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Diffstat (limited to 'src/lib/ffmpeg-0.10/libavutil/opt.pas')
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diff --git a/src/lib/ffmpeg-0.10/libavutil/opt.pas b/src/lib/ffmpeg-0.10/libavutil/opt.pas new file mode 100644 index 00000000..6d5b3c89 --- /dev/null +++ b/src/lib/ffmpeg-0.10/libavutil/opt.pas @@ -0,0 +1,659 @@ +(* + * AVOptions + * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * This is a part of Pascal porting of ffmpeg. + * - Originally by Victor Zinetz for Delphi and Free Pascal on Windows. + * - For Mac OS X, some modifications were made by The Creative CAT, denoted as CAT + * in the source codes. + * - Changes and updates by the UltraStar Deluxe Team + * + * Conversion of libavutil/opt.h + * avutil version 51.34.101 + * + *) + +unit opt; + +{$IFDEF FPC} + {$MODE DELPHI} + {$PACKENUM 4} (* use 4-byte enums *) + {$PACKRECORDS C} (* C/C++-compatible record packing *) +{$ELSE} + {$MINENUMSIZE 4} (* use 4-byte enums *) +{$ENDIF} + +interface + +uses + ctypes, + dict, + rational, + UConfig; + +(** + * @defgroup avoptions AVOptions + * @ingroup lavu_data + * @{ + * AVOptions provide a generic system to declare options on arbitrary structs + * ("objects"). An option can have a help text, a type and a range of possible + * values. Options may then be enumerated, read and written to. + * + * @section avoptions_implement Implementing AVOptions + * This section describes how to add AVOptions capabilities to a struct. + * + * All AVOptions-related information is stored in an AVClass. Therefore + * the first member of the struct must be a pointer to an AVClass describing it. + * The option field of the AVClass must be set to a NULL-terminated static array + * of AVOptions. Each AVOption must have a non-empty name, a type, a default + * value and for number-type AVOptions also a range of allowed values. It must + * also declare an offset in bytes from the start of the struct, where the field + * associated with this AVOption is located. Other fields in the AVOption struct + * should also be set when applicable, but are not required. + * + * The following example illustrates an AVOptions-enabled struct: + * @code + * typedef struct test_struct { + * AVClass *class; + * int int_opt; + * char *str_opt; + * uint8_t *bin_opt; + * int bin_len; + * } test_struct; + * + * static const AVOption options[] = { + * { "test_int", "This is a test option of int type.", offsetof(test_struct, int_opt), + * AV_OPT_TYPE_INT, { -1 }, INT_MIN, INT_MAX }, + * { "test_str", "This is a test option of string type.", offsetof(test_struct, str_opt), + * AV_OPT_TYPE_STRING }, + * { "test_bin", "This is a test option of binary type.", offsetof(test_struct, bin_opt), + * AV_OPT_TYPE_BINARY }, + * { NULL }, + * }; + * + * static const AVClass test_class = { + * .class_name = "test class", + * .item_name = av_default_item_name, + * .option = options, + * .version = LIBAVUTIL_VERSION_INT, + * }; + * @endcode + * + * Next, when allocating your struct, you must ensure that the AVClass pointer + * is set to the correct value. Then, av_opt_set_defaults() must be called to + * initialize defaults. After that the struct is ready to be used with the + * AVOptions API. + * + * When cleaning up, you may use the av_opt_free() function to automatically + * free all the allocated string and binary options. + * + * Continuing with the above example: + * + * @code + * test_struct *alloc_test_struct(void) + * { + * test_struct *ret = av_malloc(sizeof(*ret)); + * ret->class = &test_class; + * av_opt_set_defaults(ret); + * return ret; + * } + * void free_test_struct(test_struct **foo) + * { + * av_opt_free(*foo); + * av_freep(foo); + * } + * @endcode + * + * @subsection avoptions_implement_nesting Nesting + * It may happen that an AVOptions-enabled struct contains another + * AVOptions-enabled struct as a member (e.g. AVCodecContext in + * libavcodec exports generic options, while its priv_data field exports + * codec-specific options). In such a case, it is possible to set up the + * parent struct to export a child's options. To do that, simply + * implement AVClass.child_next() and AVClass.child_class_next() in the + * parent struct's AVClass. + * Assuming that the test_struct from above now also contains a + * child_struct field: + * + * @code + * typedef struct child_struct { + * AVClass *class; + * int flags_opt; + * } child_struct; + * static const AVOption child_opts[] = { + * { "test_flags", "This is a test option of flags type.", + * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { 0 }, INT_MIN, INT_MAX }, + * { NULL }, + * }; + * static const AVClass child_class = { + * .class_name = "child class", + * .item_name = av_default_item_name, + * .option = child_opts, + * .version = LIBAVUTIL_VERSION_INT, + * }; + * + * void *child_next(void *obj, void *prev) + * { + * test_struct *t = obj; + * if (!prev && t->child_struct) + * return t->child_struct; + * return NULL + * } + * const AVClass child_class_next(const AVClass *prev) + * { + * return prev ? NULL : &child_class; + * } + * @endcode + * Putting child_next() and child_class_next() as defined above into + * test_class will now make child_struct's options accessible through + * test_struct (again, proper setup as described above needs to be done on + * child_struct right after it is created). + * + * From the above example it might not be clear why both child_next() + * and child_class_next() are needed. The distinction is that child_next() + * iterates over actually existing objects, while child_class_next() + * iterates over all possible child classes. E.g. if an AVCodecContext + * was initialized to use a codec which has private options, then its + * child_next() will return AVCodecContext.priv_data and finish + * iterating. OTOH child_class_next() on AVCodecContext.av_class will + * iterate over all available codecs with private options. + * + * @subsection avoptions_implement_named_constants Named constants + * It is possible to create named constants for options. Simply set the unit + * field of the option the constants should apply to to a string and + * create the constants themselves as options of type AV_OPT_TYPE_CONST + * with their unit field set to the same string. + * Their default_val field should contain the value of the named + * constant. + * For example, to add some named constants for the test_flags option + * above, put the following into the child_opts array: + * @code + * { "test_flags", "This is a test option of flags type.", + * offsetof(child_struct, flags_opt), AV_OPT_TYPE_FLAGS, { 0 }, INT_MIN, INT_MAX, "test_unit" }, + * { "flag1", "This is a flag with value 16", 0, AV_OPT_TYPE_CONST, { 16 }, 0, 0, "test_unit" }, + * @endcode + * + * @section avoptions_use Using AVOptions + * This section deals with accessing options in an AVOptions-enabled struct. + * Such structs in FFmpeg are e.g. AVCodecContext in libavcodec or + * AVFormatContext in libavformat. + * + * @subsection avoptions_use_examine Examining AVOptions + * The basic functions for examining options are av_opt_next(), which iterates + * over all options defined for one object, and av_opt_find(), which searches + * for an option with the given name. + * + * The situation is more complicated with nesting. An AVOptions-enabled struct + * may have AVOptions-enabled children. Passing the AV_OPT_SEARCH_CHILDREN flag + * to av_opt_find() will make the function search children recursively. + * + * For enumerating there are basically two cases. The first is when you want to + * get all options that may potentially exist on the struct and its children + * (e.g. when constructing documentation). In that case you should call + * av_opt_child_class_next() recursively on the parent struct's AVClass. The + * second case is when you have an already initialized struct with all its + * children and you want to get all options that can be actually written or read + * from it. In that case you should call av_opt_child_next() recursively (and + * av_opt_next() on each result). + * + * @subsection avoptions_use_get_set Reading and writing AVOptions + * When setting options, you often have a string read directly from the + * user. In such a case, simply passing it to av_opt_set() is enough. For + * non-string type options, av_opt_set() will parse the string according to the + * option type. + * + * Similarly av_opt_get() will read any option type and convert it to a string + * which will be returned. Do not forget that the string is allocated, so you + * have to free it with av_free(). + * + * In some cases it may be more convenient to put all options into an + * AVDictionary and call av_opt_set_dict() on it. A specific case of this + * are the format/codec open functions in lavf/lavc which take a dictionary + * filled with option as a parameter. This allows to set some options + * that cannot be set otherwise, since e.g. the input file format is not known + * before the file is actually opened. + *) + +type + TAVOptionType = ( + AV_OPT_TYPE_FLAGS, + AV_OPT_TYPE_INT, + AV_OPT_TYPE_INT64, + AV_OPT_TYPE_DOUBLE, + AV_OPT_TYPE_FLOAT, + AV_OPT_TYPE_STRING, + AV_OPT_TYPE_RATIONAL, + AV_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length + AV_OPT_TYPE_CONST = 128 +{$IFDEF FF_API_OLD_AVOPTIONS} + FF_OPT_TYPE_FLAGS, + FF_OPT_TYPE_INT, + FF_OPT_TYPE_INT64, + FF_OPT_TYPE_DOUBLE, + FF_OPT_TYPE_FLOAT, + FF_OPT_TYPE_STRING, + FF_OPT_TYPE_RATIONAL, + FF_OPT_TYPE_BINARY, ///< offset must point to a pointer immediately followed by an int for the length + FF_OPT_TYPE_CONST = 128 +{$ENDIF} + ); + +const + AV_OPT_FLAG_ENCODING_PARAM = 1; ///< a generic parameter which can be set by the user for muxing or encoding + AV_OPT_FLAG_DECODING_PARAM = 2; ///< a generic parameter which can be set by the user for demuxing or decoding + AV_OPT_FLAG_METADATA = 4; ///< some data extracted or inserted into the file like title, comment, ... + AV_OPT_FLAG_AUDIO_PARAM = 8; + AV_OPT_FLAG_VIDEO_PARAM = 16; + AV_OPT_FLAG_SUBTITLE_PARAM = 32; + +type + (** + * AVOption + *) + PAVOption = ^TAVOption; + TAVOption = record + name: {const} PAnsiChar; + + (** + * short English help text + * @todo What about other languages? + *) + help: {const} PAnsiChar; + + (** + * The offset relative to the context structure where the option + * value is stored. It should be 0 for named constants. + *) + offset: cint; + type_: TAVOptionType; + + (** + * the default value for scalar options + *) + default_val: record + case cint of + 0: (dbl: cdouble); + 1: (str: PAnsiChar); + (* TODO those are unused now *) + 2: (i64: cint64); + 3: (q: TAVRational); + end; + min: cdouble; ///< minimum valid value for the option + max: cdouble; ///< maximum valid value for the option + + flags: cint; +//FIXME think about enc-audio, ... style flags + + (** + * The logical unit to which the option belongs. Non-constant + * options and corresponding named constants share the same + * unit. May be NULL. + *) + unit_: {const} PAnsiChar; + end; + +{$IFDEF FF_API_FIND_OPT} +(** + * Look for an option in obj. Look only for the options which + * have the flags set as specified in mask and flags (that is, + * for which it is the case that opt->flags & mask == flags). + * + * @param[in] obj a pointer to a struct whose first element is a + * pointer to an AVClass + * @param[in] name the name of the option to look for + * @param[in] unit the unit of the option to look for, or any if NULL + * @return a pointer to the option found, or NULL if no option + * has been found + *) +function av_find_opt(obj: Pointer; {const} name: {const} PAnsiChar; {const} unit_: PAnsiChar; mask: cint; flags: cint): {const} PAVOption; + cdecl; external av__util; deprecated; +{$ENDIF} + +{$IFDEF FF_API_OLD_AVOPTIONS} +(** + * 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. 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[out] o_out if non-NULL put here a pointer to the AVOption + * found + * @param alloc this parameter is currently ignored + * @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 + *) +function av_set_string3(obj: Pointer; name: {const} PAnsiChar; val: {const} PAnsiChar; alloc: cint; out o_out: {const} PAVOption): cint; + cdecl; external av__util; deprecated; + +function av_set_double(obj: pointer; name: {const} PAnsiChar; n: cdouble): PAVOption; + cdecl; external av__util; deprecated; +function av_set_q(obj: pointer; name: {const} PAnsiChar; n: TAVRational): PAVOption; + cdecl; external av__util; deprecated; +function av_set_int(obj: pointer; name: {const} PAnsiChar; n: cint64): PAVOption; + cdecl; external av__util; deprecated; +function av_get_double(obj: pointer; name: {const} PAnsiChar; var o_out: {const} PAVOption): cdouble; + cdecl; external av__util; deprecated; +function av_get_q(obj: pointer; name: {const} PAnsiChar; var o_out: {const} PAVOption): TAVRational; + cdecl; external av__util; deprecated; +function av_get_int(obj: pointer; name: {const} PAnsiChar; var o_out: {const} PAVOption): cint64; + cdecl; external av__util; deprecated; +function av_get_string(obj: pointer; name: {const} PAnsiChar; var o_out: {const} PAVOption; buf: PAnsiChar; buf_len: cint): PAnsiChar; + cdecl; external av__util; deprecated; +function av_next_option(obj: pointer; last: {const} PAVOption): PAVOption; + cdecl; external av__util; deprecated; +{$ENDIF} + +(** + * Show the obj options. + * + * @param req_flags requested flags for the options to show. Show only the + * options for which it is opt->flags & req_flags. + * @param rej_flags rejected flags for the options to show. Show only the + * options for which it is !(opt->flags & req_flags). + * @param av_log_obj log context to use for showing the options + *) +function av_opt_show2(obj: pointer; av_log_obj: pointer; req_flags: cint; rej_flags: cint): cint; + cdecl; external av__util; + +(** + * Set the values of all AVOption fields to their default values. + * + * @param s an AVOption-enabled struct (its first member must be a pointer to AVClass) + *) +procedure av_opt_set_defaults(s: pointer); + cdecl; external av__util; + +{$IFDEF FF_API_OLD_AVOPTIONS} +procedure av_opt_set_defaults2(s: Pointer; mask: cint; flags: cint); + cdecl; external av__util; deprecated; +{$ENDIF} + +(** + * Parse the key/value pairs list in opts. For each key/value pair + * found, stores the value in the field in ctx that is named like the + * key. ctx must be an AVClass context, storing is done using + * AVOptions. + * + * @param opts options string to parse, may be NULL + * @param key_val_sep a 0-terminated list of characters used to + * separate key from value + * @param pairs_sep a 0-terminated list of characters used to separate + * two pairs from each other + * @return the number of successfully set key/value pairs, or a negative + * value corresponding to an AVERROR code in case of error: + * AVERROR(EINVAL) if opts cannot be parsed, + * the error code issued by av_set_string3() if a key/value pair + * cannot be set +*) +function av_set_options_string(ctx: pointer; opts: {const} PAnsiChar; + key_val_sep: {const} PAnsiChar; pairs_sep: {const} PAnsiChar): cint; + cdecl; external av__util; + +(** + * Free all string and binary options in obj. + *) +procedure av_opt_free(obj: pointer); + cdecl; external av__util; + +(** + * 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. + *) +function av_opt_flag_is_set(obj: pointer; field_name: {const} PAnsiChar; flag_name: {const} PAnsiChar): cint; + cdecl; external av__util; + +(** + * 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() + *) +function av_opt_set_dict(obj: pointer; var options: PAVDictionary): cint; + cdecl; external av__util; + +(** + * @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. + *) +function av_opt_eval_flags (obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; flags_out: Pcint): cint; + cdecl; external av__util; +function av_opt_eval_int (obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; int_out: Pcint): cint; + cdecl; external av__util; +function av_opt_eval_int64 (obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; int64_out: Pint64): cint; + cdecl; external av__util; +function av_opt_eval_float (obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; float_out: Pcfloat): cint; + cdecl; external av__util; +function av_opt_eval_double(obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; double_out: Pcdouble): cint; + cdecl; external av__util; +function av_opt_eval_q (obj: pointer; o: {const} PAVOption; {const} val: PAnsiChar; q_out: PAVRational): cint; + cdecl; external av__util; +(** + * @} + *) + +const + AV_OPT_SEARCH_CHILDREN = 0001; (**< 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. + *) + AV_OPT_SEARCH_FAKE_OBJ = 0002; + +(** + * 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. + * @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_set_string3(). Use special calls which take an options + * AVDictionary (e.g. avformat_open_input()) to set options found with this + * flag. + *) +function av_opt_find(obj: pointer; name: {const} PAnsiChar; unit_: {const} PAnsiChar; + opt_flags: cint; search_flags: cint): PAVOption; + cdecl; external av__util; + +(** + * 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. + *) +function av_opt_find2(obj: pointer; name: {const} PAnsiChar; unit_: {const} PAnsiChar; + opt_flags: cint; search_flags: cint; target_obj: pointer): PAVOption; + cdecl; external av__util; + +(** + * 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 + *) +function av_opt_next(obj: pointer; prev: {const} PAVOption): PAVOption; + cdecl; external av__util; + +(** + * 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 + *) +procedure av_opt_child_next(obj: pointer; prev: pointer); + cdecl; external av__util; + +(** + * 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 + *) +(* +function av_opt_child_class_next(parent: {const} PAVClass; prev: {const} PAVClass): PAVClass; + cdecl; external av__util; +*) + +(** + * @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 + *) +function av_opt_set (obj: pointer; name: {const} PAnsiChar; val: {const} PAnsiChar; search_flags: cint): cint; + cdecl; external av__util; +function av_opt_set_int (obj: pointer; name: {const} PAnsiChar; val: cint64; search_flags: cint): cint; + cdecl; external av__util; +function av_opt_set_double(obj: pointer; name: {const} PAnsiChar; val: cdouble; search_flags: cint): cint; + cdecl; external av__util; +function av_opt_set_q (obj: pointer; name: {const} PAnsiChar; val: PAVRational; search_flags: cint): cint; + cdecl; external av__util; +(** + * @} + *) + +(** + * @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 av_malloc()ed and must be av_free()ed by the caller + *) +function av_opt_get (obj: pointer; name: {const} PAnsiChar; search_flags: cint; out_val: Pcuint8): cint; + cdecl; external av__util; +function av_opt_get_int (obj: pointer; name: {const} PAnsiChar; search_flags: cint; out_val: Pcint64): cint; + cdecl; external av__util; +function av_opt_get_double(obj: pointer; name: {const} PAnsiChar; search_flags: cint; out_val: Pcdouble): cint; + cdecl; external av__util; +function av_opt_get_q (obj: pointer; name: {const} PAnsiChar; search_flags: cint; var out_val: PAVRational): cint; + cdecl; external av__util; +(** + * @} + *) + +(** + * 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. + *) +(* +procedure av_opt_ptr(avclass: {const} PAVClass; obj: pointer; name: {const} PAnsiChar); + cdecl; external av__util; +*) + +(** + * @} + *) + +implementation + +end.
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