🚀 go-pugleaf

In article <1992Aug14.103330.1@research.ptt.nl>,  I wrote:
> 
> We recently performed an informal test to see if people were
> able to correctly align audio and video. The tested started with audio
> 500 msecs ahead of video, or 500 msecs behind. The sequence
> contained only a (continuously) talking head. The audio delay
> could be changed to get the sound synchronous. Hardly anyone
> was able to get it correct within 100 msec, and most scored
> between 100 and 200 msec, in either direction.

I'm afraid there's something important I forgot to tell about this...

I thought we did the test with original PAL-tapes,
but I now found out that they were coded according
to the CCITT rec. H.261-standard. This is a videophone
standard for coding pictures at around 64 Kbit/sec.
I f you are not familiar with this: it means a lot of
data-reduction. The result is that the frame rate was
around 10 Hz, and the pictures are of less quality than 
PAL. 

I will receive more accurate details in a few days,
but the average error was over 150 msec, in either
direction.
 
I intend to do the tests again with non-coded material as
soon as I have the equipment back, but this can take a while,
as it's now being used outside of our lab.
I wonder how well people will perform on the original tapes ...

I'm sorry for the inaccuracy in my orignal posting,  

Rob