How can I treat audio 3gp files?

[tmak]

Thank you for developing this great software!
Now I have a problem.
I have a lot of .3gp files that contains only audio.
(They are created by ripping CD with x-appli, a music software provided for my android phone)
To play them on my player (SONY BRAVIA KDL-40v5), I want PMS to transcode into PCM.
Unfortunately, currently PMS considers any 3gp file as a video file, and try to use MEncoder for transcoding,
which fails due to the lack of video stream.
Are there any good way to make PMS recognize these 3gp files as audio?
Currently I don't have any video 3gp files, so a dirty solution (that breaks support for video 3gp) is also welcome.