Hello,
I've been playing around with Mc Clelland's
ov511-2.2.18-backport-1.33-1 driver and a usb Creative Webcam
III. I believe it takes too long to get one QCIF (176x144)
YUV420 frame (60 to 85 ms). I'm running 2.2.18 on a Pentium 3
550MHz PC.
I don't care loosing some frames, but definitely need
to capture each frame faster. This is the measured C source
code (using BetterC[1] library):
....
mmap.width = 176;
mmap.height = 144;
/* Chrono started here */
error = ioctl (vid, VIDIOCMCAPTURE, &mmap);
CHECK (NOT error AND mmap.width==176 AND mmap.height==144);
FROM
error = ioctl (vid, VIDIOCSYNC, &mmap.frame);
UNTIL error==0 LOOP
/* INVARIANT ( ) ;*/
printf ("VIDIOCSYNC ERROR:%d\n", errno);
error = ioctl (vid, VIDIOCSYNC, &mmap.frame);
END;
/* Chrono stopped here */
There're no "printf("VIDIOCSYNC ERROR:%d\n", errno)" on my
stdout, so there are no SYNC errors. Is there any way I could
speed this up? I need to get it done in about 30 to 40ms.
References:
[1] BetterC is a library that allows Eiffel-like exception
handling mechanisms with almost zero overhead during development
and zero overhead in production:
www-scf.usc.edu/~moissetd/betterc/ or search at freshmeat.
Thank you,
Matias.
--------------
Matias Freytes
Laboratorio de Comunicaciones Digitales
Universidad Nacional de Cordoba
Argentina
