Posted by Rick Merrill on 12/01/06 22:51

Roy W. Rising wrote:
> "Brian" <brian.english@sas.com> wrote:
>
>
>>I think it's impossible to tell looking at a TV broadcast anyway. Half
>>the time the audio and video aren't synched up right in the broadcast to
>>begin with. I was watching a football game the other day and the
>>announcer's mouth moved a good 3 tenths of a second before the sound came
>>out of the TV, and he wasn't lip-synching :)
>
>
> It was far from "impossible to tell looking at a TV broadcast". I found it
> quite easy. Further, sometimes she was in sync, so it could not have been
> the kind of transmission problem that sometimes causes what was seen on the
> football game. More often in that case, there is a video effects device
> that slows the picture by a frame or more. The rule for sync perception is
> "plus or minus one frame" is OK. More than that, it's noticeable.
>

Isn't it likely that those transitory sync problems are due to MPEG
transmission compression?

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