Posted by Bob on 11/05/05 14:28

On Fri, 4 Nov 2005 17:11:06 -0600, "Ken Maltby"
<kmaltby@sbcglobal.net> wrote:

>> I have this one clip that I cannot get to sync properly no matter what
>> I try, and that includes VideoReDo.

> It is possible that you have a clip that was digitized/captured
>out of lip sync.

The clip is not out of sync until I render it with MF4.

>If that is the case, the video and audio frame
>markers will line up so that it remains out of sync. QuickFix
>is doing its job by properly aligning the markers, if it were a
>matter of the audio& video being out of sync due to dropped
>or purposely discarded frames then QuickFix would have fixed
>the problem. This is all that is needed for 99% of such issues.

The original clip does not require fixing since it is in sync. The
clip I get after rendering with MF4 (I use the "export" facility with
Two Pass rendering), is out of sync.

I have tried to run the original clip thru VideoReDo just to make sure
it is OK and then render it with MF4 - it then becomes out of sync.

I have also run the rendered clip that is out of sync thru VRD and it
does not correct the problem.

> For the few that are digitized out of sync, VideoReDo has a
>feature under the "Tools" tab called "Adjust Audio
>Synchronization ..." Why not give that a try.

I tried that before and could not get it to work in MF4. But this time
I spent more effort because you recommended it. If I play with MF4
carefully I can get it to work. By that I mean saying No to the dialog
that asks me if I want to "improve" the import. Apparently that's when
things get screwed up. So what I did was to substitute the VRD fix for
the old one and pretend that it was the same as far as MF4 is
concerned.

Now it works. Maybe I need to change my mind about VRD/MF4. But it
still seems to be a lot of fooling around just to fix something that
should not be screwed up.

BTW, the adjustment was 500 ms, or 1/2 second. That's 15 frames. I
wonder if that is significant.

Also the out of sync condition gets progressively worse each time the
scene changes from the singer to something else and back. So that 1/2
second was a compromise to get the overall clip as balanced as I
could.

I suppose I could split the clip into pieces and apply the right about
of sync shift to each segment. But then when I glue them back together
I might experience gaps in the audio which is far worse than lip sync
problems.

Thanks for the assistance. You were a lot more helpful than the babies
who whined about my criticism.





--

"The scientist is possessed by a rapturous amazement at the
harmony of natural law, which reveals an intelligence of such
superiority that, compared with it, all the systematic thinking
and acting of human beings is an utterly insignificant reflection.

"This feeling is the guiding principle of his life and work,
in so far as he succeeds in keeping himself from the shackles
of selfish desire. It is beyond question closely akin to that
which has possessed the religious geniuses of all ages."

--Albert Einstein

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