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Multicast, RTSP and SDP generation issues

Posted: 10 Oct 2008 09:50
by paquirrin
Hi everybody! I'm trying to setup a multicast stream using VLC on Linux and generate an SDP file in order to provide it to the clients via RTSP. The problem is the following:

If I do something like this:

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vlc -vvv -L file:///path/to/file.extension --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128,deinterlace}:rtp{mux=ts,dst=239.255.12.42,port=7374,sdp=file:///path/to/file.sdp,name="TestStream"}'
I get a fully working multicast stream (i.e. it can be accessed from a VLC client doing vlc rtp://@IP:PORT. BUT no sdp is created and apparently no error messages shown.

In the other hand if I try to remove the mux field:

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vlc -vvv -L file:///path/to/file.extension --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128,deinterlace}:rtp{dst=239.255.12.42,port=7374,sdp=file:///path/to/file.sdp,name="TestStream"}'
The sdp is generated but I'm unable to open it (locally), the errors shown are similar to this (I say similar because the last part is in spanish):

09:42:14 Groupsock(-1: 239.255.12.42, 1232, 255): failed to join group: setsockopt(IP_ADD_MEMBERSHIP) error: Invalid file descriptor

The flow is also impossible to open from VLC as client, it is just stuck at prebuffering.

Can anybody help me? Is it possible to generate an SDP and a "proper" multicast flow at the same time? Why is the sdp unable to be opened?

By the way, the main idea of all this is generating the SDP to be accessed via RTSP as some devices (mobile phones) are unable to interact with udp://@ rtp://@ urls. Any alternative to this proposal will also be welcomed. I have read solutions based on generating an SDP file and serving it with Darwin Streaming but this is an unicast solution.

Thank you!

P.S. Sorry for my English.

Re: Multicast, RTSP and SDP generation issues

Posted: 06 Nov 2008 06:20
by an3k
I noticed the same problem,

if mux is specified, dsp file is not genereated. if mux is not specified, dsp file IS generated!

Re: Multicast, RTSP and SDP generation issues

Posted: 06 Nov 2008 20:51
by RĂ©mi Denis-Courmont
Looks like a live555 bug.

Re: Multicast, RTSP and SDP generation issues

Posted: 10 Nov 2008 19:04
by fitzpete
i can confirm this behaviour. Still present in todays 0.9.6 release.
I guess we are screwed...