_ranges. |
||
733 | * |
||
734 | * @return >= 0 on success, a negative errro code otherwise |
||
735 | */ |
||
736 | int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags); |
||
737 | |||
738 | /** |
||
739 | * Get a default list of allowed ranges for the given option. |
||
740 | * |
||
741 | * This list is constructed without using the AVClass.query_ranges() callback |
||
742 | * and can be used as fallback from within the callback. |
||
743 | * |
||
744 | * @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
||
745 | * AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
||
746 | * |
||
747 | * The result must be freed with av_opt_free_ranges. |
||
748 | * |
||
749 | * @return >= 0 on success, a negative errro code otherwise |
||
750 | */ |
||
751 | int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags); |
||
752 | |||
753 | /** |
||
754 | * @} |
||
755 | */ |
||
756 | |||
757 | #endif /* AVUTIL_OPT_H */>>>>>16)><16)>>>>>>>>>> |