[AG-TECH] AGN Audio Lip Sync

[Colin Perkins]

On Tuesday, Sep 16, 2003, at 19:36 Europe/London, Randy Groves wrote:
> How much, if any, would the local machine time vs. the remote nodes' 
> time have to do with this?  Would it help to make sure that NTP is 
> running and appropriately syncing the system time?

I haven't looked at the AccessGrid versions of vic and rat recently, but
unless there have been significant changes, they don't support lip-sync.
Any synchronisation you see is coincidental, and occurs because the 
media
streams follow the same network path, and so arrive at approximately the
same time.

The drift over time likely happens because the audio hardware on one 
host
runs at a slightly different rate to that on the other (this is a really
common problem with PC sound cards). Rat has code to compensate, but it
doesn't always work. Enabling silence suppression in rat will likely 
help.
NTP synchronisation will not.

-- 
Colin Perkins
http://csperkins.org/