gem_video

umläute zmoelnig at iem.mhsg.ac.at
Wed Feb 16 14:38:32 CET 2000


Hi !

Actually, i'm experimentig a little bit with gem + video;

hw-specs:
PII - 350MHz
guillemot 3d prophet geForce256 DDR-DVI (should be fast enough)
hauppauge WinTV primio (the cheapest one i could get with TV-IN)
WinNT

Trying pix_video i have a few problems concerning speed;
the very maximum i could do is 320 * 240 pixes (but this might be
because of the poor TV-card or because i haven't found the correct
software to change this)....should it be possible to change the dimen of
the captured video from within gem ?
when loading the patch i get a "connected to video at 320 240" or
something very similar; when i try to change the dimen and start
rendering, i will get the permanent error "pix_video:: couldn't capture
enough pixels" (or simile)

the frame-rate is something very weird, i already did 20-25 frames,and
it only used 80-83% of my cpu; but it wasn't really smooth, and
smoothiness did NOT CHANGE by doing a frame-rate of only 15. Neither
changed the cpu-load (witch was very ok, for everything reacted quite
fast)

then SUDDENLY, the video came in *quite* smooth, and the cpu-load
exploded to 100%; again now real changes for various frame-sizes
(except, of course, that at 15frm/sec it wasn't smooth any longer, but
load stayed at 100% !).
I don't have any idea, why the behaviour changed; (by the way,
*yesterday* i had a constant cpu-load of 100%)

since i only will pass through the video-signal (and do nothing with it,
just adding one or two gem-objects) i would highly appreciate any
solution that will cost nothing (you know, watching TV on the pc isn't
very hard work for the cpu too), so is there any possibility to do a
very simple pass-through, or where can I save calculations (p.e. do we
really have to copy the captured frame into an internal rgbA-buffer; or
is this less important ?)

when i now try the whole patch (that is:: pass through the video signal;
render a simple model; do very few calcs on audio), the video will
freeze after some (or one (?)) frame.s, the rest will be VERY slow;

mfg
hannes

of course i have removed all the float-guis



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