Re: droping frames

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Dennis Pierce (dpierce++at++dolphin.digital.net)
Tue, 29 Oct 1996 07:42:09 -0500


RE: the phase-locked loop issue...

Are you trying to save "real-time" 15 fps to disk? That clocks
at about 15 MB/s which is a bit steep unless you have two or
three striped drives. At least that's the output rate if you're
using 640x480x3. PAL will differ but the bandwidth issue will
still remain.

So, why not just run your app non-real-time and snap images whenever
you have a new frame ready?

Another issue that you may or may not be seeing is that of
interlaced vs non-interlaced images. For TV, the images are
sent at 60 fields/s with each field being either the even
scan lines or odd scan lines. The "trick" to make good video
one frame at a time is to generate 60 fields/s (sorry, too much
NTSC influence) - in your case, 50 fields/s, then break each
field into an even set of lines and an odd set of lines, then
ship these interlaced fields to the video maker of your choice.
This will help with temporal aliasing that looks absolutely
horrible and may be the source of what you are calling "bumps".

Hope this helps and good luck!

bye.

-- 
--
Dennis Pierce				dpierce++at++digital.net
POB 321206 CCB FL 32932			http://ddi.digital.net/~dpierce
011.407.784.8371
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