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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=239055619-07062002>I am
assuming that the key for lip synch is that rat calculates the end-to-end delay
between encoding and final playback, and then rat sends rtp.source.playout
messages to the local vic. NTP is needed to get accurate time differences. Vic
can then adjust it's playback to match rat. </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=239055619-07062002></SPAN></FONT><FONT face=Arial color=#0000ff
size=2><SPAN class=239055619-07062002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=239055619-07062002>This
actually works to a point - vic gets the rtp.source.playout message, but then
can't figure out who the sender is! Vic looks through the cname_hash_table,
which is empty. Rat never sent an rtp.source.cname message to any vic (it does
send them to other rat processes though).</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=239055619-07062002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=239055619-07062002>I
tried a hack where vic sends an rtp.query message to all rats if it gets an
unknown rtp.source.playout message, which is a little too late, and rat starts
getting assertion failures soon after.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=239055619-07062002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=239055619-07062002>I'm
not sure where the breakdown occurred. Should rat broadcast cname messages to
all vics on occasion? Should vic ask for cname at a better
time?</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=239055619-07062002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=239055619-07062002>Thanks!</SPAN></FONT></DIV>
<DIV><FONT><SPAN class=239055619-07062002></SPAN></FONT><FONT face=Arial><FONT
color=#0000ff><FONT size=2> <SPAN class=239055619-07062002>- Derek
White</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=239055619-07062002></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=239055619-07062002></SPAN><FONT><SPAN class=239055619-07062002>ps. This is
with rat 4.2.16 built from cvs source. I spent a day trying to get vic
2.8.ucl-1.1.3-AG to talk to rat 4.2.21, which is hopeless. The newer mbus code
does encryption and authentication in the opposite order, and over a different
part of the message! They silently refuse to talk at
all.</SPAN></FONT></FONT></FONT></FONT></DIV>
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<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B> Nolan, Kevin
[NCSUS] [mailto:knolan@ncsus.jnj.com] <BR><B>Sent:</B> Friday, May 31, 2002
1:12 PM<BR><B>To:</B> ag-tech@accessgrid.org<BR><B>Subject:</B> [AG-TECH]
Audio losses synch<BR><BR></FONT></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I have a question
-</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">We seem to lose synch with audio
and video during sessions. After several hours of being up, the AG
machines seem to fall into a 4 second audio delay and not synchronize with
video. Is there a way to avoid this?</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><B><I><FONT face="Times New Roman" size=3><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 12pt; FONT-STYLE: italic">Kevin</SPAN></FONT></I></B></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P></DIV></BLOCKQUOTE></BODY></HTML>