[AG-TECH] Audio losses synch (more technical questions)

Robert Olson olson at mcs.anl.gov
Mon Jun 10 07:49:13 CDT 2002


We typically don't run with lipsynch activated between rat & vic (reasons 
include the necessity to play with .mbus files to get the synchronization 
to work properly between audio and display machines, the fact that vic's 
synch support is indeed out of synch with the support in rat, and that when 
on a good-quality network, the casual synchronization resulting from 
best-effort transmission results in "good-enough" lipsynch).

All that being said, if you get this working that'd be great, and we should 
look at integrating the fixes.


>At the moment this would not be enough to fix a standard AG node, if audio
>and video sources are from different machines the cnames will not match
>anyway as these are derived from the IP address.

We've had some other discussion lately about changing the AG stuff to 
define CNAMEs on a per-node rather than per-host basis.

>I managed to compile up the AG vic code linked against the most up to date
>UCL common library. (There is some new crypto code that has been
>seperatly added to both development trees but if you delete the files
>from vic the program still links ok)

An aside on why this is there - vic doesn't use the libcommon mechanisms 
for RTP transport (it has its own internal RTP handling code). The crypto 
code that's in libcommon is there in support of rat (and other clients of 
the libcommon RTP library). Vic has analagous crypto code in a module 
conforming to the vic crypto interface.

>  This might be enough to fix this
>problem. It should be as all the mbus code would be from the same
>revision.

Did you see any weirdness with vic built with the latest libcommon? if not, 
we can go ahead and merge the new libcommon in with vic.

Did you use the CVS version, or the latest release version (1.2.8). Ivan 
found some win32 portability problems in the latest CVS version; not sure 
of the state of resolution of those.

--bob
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