Synchronizing 2 simultainious videos

Question

Our current project needs to simultaneously present two
videos and keep them synchronized. We are using ActionScript 3 and
we use one controller (play, pause, stop, hSlider). Our controller
is able to start, pause and stop the two videos just fine. They
start simultaneously, but as they are playing, the two videos fall
out of sync.
There does not seem to be anything systematic about the loss
of sync. That is, sometimes video 1 gets ahead, other times video 2
gets ahead. This loss of sync can be anywhere from 1 frame of video
up to more than a full second of video.
Both videos are running at 15 FPS and have the same key
frames. (In fact, the loss of sync occurs even when we are running
the identical video in the two VideoDisplays.)
We will appreciate any suggestions about keeping these two
videos synchronized while playing.

Answer 1

There is no practical way to synch two independent
movieClips, let alone
two video clips. You are decompressing the files at runtime.
The amount
of work that the computer has to do is directly proportional
to the
amount of data that is in the files.
Using a third party compressor, like Squeeze, you can set a
data rate
for the finished, compressed file. With a low enough data
rate, you can
usually get reliable playback of at least one .swf video or
.flv video
file. This is the same methodology that's used for
compressing real
video files like Quicktime.
When you add a second file to be played simultaneously, you
are more
than doubling the amount of work to be done.
With judicious use of a third party compressor you may be
able to get
acceptable playback on most computers, but there's no way to
guarantee
consistent results.
If there is no sound in these videos, you might be able to
lock step
them by playing each frame by frame, but that may make the
process worse.
One sure solution is to re-edit the two original files into
one video
and then save that out as an .swf or .flv.