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910 lines
37 KiB
910 lines
37 KiB
/* |
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* AVOptions |
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* copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVUTIL_OPT_H |
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#define AVUTIL_OPT_H |
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/** |
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* @file |
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* AVOptions |
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*/ |
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#include "rational.h" |
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#include "avutil.h" |
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#include "dict.h" |
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#include "log.h" |
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#include "pixfmt.h" |
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#include "samplefmt.h" |
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#include "version.h" |
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/** |
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* @defgroup avoptions AVOptions |
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* @ingroup lavu_data |
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* @{ |
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* AVOptions provide a generic system to declare options on arbitrary structs |
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* ("objects"). An option can have a help text, a type and a range of possible |
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* values. Options may then be enumerated, read and written to. |
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* |
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* @section avoptions_implement Implementing AVOptions |
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* This section describes how to add AVOptions capabilities to a struct. |
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* |
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* All AVOptions-related information is stored in an AVClass. Therefore |
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* the first member of the struct should be a pointer to an AVClass describing it. |
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* The option field of the AVClass must be set to a NULL-terminated static array |
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* of AVOptions. Each AVOption must have a non-empty name, a type, a default |
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* value and for number-type AVOptions also a range of allowed values. It must |
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* also declare an offset in bytes from the start of the struct, where the field |
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* associated with this AVOption is located. Other fields in the AVOption struct |
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* should also be set when applicable, but are not required. |
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* |
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* The following example illustrates an AVOptions-enabled struct: |
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* @code |
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* typedef struct test_struct { |
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* AVClass *class; |
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* int int_opt; |
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* char *str_opt; |
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* uint8_t *bin_opt; |
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* int bin_len; |
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* } test_struct; |
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* |
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* static const AVOption test_options[] = { |
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* { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt), |
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* AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX }, |
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* { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt), |
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* AV_OPT_TYPE_STRING }, |
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* { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt), |
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* AV_OPT_TYPE_BINARY }, |
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* { NULL }, |
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* }; |
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* |
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* static const AVClass test_class = { |
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* .class_name = "test class", |
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* .item_name = av_default_item_name, |
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* .option = test_options, |
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* .version = LIBAVUTIL_VERSION_INT, |
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* }; |
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* @endcode |
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* |
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* Next, when allocating your struct, you must ensure that the AVClass pointer |
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* is set to the correct value. Then, av_opt_set_defaults() can be called to |
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* initialize defaults. After that the struct is ready to be used with the |
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* AVOptions API. |
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* |
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* When cleaning up, you may use the av_opt_free() function to automatically |
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* free all the allocated string and binary options. |
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* |
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* Continuing with the above example: |
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* |
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* @code |
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* test_struct *alloc_test_struct(void) |
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* { |
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* test_struct *ret = av_malloc(sizeof(*ret)); |
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* ret->class = &test_class; |
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* av_opt_set_defaults(ret); |
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* return ret; |
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* } |
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* void free_test_struct(test_struct **foo) |
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* { |
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* av_opt_free(*foo); |
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* av_freep(foo); |
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* } |
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* @endcode |
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* |
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* @subsection avoptions_implement_nesting Nesting |
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* It may happen that an AVOptions-enabled struct contains another |
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* AVOptions-enabled struct as a member (e.g. AVCodecContext in |
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* libavcodec exports generic options, while its priv_data field exports |
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* codec-specific options). In such a case, it is possible to set up the |
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* parent struct to export a child's options. To do that, simply |
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* implement AVClass.child_next() and AVClass.child_class_next() in the |
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* parent struct's AVClass. |
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* Assuming that the test_struct from above now also contains a |
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* child_struct field: |
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* |
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* @code |
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* typedef struct child_struct { |
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* AVClass *class; |
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* int flags_opt; |
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* } child_struct; |
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* static const AVOption child_opts[] = { |
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* { "test_flags", "This is a test option of flags type.", |
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* offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX }, |
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* { NULL }, |
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* }; |
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* static const AVClass child_class = { |
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* .class_name = "child class", |
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* .item_name = av_default_item_name, |
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* .option = child_opts, |
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* .version = LIBAVUTIL_VERSION_INT, |
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* }; |
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* |
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* void *child_next(void *obj, void *prev) |
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* { |
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* test_struct *t = obj; |
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* if (!prev && t->child_struct) |
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* return t->child_struct; |
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* return NULL |
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* } |
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* const AVClass child_class_next(const AVClass *prev) |
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* { |
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* return prev ? NULL : &child_class; |
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* } |
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* @endcode |
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* Putting child_next() and child_class_next() as defined above into |
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* test_class will now make child_struct's options accessible through |
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* test_struct (again, proper setup as described above needs to be done on |
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* child_struct right after it is created). |
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* |
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* From the above example it might not be clear why both child_next() |
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* and child_class_next() are needed. The distinction is that child_next() |
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* iterates over actually existing objects, while child_class_next() |
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* iterates over all possible child classes. E.g. if an AVCodecContext |
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* was initialized to use a codec which has private options, then its |
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* child_next() will return AVCodecContext.priv_data and finish |
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* iterating. OTOH child_class_next() on AVCodecContext.av_class will |
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* iterate over all available codecs with private options. |
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* |
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* @subsection avoptions_implement_named_constants Named constants |
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* It is possible to create named constants for options. Simply set the unit |
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* field of the option the constants should apply to a string and |
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* create the constants themselves as options of type AV_OPT_TYPE_CONST |
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* with their unit field set to the same string. |
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* Their default_val field should contain the value of the named |
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* constant. |
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* For example, to add some named constants for the test_flags option |
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* above, put the following into the child_opts array: |
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* @code |
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* { "test_flags", "This is a test option of flags type.", |
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* offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT_MIN, INT_MAX, "test_unit" }, |
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* { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { .i64 = 16 }, 0, 0, "test_unit" }, |
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* @endcode |
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* |
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* @section avoptions_use Using AVOptions |
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* This section deals with accessing options in an AVOptions-enabled struct. |
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* Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or |
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* AVFormatContext in libavformat. |
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* |
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* @subsection avoptions_use_examine Examining AVOptions |
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* The basic functions for examining options are av_opt_next(), which iterates |
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* over all options defined for one object, and av_opt_find(), which searches |
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* for an option with the given name. |
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* |
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* The situation is more complicated with nesting. An AVOptions-enabled struct |
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* may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag |
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* to av_opt_find() will make the function search children recursively. |
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* |
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* For enumerating there are basically two cases. The first is when you want to |
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* get all options that may potentially exist on the struct and its children |
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* (e.g. when constructing documentation). In that case you should call |
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* av_opt_child_class_next() recursively on the parent struct's AVClass. The |
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* second case is when you have an already initialized struct with all its |
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* children and you want to get all options that can be actually written or read |
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* from it. In that case you should call av_opt_child_next() recursively (and |
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* av_opt_next() on each result). |
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* |
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* @subsection avoptions_use_get_set Reading and writing AVOptions |
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* When setting options, you often have a string read directly from the |
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* user. In such a case, simply passing it to av_opt_set() is enough. For |
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* non-string type options, av_opt_set() will parse the string according to the |
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* option type. |
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* |
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* Similarly av_opt_get() will read any option type and convert it to a string |
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* which will be returned. Do not forget that the string is allocated, so you |
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* have to free it with av_free(). |
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* |
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* In some cases it may be more convenient to put all options into an |
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* AVDictionary and call av_opt_set_dict() on it. A specific case of this |
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* are the format/codec open functions in lavf/lavc which take a dictionary |
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* filled with option as a parameter. This makes it possible to set some options |
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* that cannot be set otherwise, since e.g. the input file format is not known |
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* before the file is actually opened. |
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*/ |
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enum AVOptionType{ |
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AV_OPT_TYPE_FLAGS, |
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AV_OPT_TYPE_INT, |
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AV_OPT_TYPE_INT64, |
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AV_OPT_TYPE_DOUBLE, |
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AV_OPT_TYPE_FLOAT, |
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AV_OPT_TYPE_STRING, |
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AV_OPT_TYPE_RATIONAL, |
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AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length |
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AV_OPT_TYPE_DICT, |
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AV_OPT_TYPE_CONST = 128, |
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AV_OPT_TYPE_IMAGE_SIZE = MKBETAG('S','I','Z','E'), ///< offset must point to two consecutive integers |
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AV_OPT_TYPE_PIXEL_FMT = MKBETAG('P','F','M','T'), |
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AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'), |
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AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational |
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AV_OPT_TYPE_DURATION = MKBETAG('D','U','R',' '), |
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AV_OPT_TYPE_COLOR = MKBETAG('C','O','L','R'), |
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AV_OPT_TYPE_CHANNEL_LAYOUT = MKBETAG('C','H','L','A'), |
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#if FF_API_OLD_AVOPTIONS |
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FF_OPT_TYPE_FLAGS = 0, |
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FF_OPT_TYPE_INT, |
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FF_OPT_TYPE_INT64, |
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FF_OPT_TYPE_DOUBLE, |
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FF_OPT_TYPE_FLOAT, |
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FF_OPT_TYPE_STRING, |
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FF_OPT_TYPE_RATIONAL, |
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FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length |
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FF_OPT_TYPE_CONST=128, |
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#endif |
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}; |
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/** |
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* AVOption |
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*/ |
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typedef struct AVOption { |
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const char *name; |
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/** |
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* short English help text |
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* @todo What about other languages? |
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*/ |
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const char *help; |
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/** |
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* The offset relative to the context structure where the option |
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* value is stored. It should be 0 for named constants. |
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*/ |
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int offset; |
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enum AVOptionType type; |
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/** |
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* the default value for scalar options |
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*/ |
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union { |
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int64_t i64; |
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double dbl; |
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const char *str; |
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/* TODO those are unused now */ |
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AVRational q; |
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} default_val; |
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double min; ///< minimum valid value for the option |
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double max; ///< maximum valid value for the option |
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int flags; |
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#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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#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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#if FF_API_OPT_TYPE_METADATA |
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#define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ... |
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#endif |
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#define AV_OPT_FLAG_AUDIO_PARAM 8 |
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#define AV_OPT_FLAG_VIDEO_PARAM 16 |
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#define AV_OPT_FLAG_SUBTITLE_PARAM 32 |
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/** |
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* The option is inteded for exporting values to the caller. |
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*/ |
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#define AV_OPT_FLAG_EXPORT 64 |
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/** |
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* The option may not be set through the AVOptions API, only read. |
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* This flag only makes sense when AV_OPT_FLAG_EXPORT is also set. |
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*/ |
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#define AV_OPT_FLAG_READONLY 128 |
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#define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering |
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//FIXME think about enc-audio, ... style flags |
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/** |
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* The logical unit to which the option belongs. Non-constant |
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* options and corresponding named constants share the same |
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* unit. May be NULL. |
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*/ |
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const char *unit; |
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} AVOption; |
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/** |
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* A single allowed range of values, or a single allowed value. |
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*/ |
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typedef struct AVOptionRange { |
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const char *str; |
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/** |
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* Value range. |
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* For string ranges this represents the min/max length. |
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* For dimensions this represents the min/max pixel count or width/height in multi-component case. |
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*/ |
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double value_min, value_max; |
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/** |
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* Value's component range. |
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* For string this represents the unicode range for chars, 0-127 limits to ASCII. |
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*/ |
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double component_min, component_max; |
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/** |
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* Range flag. |
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* If set to 1 the struct encodes a range, if set to 0 a single value. |
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*/ |
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int is_range; |
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} AVOptionRange; |
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/** |
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* List of AVOptionRange structs. |
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*/ |
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typedef struct AVOptionRanges { |
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/** |
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* Array of option ranges. |
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* |
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* Most of option types use just one component. |
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* Following describes multi-component option types: |
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* |
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* AV_OPT_TYPE_IMAGE_SIZE: |
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* component index 0: range of pixel count (width * height). |
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* component index 1: range of width. |
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* component index 2: range of height. |
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* |
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* @note To obtain multi-component version of this structure, user must |
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* provide AV_OPT_MULTI_COMPONENT_RANGE to av_opt_query_ranges or |
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* av_opt_query_ranges_default function. |
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* |
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* Multi-component range can be read as in following example: |
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* |
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* @code |
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* int range_index, component_index; |
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* AVOptionRanges *ranges; |
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* AVOptionRange *range[3]; //may require more than 3 in the future. |
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* av_opt_query_ranges(&ranges, obj, key, AV_OPT_MULTI_COMPONENT_RANGE); |
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* for (range_index = 0; range_index < ranges->nb_ranges; range_index++) { |
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* for (component_index = 0; component_index < ranges->nb_components; component_index++) |
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* range[component_index] = ranges->range[ranges->nb_ranges * component_index + range_index]; |
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* //do something with range here. |
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* } |
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* av_opt_freep_ranges(&ranges); |
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* @endcode |
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*/ |
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AVOptionRange **range; |
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/** |
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* Number of ranges per component. |
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*/ |
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int nb_ranges; |
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/** |
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* Number of componentes. |
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*/ |
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int nb_components; |
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} AVOptionRanges; |
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#if FF_API_OLD_AVOPTIONS |
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/** |
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* Set the field of obj with the given name to value. |
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* |
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* @param[in] obj A struct whose first element is a pointer to an |
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* AVClass. |
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* @param[in] name the name of the field to set |
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* @param[in] val The value to set. If the field is not of a string |
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* type, then the given string is parsed. |
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* SI postfixes and some named scalars are supported. |
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* If the field is of a numeric type, it has to be a numeric or named |
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* scalar. Behavior with more than one scalar and +- infix operators |
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* is undefined. |
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* If the field is of a flags type, it has to be a sequence of numeric |
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* scalars or named flags separated by '+' or '-'. Prefixing a flag |
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* with '+' causes it to be set without affecting the other flags; |
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* similarly, '-' unsets a flag. |
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* @param[out] o_out if non-NULL put here a pointer to the AVOption |
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* found |
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* @param alloc this parameter is currently ignored |
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* @return 0 if the value has been set, or an AVERROR code in case of |
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* error: |
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* AVERROR_OPTION_NOT_FOUND if no matching option exists |
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* AVERROR(ERANGE) if the value is out of range |
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* AVERROR(EINVAL) if the value is not valid |
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* @deprecated use av_opt_set() |
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*/ |
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attribute_deprecated |
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int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out); |
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attribute_deprecated const AVOption *av_set_double(void *obj, const char *name, double n); |
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attribute_deprecated const AVOption *av_set_q(void *obj, const char *name, AVRational n); |
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attribute_deprecated const AVOption *av_set_int(void *obj, const char *name, int64_t n); |
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attribute_deprecated |
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double av_get_double(void *obj, const char *name, const AVOption **o_out); |
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attribute_deprecated |
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AVRational av_get_q(void *obj, const char *name, const AVOption **o_out); |
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attribute_deprecated |
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int64_t av_get_int(void *obj, const char *name, const AVOption **o_out); |
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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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attribute_deprecated const AVOption *av_next_option(FF_CONST_AVUTIL55 void *obj, const AVOption *last); |
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#endif |
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/** |
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* Show the obj options. |
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* |
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* @param req_flags requested flags for the options to show. Show only the |
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* options for which it is opt->flags & req_flags. |
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* @param rej_flags rejected flags for the options to show. Show only the |
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* options for which it is !(opt->flags & req_flags). |
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* @param av_log_obj log context to use for showing the options |
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*/ |
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int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags); |
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/** |
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* Set the values of all AVOption fields to their default values. |
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* |
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* @param s an AVOption-enabled struct (its first member must be a pointer to AVClass) |
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*/ |
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void av_opt_set_defaults(void *s); |
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/** |
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* Set the values of all AVOption fields to their default values. Only these |
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* AVOption fields for which (opt->flags & mask) == flags will have their |
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* default applied to s. |
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* |
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* @param s an AVOption-enabled struct (its first member must be a pointer to AVClass) |
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* @param mask combination of AV_OPT_FLAG_* |
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* @param flags combination of AV_OPT_FLAG_* |
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*/ |
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void av_opt_set_defaults2(void *s, int mask, int flags); |
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|
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/** |
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* Parse the key/value pairs list in opts. For each key/value pair |
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* found, stores the value in the field in ctx that is named like the |
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* key. ctx must be an AVClass context, storing is done using |
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* AVOptions. |
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* |
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* @param opts options string to parse, may be NULL |
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* @param key_val_sep a 0-terminated list of characters used to |
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* separate key from value |
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* @param pairs_sep a 0-terminated list of characters used to separate |
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* two pairs from each other |
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* @return the number of successfully set key/value pairs, or a negative |
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* value corresponding to an AVERROR code in case of error: |
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* AVERROR(EINVAL) if opts cannot be parsed, |
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* the error code issued by av_opt_set() if a key/value pair |
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* cannot be set |
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*/ |
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int av_set_options_string(void *ctx, const char *opts, |
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const char *key_val_sep, const char *pairs_sep); |
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|
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/** |
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* Parse the key-value pairs list in opts. For each key=value pair found, |
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* set the value of the corresponding option in ctx. |
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* |
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* @param ctx the AVClass object to set options on |
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* @param opts the options string, key-value pairs separated by a |
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* delimiter |
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* @param shorthand a NULL-terminated array of options names for shorthand |
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* notation: if the first field in opts has no key part, |
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* the key is taken from the first element of shorthand; |
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* then again for the second, etc., until either opts is |
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* finished, shorthand is finished or a named option is |
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* found; after that, all options must be named |
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* @param key_val_sep a 0-terminated list of characters used to separate |
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* key from value, for example '=' |
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* @param pairs_sep a 0-terminated list of characters used to separate |
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* two pairs from each other, for example ':' or ',' |
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* @return the number of successfully set key=value pairs, or a negative |
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* value corresponding to an AVERROR code in case of error: |
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* AVERROR(EINVAL) if opts cannot be parsed, |
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* the error code issued by av_set_string3() if a key/value pair |
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* cannot be set |
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* |
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* Options names must use only the following characters: a-z A-Z 0-9 - . / _ |
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* Separators must use characters distinct from option names and from each |
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* other. |
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*/ |
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int av_opt_set_from_string(void *ctx, const char *opts, |
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const char *const *shorthand, |
|
const char *key_val_sep, const char *pairs_sep); |
|
/** |
|
* Free all allocated objects in obj. |
|
*/ |
|
void av_opt_free(void *obj); |
|
|
|
/** |
|
* Check whether a particular flag is set in a flags field. |
|
* |
|
* @param field_name the name of the flag field option |
|
* @param flag_name the name of the flag to check |
|
* @return non-zero if the flag is set, zero if the flag isn't set, |
|
* isn't of the right type, or the flags field doesn't exist. |
|
*/ |
|
int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name); |
|
|
|
/** |
|
* Set all the options from a given dictionary on an object. |
|
* |
|
* @param obj a struct whose first element is a pointer to AVClass |
|
* @param options options to process. This dictionary will be freed and replaced |
|
* by a new one containing all options not found in obj. |
|
* Of course this new dictionary needs to be freed by caller |
|
* with av_dict_free(). |
|
* |
|
* @return 0 on success, a negative AVERROR if some option was found in obj, |
|
* but could not be set. |
|
* |
|
* @see av_dict_copy() |
|
*/ |
|
int av_opt_set_dict(void *obj, struct AVDictionary **options); |
|
|
|
|
|
/** |
|
* Set all the options from a given dictionary on an object. |
|
* |
|
* @param obj a struct whose first element is a pointer to AVClass |
|
* @param options options to process. This dictionary will be freed and replaced |
|
* by a new one containing all options not found in obj. |
|
* Of course this new dictionary needs to be freed by caller |
|
* with av_dict_free(). |
|
* @param search_flags A combination of AV_OPT_SEARCH_*. |
|
* |
|
* @return 0 on success, a negative AVERROR if some option was found in obj, |
|
* but could not be set. |
|
* |
|
* @see av_dict_copy() |
|
*/ |
|
int av_opt_set_dict2(void *obj, struct AVDictionary **options, int search_flags); |
|
|
|
/** |
|
* Extract a key-value pair from the beginning of a string. |
|
* |
|
* @param ropts pointer to the options string, will be updated to |
|
* point to the rest of the string (one of the pairs_sep |
|
* or the final NUL) |
|
* @param key_val_sep a 0-terminated list of characters used to separate |
|
* key from value, for example '=' |
|
* @param pairs_sep a 0-terminated list of characters used to separate |
|
* two pairs from each other, for example ':' or ',' |
|
* @param flags flags; see the AV_OPT_FLAG_* values below |
|
* @param rkey parsed key; must be freed using av_free() |
|
* @param rval parsed value; must be freed using av_free() |
|
* |
|
* @return >=0 for success, or a negative value corresponding to an |
|
* AVERROR code in case of error; in particular: |
|
* AVERROR(EINVAL) if no key is present |
|
* |
|
*/ |
|
int av_opt_get_key_value(const char **ropts, |
|
const char *key_val_sep, const char *pairs_sep, |
|
unsigned flags, |
|
char **rkey, char **rval); |
|
|
|
enum { |
|
|
|
/** |
|
* Accept to parse a value without a key; the key will then be returned |
|
* as NULL. |
|
*/ |
|
AV_OPT_FLAG_IMPLICIT_KEY = 1, |
|
}; |
|
|
|
/** |
|
* @defgroup opt_eval_funcs Evaluating option strings |
|
* @{ |
|
* This group of functions can be used to evaluate option strings |
|
* and get numbers out of them. They do the same thing as av_opt_set(), |
|
* except the result is written into the caller-supplied pointer. |
|
* |
|
* @param obj a struct whose first element is a pointer to AVClass. |
|
* @param o an option for which the string is to be evaluated. |
|
* @param val string to be evaluated. |
|
* @param *_out value of the string will be written here. |
|
* |
|
* @return 0 on success, a negative number on failure. |
|
*/ |
|
int av_opt_eval_flags (void *obj, const AVOption *o, const char *val, int *flags_out); |
|
int av_opt_eval_int (void *obj, const AVOption *o, const char *val, int *int_out); |
|
int av_opt_eval_int64 (void *obj, const AVOption *o, const char *val, int64_t *int64_out); |
|
int av_opt_eval_float (void *obj, const AVOption *o, const char *val, float *float_out); |
|
int av_opt_eval_double(void *obj, const AVOption *o, const char *val, double *double_out); |
|
int av_opt_eval_q (void *obj, const AVOption *o, const char *val, AVRational *q_out); |
|
/** |
|
* @} |
|
*/ |
|
|
|
#define AV_OPT_SEARCH_CHILDREN 0x0001 /**< Search in possible children of the |
|
given object first. */ |
|
/** |
|
* The obj passed to av_opt_find() is fake -- only a double pointer to AVClass |
|
* instead of a required pointer to a struct containing AVClass. This is |
|
* useful for searching for options without needing to allocate the corresponding |
|
* object. |
|
*/ |
|
#define AV_OPT_SEARCH_FAKE_OBJ 0x0002 |
|
|
|
/** |
|
* Allows av_opt_query_ranges and av_opt_query_ranges_default to return more than |
|
* one component for certain option types. |
|
* @see AVOptionRanges for details. |
|
*/ |
|
#define AV_OPT_MULTI_COMPONENT_RANGE 0x1000 |
|
|
|
/** |
|
* Look for an option in an object. Consider only options which |
|
* have all the specified flags set. |
|
* |
|
* @param[in] obj A pointer to a struct whose first element is a |
|
* pointer to an AVClass. |
|
* Alternatively a double pointer to an AVClass, if |
|
* AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
|
* @param[in] name The name of the option to look for. |
|
* @param[in] unit When searching for named constants, name of the unit |
|
* it belongs to. |
|
* @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
|
* @param search_flags A combination of AV_OPT_SEARCH_*. |
|
* |
|
* @return A pointer to the option found, or NULL if no option |
|
* was found. |
|
* |
|
* @note Options found with AV_OPT_SEARCH_CHILDREN flag may not be settable |
|
* directly with av_opt_set(). Use special calls which take an options |
|
* AVDictionary (e.g. avformat_open_input()) to set options found with this |
|
* flag. |
|
*/ |
|
const AVOption *av_opt_find(void *obj, const char *name, const char *unit, |
|
int opt_flags, int search_flags); |
|
|
|
/** |
|
* Look for an option in an object. Consider only options which |
|
* have all the specified flags set. |
|
* |
|
* @param[in] obj A pointer to a struct whose first element is a |
|
* pointer to an AVClass. |
|
* Alternatively a double pointer to an AVClass, if |
|
* AV_OPT_SEARCH_FAKE_OBJ search flag is set. |
|
* @param[in] name The name of the option to look for. |
|
* @param[in] unit When searching for named constants, name of the unit |
|
* it belongs to. |
|
* @param opt_flags Find only options with all the specified flags set (AV_OPT_FLAG). |
|
* @param search_flags A combination of AV_OPT_SEARCH_*. |
|
* @param[out] target_obj if non-NULL, an object to which the option belongs will be |
|
* written here. It may be different from obj if AV_OPT_SEARCH_CHILDREN is present |
|
* in search_flags. This parameter is ignored if search_flags contain |
|
* AV_OPT_SEARCH_FAKE_OBJ. |
|
* |
|
* @return A pointer to the option found, or NULL if no option |
|
* was found. |
|
*/ |
|
const AVOption *av_opt_find2(void *obj, const char *name, const char *unit, |
|
int opt_flags, int search_flags, void **target_obj); |
|
|
|
/** |
|
* Iterate over all AVOptions belonging to obj. |
|
* |
|
* @param obj an AVOptions-enabled struct or a double pointer to an |
|
* AVClass describing it. |
|
* @param prev result of the previous call to av_opt_next() on this object |
|
* or NULL |
|
* @return next AVOption or NULL |
|
*/ |
|
const AVOption *av_opt_next(FF_CONST_AVUTIL55 void *obj, const AVOption *prev); |
|
|
|
/** |
|
* Iterate over AVOptions-enabled children of obj. |
|
* |
|
* @param prev result of a previous call to this function or NULL |
|
* @return next AVOptions-enabled child or NULL |
|
*/ |
|
void *av_opt_child_next(void *obj, void *prev); |
|
|
|
/** |
|
* Iterate over potential AVOptions-enabled children of parent. |
|
* |
|
* @param prev result of a previous call to this function or NULL |
|
* @return AVClass corresponding to next potential child or NULL |
|
*/ |
|
const AVClass *av_opt_child_class_next(const AVClass *parent, const AVClass *prev); |
|
|
|
/** |
|
* @defgroup opt_set_funcs Option setting functions |
|
* @{ |
|
* Those functions set the field of obj with the given name to value. |
|
* |
|
* @param[in] obj A struct whose first element is a pointer to an AVClass. |
|
* @param[in] name the name of the field to set |
|
* @param[in] val The value to set. In case of av_opt_set() if the field is not |
|
* of a string type, then the given string is parsed. |
|
* SI postfixes and some named scalars are supported. |
|
* If the field is of a numeric type, it has to be a numeric or named |
|
* scalar. Behavior with more than one scalar and +- infix operators |
|
* is undefined. |
|
* If the field is of a flags type, it has to be a sequence of numeric |
|
* scalars or named flags separated by '+' or '-'. Prefixing a flag |
|
* with '+' causes it to be set without affecting the other flags; |
|
* similarly, '-' unsets a flag. |
|
* @param search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
|
* is passed here, then the option may be set on a child of obj. |
|
* |
|
* @return 0 if the value has been set, or an AVERROR code in case of |
|
* error: |
|
* AVERROR_OPTION_NOT_FOUND if no matching option exists |
|
* AVERROR(ERANGE) if the value is out of range |
|
* AVERROR(EINVAL) if the value is not valid |
|
*/ |
|
int av_opt_set (void *obj, const char *name, const char *val, int search_flags); |
|
int av_opt_set_int (void *obj, const char *name, int64_t val, int search_flags); |
|
int av_opt_set_double (void *obj, const char *name, double val, int search_flags); |
|
int av_opt_set_q (void *obj, const char *name, AVRational val, int search_flags); |
|
int av_opt_set_bin (void *obj, const char *name, const uint8_t *val, int size, int search_flags); |
|
int av_opt_set_image_size(void *obj, const char *name, int w, int h, int search_flags); |
|
int av_opt_set_pixel_fmt (void *obj, const char *name, enum AVPixelFormat fmt, int search_flags); |
|
int av_opt_set_sample_fmt(void *obj, const char *name, enum AVSampleFormat fmt, int search_flags); |
|
int av_opt_set_video_rate(void *obj, const char *name, AVRational val, int search_flags); |
|
int av_opt_set_channel_layout(void *obj, const char *name, int64_t ch_layout, int search_flags); |
|
/** |
|
* @note Any old dictionary present is discarded and replaced with a copy of the new one. The |
|
* caller still owns val is and responsible for freeing it. |
|
*/ |
|
int av_opt_set_dict_val(void *obj, const char *name, const AVDictionary *val, int search_flags); |
|
|
|
/** |
|
* Set a binary option to an integer list. |
|
* |
|
* @param obj AVClass object to set options on |
|
* @param name name of the binary option |
|
* @param val pointer to an integer list (must have the correct type with |
|
* regard to the contents of the list) |
|
* @param term list terminator (usually 0 or -1) |
|
* @param flags search flags |
|
*/ |
|
#define av_opt_set_int_list(obj, name, val, term, flags) \ |
|
(av_int_list_length(val, term) > INT_MAX / sizeof(*(val)) ? \ |
|
AVERROR(EINVAL) : \ |
|
av_opt_set_bin(obj, name, (const uint8_t *)(val), \ |
|
av_int_list_length(val, term) * sizeof(*(val)), flags)) |
|
|
|
/** |
|
* @} |
|
*/ |
|
|
|
/** |
|
* @defgroup opt_get_funcs Option getting functions |
|
* @{ |
|
* Those functions get a value of the option with the given name from an object. |
|
* |
|
* @param[in] obj a struct whose first element is a pointer to an AVClass. |
|
* @param[in] name name of the option to get. |
|
* @param[in] search_flags flags passed to av_opt_find2. I.e. if AV_OPT_SEARCH_CHILDREN |
|
* is passed here, then the option may be found in a child of obj. |
|
* @param[out] out_val value of the option will be written here |
|
* @return >=0 on success, a negative error code otherwise |
|
*/ |
|
/** |
|
* @note the returned string will be av_malloc()ed and must be av_free()ed by the caller |
|
*/ |
|
int av_opt_get (void *obj, const char *name, int search_flags, uint8_t **out_val); |
|
int av_opt_get_int (void *obj, const char *name, int search_flags, int64_t *out_val); |
|
int av_opt_get_double (void *obj, const char *name, int search_flags, double *out_val); |
|
int av_opt_get_q (void *obj, const char *name, int search_flags, AVRational *out_val); |
|
int av_opt_get_image_size(void *obj, const char *name, int search_flags, int *w_out, int *h_out); |
|
int av_opt_get_pixel_fmt (void *obj, const char *name, int search_flags, enum AVPixelFormat *out_fmt); |
|
int av_opt_get_sample_fmt(void *obj, const char *name, int search_flags, enum AVSampleFormat *out_fmt); |
|
int av_opt_get_video_rate(void *obj, const char *name, int search_flags, AVRational *out_val); |
|
int av_opt_get_channel_layout(void *obj, const char *name, int search_flags, int64_t *ch_layout); |
|
/** |
|
* @param[out] out_val The returned dictionary is a copy of the actual value and must |
|
* be freed with av_dict_free() by the caller |
|
*/ |
|
int av_opt_get_dict_val(void *obj, const char *name, int search_flags, AVDictionary **out_val); |
|
/** |
|
* @} |
|
*/ |
|
/** |
|
* Gets a pointer to the requested field in a struct. |
|
* This function allows accessing a struct even when its fields are moved or |
|
* renamed since the application making the access has been compiled, |
|
* |
|
* @returns a pointer to the field, it can be cast to the correct type and read |
|
* or written to. |
|
*/ |
|
void *av_opt_ptr(const AVClass *avclass, void *obj, const char *name); |
|
|
|
/** |
|
* Free an AVOptionRanges struct and set it to NULL. |
|
*/ |
|
void av_opt_freep_ranges(AVOptionRanges **ranges); |
|
|
|
/** |
|
* Get a list of allowed ranges for the given option. |
|
* |
|
* The returned list may depend on other fields in obj like for example profile. |
|
* |
|
* @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
|
* AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
|
* AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges |
|
* |
|
* The result must be freed with av_opt_freep_ranges. |
|
* |
|
* @return number of compontents returned on success, a negative errro code otherwise |
|
*/ |
|
int av_opt_query_ranges(AVOptionRanges **, void *obj, const char *key, int flags); |
|
|
|
/** |
|
* Copy options from src object into dest object. |
|
* |
|
* Options that require memory allocation (e.g. string or binary) are malloc'ed in dest object. |
|
* Original memory allocated for such options is freed unless both src and dest options points to the same memory. |
|
* |
|
* @param dest Object to copy from |
|
* @param src Object to copy into |
|
* @return 0 on success, negative on error |
|
*/ |
|
int av_opt_copy(void *dest, FF_CONST_AVUTIL55 void *src); |
|
|
|
/** |
|
* Get a default list of allowed ranges for the given option. |
|
* |
|
* This list is constructed without using the AVClass.query_ranges() callback |
|
* and can be used as fallback from within the callback. |
|
* |
|
* @param flags is a bitmask of flags, undefined flags should not be set and should be ignored |
|
* AV_OPT_SEARCH_FAKE_OBJ indicates that the obj is a double pointer to a AVClass instead of a full instance |
|
* AV_OPT_MULTI_COMPONENT_RANGE indicates that function may return more than one component, @see AVOptionRanges |
|
* |
|
* The result must be freed with av_opt_free_ranges. |
|
* |
|
* @return number of compontents returned on success, a negative errro code otherwise |
|
*/ |
|
int av_opt_query_ranges_default(AVOptionRanges **, void *obj, const char *key, int flags); |
|
|
|
/** |
|
* Check if given option is set to its default value. |
|
* |
|
* Options o must belong to the obj. This function must not be called to check child's options state. |
|
* @see av_opt_is_set_to_default_by_name(). |
|
* |
|
* @param obj AVClass object to check option on |
|
* @param o option to be checked |
|
* @return >0 when option is set to its default, |
|
* 0 when option is not set its default, |
|
* <0 on error |
|
*/ |
|
int av_opt_is_set_to_default(void *obj, const AVOption *o); |
|
|
|
/** |
|
* Check if given option is set to its default value. |
|
* |
|
* @param obj AVClass object to check option on |
|
* @param name option name |
|
* @param search_flags combination of AV_OPT_SEARCH_* |
|
* @return >0 when option is set to its default, |
|
* 0 when option is not set its default, |
|
* <0 on error |
|
*/ |
|
int av_opt_is_set_to_default_by_name(void *obj, const char *name, int search_flags); |
|
|
|
|
|
#define AV_OPT_SERIALIZE_SKIP_DEFAULTS 0x00000001 ///< Serialize options that are not set to default values only. |
|
#define AV_OPT_SERIALIZE_OPT_FLAGS_EXACT 0x00000002 ///< Serialize options that exactly match opt_flags only. |
|
|
|
/** |
|
* Serialize object's options. |
|
* |
|
* Create a string containing object's serialized options. |
|
* Such string may be passed back to av_opt_set_from_string() in order to restore option values. |
|
* A key/value or pairs separator occurring in the serialized value or |
|
* name string are escaped through the av_escape() function. |
|
* |
|
* @param[in] obj AVClass object to serialize |
|
* @param[in] opt_flags serialize options with all the specified flags set (AV_OPT_FLAG) |
|
* @param[in] flags combination of AV_OPT_SERIALIZE_* flags |
|
* @param[out] buffer Pointer to buffer that will be allocated with string containg serialized options. |
|
* Buffer must be freed by the caller when is no longer needed. |
|
* @param[in] key_val_sep character used to separate key from value |
|
* @param[in] pairs_sep character used to separate two pairs from each other |
|
* @return >= 0 on success, negative on error |
|
* @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same. |
|
*/ |
|
int av_opt_serialize(void *obj, int opt_flags, int flags, char **buffer, |
|
const char key_val_sep, const char pairs_sep); |
|
/** |
|
* @} |
|
*/ |
|
|
|
#endif /* AVUTIL_OPT_H */
|
|
|