modify/apply on all streams, --sout has the same behavour expect when
starting with a '#'.

 With a starting '#' you can specify a chain of modules, it's still
unstable but a lot more powerfull.
 You have access to duplicate(that duplicate all stream), transcode
(using only ffmpeg), standard/std and es (that apply muxers and access),
and display. You could chain them with ':' and specify options with
{option1=value,option2=value[,...]}.

ex: * to stream and see the stream to udp/ts:ip
 --sout '#duplicate{dst=display,dst=std{access=udp,mux=ts,url=ip}}'
    * to transcode,see and stream
 --sout '#transcode{acodec=mpga}:duplicate{dst=display,dst=std{access=udp,mux=ts,url=ip}}'

 Without a starting '#', the url is converted into '#std{acces=,mux=,url}'
Test and report bugs :)