Posted by Alan Moorman on 12/06/06 01:48

On 5 Dec 2006 06:34:00 -0800, "blackburst@aol.com"
<blackburst@aol.com> wrote:

>
>Scott Dorsey wrote:
>> This is the normal state of affairs in the 21st century. The usual thing
>> people say is that "nobody else ever complained."
>>
>> Soon everyone will be watching 1:1.33 images stretched out to fit their
>> widescreen TV, with synch drifting four or five frames off in either
>> direction. Welcome to hell.
>> --scott
>
>Video/Audio synch has long been a problem. In the beginning, analog
>"live shots" were sent back to the studio via microwave, where the
>video and audio then took different "paths". The video went through a
>frame synchronizer: Early units imparted 2-4 frames of delay, but that
>was eventually reduced to under a frame. Then came satellite for ENG,
>and again, there was an even larger delay problem (10+ frames),
>although it affected the audio to the same degree as the video.
>
>Along came digital, and now we had the problem of too-slow A-D and D-A
>converters: The audio units were fast and transparent in the time
>domain, but the video conversion was "much" slower. Now we have HD
>(hi-def), which currently has MUCH more information to convert, so V/A
>delay is again a big issue. Faster processors will help, but the
>separate paths for audio and video will continue to cause problems.
>
>I am working with a manufacturer on a solution: A time reference signal
>encoded into both the video and audio at the source, and a
>reader/resolver at a certain point in the receiving end. But it only
>works in the digital domain. And we have another company who just
>introduced a competing design. Yes, it's hell, but we're trying to make
>it freeze over!
Hope that works for all of us!

I'm a fan of "Jeopardy" and my local station has a problem when they
come back from the first break in the show -- the audio is about a
second out of sync, and whoever has to patch something to get it back
in sync takes anywhere from :10 to a minute to get it done.

The other day, they came back from the break, and the sync was off,
and stayed that way for a minute, then the show suddenly jumped
forward in time by, oh, say a minute -- several questions and answers
went by in the flash of an edit -- and then after about :30, they put
it all back to the normal mode.

I wonder what the h__ is going on there. This only happens after
the first commercial break inside the show. . . .

Alan

....who is enjoying being retired....

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