#VTR Skipping Frames
30-Aug-93 11:45:12
Sb: #55406-#VTR Skipping Frames
Fm: MARTIN G FOSTER 70303,456
To: Michele Bousquet 100237,162
Michele,
>>1. A Jpeg card would ordinarily come with its own software to compress >>a
list of TGAs to an animation file;
Yes, this seemed to be the case for the ones I saw at Siggraph.
>>2. When you want to view the 24-bit animation you must put it out to >>video,
you can't view it onscreen, say on a Targa+ (until further >>technology
permits) so a home VCR is ideal for inexpensive previewing;
Not exactly, you can view the animation by playing it in real-time out to a
monitor from the JPEG card. Similar to how you view a flic, except much higher
quality and it is recordable, if you wish.
>>is the compressed file file bigger, smaller or similar to the original
>>space taken up by the Targa files?
considerably smaller. Say from 10 to 30 times smaller.
>>2. Would the realtime output to BetaSP sometimes not be as good as
>>frame-by-frame because of quality loss from compression? Or could you >>just
use a low compression ratio and save the quality? Or if the >>compression ratio
is low the Jpeg card cannot keep up with 30fps?
The quality will not be as good as BetaSP, although they often call it
near-betaSP quality at the highest quality setting. They may be a situation
where there is so much moving on the screen that you need to lower the quality
to maintain a fixed 30 fps.
>>A note: I am in PAL-land so 25fps is the concern, not 30, if this >>makes a
difference.
The manufacturer would probably have to make a PAL specific card, or one the
does both PAL/NTSC.
Hope that helps.