interlaced video question for you XV experts

[Gene Heskett]

On Thursday 17 March 2005 23:26, Michel Dänzer wrote:
>On Thu, 2005-03-17 at 21:00 -0500, Jon Smirl wrote:
>> Is there really any point in making interlaced output like this
>> work?
>
>I think so, but we've already agreed that it's outside of the scope
> of basic mode setting...
>
>> Even a 200Mhz processor should be able to deinterlace on the fly.
>> All you do is copy the buffer to ever other line, that can't add
>> more than a few cycles.
>
>If it were that simple, people dealing with video would have wasted
> a lot of time. The fields aren't just two halves of a frame, they
> were all recorded at different times.

To put it a bit more precisely, at least in Never Twice Same Color 
(NTSC) field one is lines 1, 3, 5, 7 etc, then field 2 is lines 2, 4, 
6, 8 etc.  They are scanned in real time in that order in the camera 
also, so there is a very real possibility that there will be 
relatively large motion artifacts from one field to the next, so they 
must be reproduced on the screen in same order.  Combining them for a 
'progressive' display is going to be less than optimum.

I'm a broadcast engineer with 55 years experience in tv, or tv related 
fields.

-- 
Cheers, Gene
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