nlamartina wrote on 3/27/2001, 11:24 AM

Are you experiencing loss of synchronization during
playback of any video? Or just your creations/captures? If
this is a post production problem, here's a possible way to
fix this (this is a copy of post I wrote for someone with a
similar problem):

"What you're [possibly] experiencing is known as NTSC time
lag. Thanks to [VegasVideo]'s advanced interface, it's very
easy correct. Let me explain first why this happens (the
are multiple reasons, but here are a few possible ones):

- The NTSC standard calls for video and audio to be
synchronized at 30 frames per second (fps).
- In order to prevent cross-talk when transmitting AV
signals over an antenna, it was decided to offset the video
stream by just a hair, so the video runs at 29.97 fps, and
audio at 30 fps
- When a computer system renders frames, it does things
mathematically, and literally renders your video at 29.97
fps, and your audio at 30 fps (unless it knows better).
This causes the video to get ahead of the audio. The longer
your clip, the worse it gets. This timecode is
called "SMPTE non-drop".
- VideoFactory allows for "SMPTE drop" timecode, which
buffers the video off-set with an occasional blank frame to
keep the video in synch.

Here are some tips you can use to keep the synch together:

1. Set your project default timecode to "SMPTE drop"
in "project properties".
2. Avoid rendering your final copy at a lower framerate
than the material present in your project, ie, using
material that is 25 fps and rendering at 15 fps. Try to be
consistant as possible.
3. If the recorded/captured material in out of synch, first
place it in your project. Hold down your control key. Left
click on the end of the audio stream and drag it inward
until the audio lines up properly (preview to check).
Generally, use 1.2 second for every 20 minutes.
4. Go to this hyperlink for extended information on SMPTE

I hope this helps. The problem you describe is something I
battled with for almost a year. It sometimes takes practice
to avoid, but keep trying, and I'm certain you'll get the
hang of it."

There you go. Give that a shot and let me know how it turns
out. If you are experiencing this problem across the board,
it's most likely an internal synch problem. Sometimes, when
AV material is being processed/played from the physical
memory, and then something needs to be suddenly processed
that diverts your processor's attention, like a pop-up
window or help dialogue, the marker (and consequently
video/audio) synch will be lost. Make sure you've closed
all uneeded programs when working with Vegas and that your
machine is up to par with system specs.

Hope this helps,
Nick LaMartina
videocrusher wrote on 3/27/2001, 12:23 PM
Thanks for the insight, Here are some facts, the actual avi
is captured with a Osprey 500 Pro card. the uncompressed
AVI works great. Only on import in to vegas does the
problem accure.

This problem goes away once Service Pack One is removed
from the system, Before I spend hours on what SP-1 Update
causes this issue I thought I would ask Around.

I find having to adjust time A/V time line to achive
lipsync totaly unacceptable.

Thank you very much for your help. I will post my findings

teomorell wrote on 3/27/2001, 2:05 PM
How long is the your video?
Can you tell the lag amount between video and audio in seg
by the end of the video?

videocrusher wrote on 3/28/2001, 2:31 PM
The video seems to be ahead of the audio about 4 frames no
matter what size the file. Tryed Directx 8a update no help
the only thing that corrects issue is to deinstall Service
Pack 1-

Thanx, matt
SonyEPM wrote on 3/28/2001, 4:01 PM
Is this occuring:

a)only in files rendered in Vegas

b)only in the Vegas preview window

c)only on an external monitor

or a combination?
videocrusher wrote on 3/30/2001, 1:24 PM
Capture card Osprey 500 pro REV D app/ver 1.04

Shows in preview window in application (vegas), and will
encode with lipsync off
videocrusher wrote on 3/30/2001, 1:26 PM
Yes only a vegas issue, Adobe is fine! and Windows media
encoder is fine.