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Multicast blips

Posted: 04 May 2015 23:41
by GezusK
We've set up a paging system in our school system that uses multicast from a paging server to the ceiling speakers. Some of the rooms don't have speakers yet, or won't be getting speakers. We discovered that VLC will receive the stream, and works pretty well for the most part. The issue we're having is after receiving a broadcast, VLC will play the last second of the last received broadcast, every couple of minutes. For instance, after an announcement is made, the last sound is the hand set being hung up. So the rest of the day, a click will be heard...that is, until the bell system starts it's broadcasts. Then it starts repeating that sound every couple of minutes. Only VLC is doing this, nothing happens on the ceiling speakers. I've reduced the buffer, which does shorten the audio that it repeats, but it's still there.

This is the address we're playing:
rtp://@239.168.3.10:11000
Currently testing with a 10ms buffer...which appears to work well, other than the blips after broadcast. I did test 0ms, but the audio didn't come through clear.

I tried choosing different audio devices (default, DirectSound, WavOut), no luck. My Googling hasn't turned up anything, which is amazing, considering it happens on all our systems, with different setups.

I'm looking for some suggesting as to what to try next. I really like VLC, and it would be perfect to set it to run as a service and receive these broadcasts. I'm also open to other software suggestions for this purpose. Every system will have 3 multicasts streams that it listens for (Emergency, All, and Grade specific).

Thanks to anyone who can help.

Re: Multicast blips

Posted: 05 May 2015 11:40
by Jean-Baptiste Kempf
VLC version?

Re: Multicast blips

Posted: 05 May 2015 14:57
by GezusK
Currently using 2.2.

Re: Multicast blips

Posted: 05 May 2015 15:02
by Jean-Baptiste Kempf
2.2.1 32bits under Windows 7 ?

Re: Multicast blips

Posted: 05 May 2015 15:10
by GezusK
Sorry, 2.2.0 64bit under Win7 on my system. And 2.2.0 32bit on Windows 7 and XP for other systems.

Re: Multicast blips

Posted: 05 May 2015 15:33
by Jean-Baptiste Kempf
Try 2.2.1, please.

Re: Multicast blips

Posted: 05 May 2015 21:01
by GezusK
Just tried 2.2.1 64bit on my Windows 7 system. I started listening to the multicast stream I listed above. I then started streaming using another instance of VLC (an Adele track). After stopping the stream, the player would play the last second of audio every couple of minutes until I stopped it. So, same issue, just used a different source.

Re: Multicast blips

Posted: 05 May 2015 22:29
by Jean-Baptiste Kempf
Did you try waveout in 2.2.1, (after restarting VLC) ?

Re: Multicast blips

Posted: 05 May 2015 23:19
by GezusK
Looks like that worked. I was looking over the command line to set it to Waveout.
I found:
--waveout-audio-device=

I'm trying to test it, but it doesn't appear to be doing anything. I started up VLC, set audio output to DirectX. Closed it. I then ran VLC via command line, with the above switch set to default:
--waveout-audio-device=default

I checked the output, and it's still set to DirectX. So did I use the switch wrong, or does the GUI not reflect the change?

Thanks so much for your help.

Re: Multicast blips

Posted: 06 May 2015 10:18
by RĂ©mi Denis-Courmont
--aout=waveout

Re: Multicast blips

Posted: 06 May 2015 15:06
by GezusK
Thanks.
Ok, one last question...as I mentioned, we'll have 3 streams to listen to. Is it possible for one instance of VLC to listen to 3 multicast streams at once, or will I need to stick with running a VLC instance for each stream?