Date: Sat, 12 Sep 1998 12:30:01 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: nate@mt.sri.com (Nate Williams) Cc: pusateri@juniper.net, freebsd-multimedia@FreeBSD.ORG Subject: Re: NogaTech PCMCIA video cards Message-ID: <199809121030.MAA20689@labinfo.iet.unipi.it> In-Reply-To: <199809112200.QAA14278@mt.sri.com> from "Nate Williams" at Sep 11, 98 04:00:07 pm
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> FWIW, a PCMCIA camera has *TONS* more bandwidth and *TONS* less good to hear that. but just for curiosity, how much more bw ? I guess the ISA bus tops at some 4Mbyte/s, a 33 MHz, 32-bit PCI bus can do 133 Mbytes/s during burst transfers, and 320x240x30fps YUV16 video should be around 5MB/s. > We used a parallel port camera for awhile, but the performance and load > on the system became so bad that we were forced to switch to a PCMCIA > camera, which works much nicer. (Note, this is under Win95, but the > hardware issues are the same as in FreeBSD.) well for the paraller port thing, a poor driver can make a lot of difference. I rememver using a quickcam with vic under FreeBSD, and the system was still usable on a 486/66 with the user space driver whereas a P5-133 was doing terribly using a kernel space driver (essentially the reason was, the kernel driver was/is not preemptable, so even mouse/keyboard interrupts had to wait!) cheers luigi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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