Looks up the GStreamer tag for an ID3v2 user tag (e.g. description in TXXX frame or owner in UFID frame).
the type of ID3v2 user tag (e.g. "TXXX" or "UDIF")
ID3v2 user tag to convert to GStreamer tag
The corresponding GStreamer tag or NULL if none exists.
Looks up the GStreamer tag for an ID3v2 user tag (e.g. description in TXXX frame or owner in UFID frame).