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
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