[streaming] speex or ulaw or alaw over rtp

[Edgar]

  Hi all, i'm tryin to transcode a wav file to speex or g711 formats and 
send them through multicast over rtp protocol. However i get the message 
from vlc that only the TS/PS muxers are supported for streaming using 
RTP, but I read in videolan.org homepage that alaw/ulaw and speex are 
suported for rtp streaming too, the problem is that if I don't specify 
the muxer, when I try to recieve the stream I get nothing. When I 
transcode to mp2 or mpga and use TS muxer everything works fine. How can 
I use the speex or ulaw/alaw over rtp? thanks