[mythtv-users] hardware questions for HD to SD playback

Johnny jarpublic at gmail.com
Tue Sep 1 07:47:33 UTC 2009


> Johnny / anyone: What if the input video is 720p (or xp)

I assume you are asking what happens when you play a progressive video
on an interlaced screen? If so then I believe it is quite simple. The
video card just splits the progressive frame into two fields and sends
them one after the other. Although others that are more knowledgeable
than I can correct me if I am wrong. The reason that deinterlacing is
complicated is when stuff is filmed with an interlaced camera or
because of the telecine process of converting film 24p film to NTSC,
so that you are end up with 60 interlaced fields a second arranged in
30 frames. In this case it isn't simple because stuff can change or
move between the two fields. So just sticking them together in a
single frame will result in the standard "jaggies".

>
> Jamie: also be aware there is likely to be an overscan issue.

True, the overscan is annoying to me but not too bad of a problem.


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