Hi,
I have a problem I’m trying to solve for two days now, with no success. (please do not be discouraged by the size of this post 
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- A typical live webcam based flash meeting application that also supports recording each stream: we’ve got customer complaints there is some serious de-sync between audio and video (about a second) for each participant’s live stream. The customer says this didn’t happen before, but I wasn’t able to verify this; I tried various milestone versions of the application but all had this de-sync - so I’m not sure about this. I never experienced this problem, but it might be platform related (see below)
Some Info:
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Wowza saves the streams as FLV, the video codec is the default codec used by Flash when capturing webcam, and the audio codec is Speex.
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The recorded stream does not have this problem, so it only appears to be live related.
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We did some tests, 2 meeting attendees running Windows with Chrome/Firefox and one running Mac OS with Safari (latests Flash plugin versions for all) - first two had the A/V sync problem, meaning they each saw the others’ live stream out of sync, the mac user did not have this problem, and all participants’ live streams played correctly. Without making any server or network changes, I moved them one at a time from Windows to Mac OS and they stopped having the A/V sync problem as they switched platform. In the end the meeting consisted of 3 live streams, all from Mac OS clients, none having the A/V sync issues. So, the few times we did that test it seemed to be a platform issue, but I wouldn’t want to steer towards that conclusion yet since it usually means “dead end” when going there, maybe there’s something else I’m missing.
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All video objects had smoothing enabled by default since the beginning of the development, but turning it off seemed to not help at all;
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the two initial Windows clients were running off the same local network, my machine (at the time the only Mac client) was running off a different network in another city; the Wowza server instance I believe is hosted on Amazon.
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I wouldn’t blame this on the server, because Mac clients did not have the problem; I wouldn’t think bandwidth was an issue either since this application is not particularly bandwidth heavy with 2-3 attendees, and again once clients switched on Mac it worked fine;
Did anyone else experience A/V sync issues with a similar scenario? (webcam group video chat to Wowza as FLV).
What other steps could I take to find the cause and maybe force a solution even if at the cost of audio or video quality? (at least temporarily).
I would very much appreciate any help/hints/questions on this…
Thank you!
Cristi
