[AG-TECH] No audio when running VLC and RAT simultaneously w/ Linux(CentOS)??

[Douglas Kosovic]

Hi Andrew,

Try using ALSA instead of OSS in RAT, as I think OSS requires exclusive
access to the audio device.


Doug

> -----Original Message-----
> From: ag-tech-bounces at lists.mcs.anl.gov [mailto:ag-tech-
> bounces at lists.mcs.anl.gov] On Behalf Of Andrew Leahy
> Sent: Wednesday, 9 September 2009 1:30 PM
> To: ag-tech
> Subject: [AG-TECH] No audio when running VLC and RAT simultaneously w/
> Linux(CentOS)??
> 
> Hi, we seem to have contention issues with the audio devices when
> using RAT and VLC (VideoLan Client).
> 
> Scenario - an academic wants to play a video file (MPEG) during his AG
> session and have it appear at the remote sites.
> 
> Our first idea was to use VLC on all the AG display machines (running
> VenueClient/RAT/VIC).
> Audio coming out of the local display machines should be treated the
> same as audio coming from remote AG sites, which should play into the
> room, be echo-cancelled by our ClearOne units before going into
> Line-In, so in theory it shouldn't end up echo'ing back at the remote
> sites.
> 
> When we stream the video using VLC (either in multicast or
> point-to-point) without RAT running, the video & audio plays fine.
> 
> However, if RAT is running, the video plays but there's no audio.
> Not "no audio" like it's being echo-cancelled, it's "no audio" as
> though VLC isn't even trying.
> I suspect RAT is "locking" the Linux audio device?
> I can probably dig up error messages for this, unfortunately I'm
> remote from the machines right now.
> 
> Host machines - Linux mix of CentOS5.3  and Fedora Core 8. AGtk 3.1
> 
> Does anyone have suggestions for working around this?
> If it "should work" we'll keep trying harder!
> 
> At the moment, it looks like we'll have to use another machine in the
> AG rooms (connected to the room audio) and make sure RAT is muted so
> we don't cause echo.
> 
> Cheers, Andrew
> 
> IT Research Support / University of Western Sydney
> 
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