mplayer can't read from streamripper relay

Question

To use the same bandwidth for ripping and playing a stream I start a relay when ripping with streamripper :

$ streamripper -r link2stream

And to play it :

$ vlc http://localhost:8000

With vlc this works fine, but I want to use mplayer which doesn't work :

$ mplayer http://localhost:8000

Playing http://localhost:8000.
Resolving localhost for AF_INET...
Connecting to server localhost[127.0.0.1]: 8000...

Name   : ...
Website: ...
Cache size set to 320 KBytes
Cache fill: 19.31% (63270 bytes)   

Exiting... (End of file