Parse the format query and retrieve the @nth format from it into @format. If the list contains less elements than @nth, @format will be set to GST_FORMAT_UNDEFINED.
the nth format to retrieve.
a pointer to store the nth format
See Implementation
Parse the format query and retrieve the @nth format from it into @format. If the list contains less elements than @nth, @format will be set to GST_FORMAT_UNDEFINED.