[mythtv] codec that deals best with badly synced video

Jeremy Oddo mythtv-dev@snowman.net
Thu, 7 Nov 2002 23:05:07 -0800 (PST)


> From a discussion on the mjpeg list it was mentioned that vcr's
> typically  have horrible video sync which will usually give encoders a
> fit, resulting in  high cpu usage and/or a/v sync problems or dropouts.
>
>
[SNIP...]
>
> The problem I experience is that every 20-30 seconds or so I get an
> audio  dropout and a video hiccup and then a second or two later the 2
> get in sync  again.
>
I know this may be out in left field, but this wouldn't have anything to
do with DF vs. NDF or a timecode issue would it?  It's my understanding
that VHS doesn't really lay down timecode.  I forget the formula, but I
think that with DF you would drop 18 frames over the first 9 minutes, do
nothing on the tenth minute, then continue.  So, after 20 minutes you
would need to have dropped 36 frames (or 1 second +06) and after 30
minutes you'd need to drop 1 second +24 (or almost 2 seconds).  Don't know
if this even factors into the whole mix or not.

Anyone know how standard broadcast, digital broadcast, and PVRs record? 
DF or NDF?


Jeremy