* @param m The metadata structure to be parsed. For no metadata, set to NULL.
* @param vendor_string The vendor string to be added into the VorbisComment.
* For no string, set to an empty string.
* @param m The metadata structure to be parsed. For no metadata, set to NULL.
* @param vendor_string The vendor string to be added into the VorbisComment.
* For no string, set to an empty string.