[Icecast] matrox rt.x100

Leo Currie leo.currie at strath.ac.uk
Wed Dec 14 16:52:31 PST 2005


Balint Jacint wrote:
> I got a Matrox RT.X100 Pro capture card to make a live video streaming 
> with it. The concert to be streamed will be on Saturday...
> I have a Linux-based server running Icecast 2.3, so I need to make this 
> computer with the Matrox card to work with the Icecast server. I'd 
> prefer Ogg Theora.
> Unfortunately there's no Linux support for this card, so the only choice 
> I have is Windows XP.
> Do you have any idea, how to move on? Has anyone ever faced a problem 
> like this? Or is this card "too good" for live streaming...?
> I've never ever in my life had anything to do with video, so I feel a 
> little lost here...

This ought to be possible, but I've spent a few hours trying without 
much success.

VLC[1] for Windows should in theory be able to do this (assuming your 
capture card is DirectShow capable, which it probably is) but in 
practise it seems that none of the components required (theora encoder, 
vorbis encoder, ogg muxer and libshout output) work properly on the 
windows version.  In fact, attempting to encode even static files to 
Theora in VLC seems to fail more often than it succeeds.

I also tried to make VLC output the ogg stream to STDOUT, and pipe this 
into Ezstream[2], but that failed as well - I'm not convinced it was 
encoding at all.

One thing that did work (sort of) was using Graphedit[3] and Ezstream 
with the DirectShow ogg filters[4].
A graph was created similar to that shown on the example page[5], except 
the source was my webcam and soundcard. The graph was started and then 
Ezstream was launched which read the file that graphedit was creating.
It worked, but the sound was hopelessly out of sync, the framerate 
erratic, and ezstream reached the eof too quickly and so re-started it.

If there were a DirectShow Ogg mux'er which supported outputting to a 
named pipe, and if Ezstream supported reading from named pipes on 
windows, this might actually work (?)

Anyway, all this waffle doesn't help you stream video! The easy solution 
is to go out and buy the cheapest V4L compatable video capture card 
(e.g. a BT878 based card) which will certainly work in Linux.
If you must stream using the hardware you have, it might be possible to 
use VLC to relay captured video to a linux machine, which could then 
re-encode to theora. I haven't tried this.
Another option is to stream in a different format - Icecast currently 
supports NSV (if you use the SHOUTcast compatibilty mode!) and there are 
  available tools[6] to encode live video to NSV on windows.


Good luck!

Leo


[1] http://www.videolan.org/
[2] http://www.icecast.org/ezstream.php
[3] Part of the DirectX SDK - http://msdn.microsoft.com/directx/sdk/
[4] http://www.illiminable.com/ogg/
[5] http://www.illiminable.com/ogg/enc_theora_graphedit.html
[6] http://www.scvi.net/check.htm


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