an extended comment string, see #GST_TAG_EXTENDED_COMMENT
return location for the comment description key, or NULL
return location for the comment ISO-639 language code, or NULL
return location for the actual comment string, or NULL
whether to fail if strings are not in key=value form
TRUE if the string could be parsed, otherwise FALSE
Convenience function to parse a GST_TAG_EXTENDED_COMMENT string and separate it into its components.
If successful, key, lang and/or value will be set to newly allocated strings that you need to free with glib.global.gfree when done. key and lang may also be set to NULL by this function if there is no key or no language code in the extended comment string.