/* * AVOptions * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> * * This file is part of Libav. * * Libav 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 2.1 of the License, or (at your option) any later version. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_OPT_H #define AVUTIL_OPT_H /** * @file * AVOptions */ #include "rational.h" #include "avutil.h" enum AVOptionType{ 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, }; /** * AVOption */ typedef struct AVOption { const char *name; /** * short English help text * @todo What about other languages? */ const char *help; /** * The offset relative to the context structure where the option * value is stored. It should be 0 for named constants. */ int offset; enum AVOptionType type; /** * the default value for scalar options */ union { double dbl; const char *str; /* TODO those are unused now */ int64_t i64; AVRational q; } default_val; double min; ///< minimum valid value for the option double max; ///< maximum valid value for the option int flags; #define AV_OPT_FLAG_ENCODING_PARAM 1 ///< a generic parameter which can be set by the user for muxing or encoding #define AV_OPT_FLAG_DECODING_PARAM 2 ///< a generic parameter which can be set by the user for demuxing or decoding #define AV_OPT_FLAG_METADATA 4 ///< some data extracted or inserted into the file like title, comment, ... #define AV_OPT_FLAG_AUDIO_PARAM 8 #define AV_OPT_FLAG_VIDEO_PARAM 16 #define AV_OPT_FLAG_SUBTITLE_PARAM 32 //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. */ const char *unit; } AVOption; /** * 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 */ const AVOption *av_find_opt(void *obj, const char *name, const char *unit, int mask, int flags); /** * 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 when 1 then the old value will be av_freed() and the * new av_strduped() * when 0 then no av_free() nor av_strdup() will be used * @return 0 if the value has been set, or an AVERROR code in case of * error: * AVERROR(ENOENT) if no matching option exists * AVERROR(ERANGE) if the value is out of range * AVERROR(EINVAL) if the value is not valid */ int av_set_string3(void *obj, const char *name, const char *val, int alloc, const AVOption **o_out); const AVOption *av_set_double(void *obj, const char *name, double n); const AVOption *av_set_q(void *obj, const char *name, AVRational n); const AVOption *av_set_int(void *obj, const char *name, int64_t n); double av_get_double(void *obj, const char *name, const AVOption **o_out); AVRational av_get_q(void *obj, const char *name, const AVOption **o_out); int64_t av_get_int(void *obj, const char *name, const AVOption **o_out); const char *av_get_string(void *obj, const char *name, const AVOption **o_out, char *buf, int buf_len); const AVOption *av_next_option(void *obj, const AVOption *last); /** * 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 */ int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags); void av_opt_set_defaults(void *s); void av_opt_set_defaults2(void *s, int mask, int flags); /** * 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 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 */ int av_set_options_string(void *ctx, const char *opts, const char *key_val_sep, const char *pairs_sep); /** * Free all string and binary options 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); #endif /* AVUTIL_OPT_H */