Audio Video synchronization issues

Hi,
I have a video application that I am building - and
previously I used FMS and TCP connections for video. Now expecting
the latency to be much lesser with UDP, I implemented UDP in my
application and stratus as the RTMFP capable server. I used the
sample video phone application's tutorial do a simple sendStream
and receiveStream for video.
However, unlike the hosted sample application itself, my
audio and video are completely out of synchronization - about 4
secs!! I tried to look at the sample code to see if there were any
special settings that were made. I could not find any.
My questions:
1. Did Adobe make any special tweaks in their hosted sample
application? If so, what are they?
2. Are there any known synchronization issues with using
RTMFP connections for video?
3. Does anyone else also face audio video synchronization
issues?
4. If none of the above is true, what do you think my
mistakes are? Please let me know if I need to add more information
to answer this question.
Thanks in advance.
Rohan

with RTMFP, video and audio can go out of sync if the data
rate of your stream exceeds your network capacity. video is
currently sent with 100% reliability, so once it's queued for
transmission, it's going to be sent (eventually). video is lower
priority than audio, though, so your audio data gets first dibs on
your network capacity. if the video stream's data rate is higher
than what fits in your network (after audio), the video data will
back up until its send buffer is filled, and new camera frames will
stop getting captured. in the steady state, this can look like a
multi-second offset between the video and audio.
try turning your video rate/quality down so that it fits in
your network capacity. video and audio should stay in sync.
with RTMP, there's one network transmission buffer (TCP's)
for all of the parts of your stream (audio & video). when you
have insufficient network bandwidth, the TCP buffer will eventually
fill up and video frames will stop being captured to compensate. so
while audio and video might remain in sync, the total end-to-end
latency will go up. when using RTMFP, the audio and video have
independent transmission buffers, so in cases of insufficient
network resources, the higher-priority audio should remain more
timely but video may fall behind.
-mike

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rate of your stream exceeds your network capacity. video is
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Ok so I'm a bit of a dummy. This issue has been really bugging me so I decided to try a lens cleaner to see if it would help. It didn't unfortunately. I then uninstalled the drive and rebooted rather than scanning for hardware changes. This improved things a bit-I was able to play a cd normally in Media Player but nothing else. I checked the IDE controllers again and the secondary channel this time was running in PIO mode. I uninstalled the sencondary controller, rebooted and voila! The controller reinstalled, is now running in Ultra DMA Mode 2, DVDs and CDs now play fine. Either the lens was dirty and causing time out issues while reading discs which caused the change to PIO or I just missed it when I first checked. Either way, thanks for the help.

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