func (p *Comment) Add(comment string) {
cComment := C.CString(comment)
C.vorbis_comment_add((*C.vorbis_comment)(p), cComment)
C.free(unsafe.Pointer(cComment))
}
// CommentAdd function as declared in https://xiph.org/vorbis/doc/libvorbis/vorbis_comment_add.html
func CommentAdd(vc *Comment, comment string) {
cvc, _ := vc.PassRef()
ccomment, _ := unpackPCharString(comment)
C.vorbis_comment_add(cvc, ccomment)
}