[libdc1394-devel] Re: Re: Newbie question about transfer rates
Capture and control API for IIDC compliant cameras
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From: Korkut G. <kor...@gm...> - 2005-03-07 04:46:22
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Linux box that I am using is a p3-800 with 512 RAM. Nearly all services are disabled (eventually i am planning to use libdc together with DirectFB for display.) I suppose my case is quite isolated and i guess it has something to do with video1394 driver. I dont have .conf file with me but I am using default A602f.conf file pointing to video1394 device at "/dev/video1394" (which i created by mknod because when i modprobe video driver it doesnt create devfs nodes). Funny that i am able to reproduce same behaviour with Coriander as well (newest from CVS). On Coriander even increasing buffer size to 200! didnt solved the problem. It doesnt corrected when I reduce shutter speed to minimum too. I was experimenting with cammonitor, and i tried to reduce the frame size to 640*480. It looked like it solved the problem but tataaa: this time images are represented with 1 sec ~ delay ! Since nobody is facing same problems, bug should be me ! I think it has a deeper reason like you've stated. I'll try to update my drivers to latest versions and see how. This annoys me because on same hardware, WinXP driver and original software runs without any problem (max framerate and and max fps). Of course this is not a real comparison but XP drivers are *not really* superior to Linux drivers :) > Hmmm... I can't reproduce your problems on a first try. My tests run > without trouble using identical settings to yours. I have an old > Basler A602f and I'm using Fedora Core 2 (with a slightly tweaked > kernel 2.6.5) with libdc1394 1.0 and raw1394 0.10.1. > > I think you are right about it being a DMA transfer or timing problem. > Getting only half the frame rate suggests that you are only > receiving every second frame correctly. > > From past experience, I would suggest that you are pushing the limits > when you demand maximum frame size with maximum frame rate and maximum > integration time. I know that it should work in theory (and it does > work with my set-up here) but I suspect that some part of the Linux > IEEE 1394 system is just a bit flaky when try to run too fast. It > might even depend on what else is running on your system. When we > have serious work to to we tend to back off a bit and leave a guard > band in terms of bandwidth and shutter timing. > > What is in your .conf file? > > Johann > > -- > Johann Schoonees Research engineer > Industrial Research Limited, PO Box 2225, Auckland, New Zealand > Phone +64 9 9203679 Fax +64 9 3028106 http://www.is.irl.cri.nz/ > Camwire's home: http://kauri.auck.irl.cri.nz/~johanns/camwire/ > > --__--__-- > > _______________________________________________ > Mailing list for libdc1394-devel > lib...@li... > https://lists.sourceforge.net/lists/listinfo/libdc1394-devel > > End of libdc1394-devel Digest > |