Need some help with "libvlc_media_new_callbacks"

[fabsther]

Hi,

I manage to create a video using these callbacks, by using an sout parameter.
I 've got some questions :
-How I configure the format / codecs of data i give to read callback ?
-Can I put both video and audio stream in the same time ? Or should I assemble two media from callbacks ?

Thanks for your time.

fabsther