If should get at least 27, 28 fps with this card. The read syscall can be slower than a memcpy from a mmap'ed device. Something must be wrong with your code, check out if you are using double buffering properly. Best regards -- Gleicon S. Moraes gleicon@xxxxxxxxxxxx gleicon@xxxxxxxxxx http://planeta.terra.com.br/informatica/gleicon ----- Original Message ----- From: "André Luiz Ribeiro Moutinho" <andre.moutinho@xxxxxxxxxxxxxxxxx> To: <video4linux-list@xxxxxxxxxx> Cc: "Mauricio Micoski" <mauricio.micoski@xxxxxxxxxxxxxxxxx>; "Marcelo Ferreira Vinhas" <marcelo.vinhas@xxxxxxxxxxxxxxxxx> Sent: Tuesday, January 29, 2002 6:17 PM Subject: capture speed improvement > Hi > > I am developing a capture and video multicast. I have > used the VIDIOCMCAPTURE and VIDIOCSYNC ioctls to read > 1 frame from the grabber (struct video_mmap.frame = 0) > > I could accomplish this but the maximum frame rate is 15. > I would like to know how I can improve the video frame rate. > I need a higher frame rate and the CPU usage is very low. > > What about using the read syscall ? Is it faster than mmap > method ? Is threre a faster method ? Do I have a DMA access > time limit ? > > I am using the PixelView Play TV Pro and running under > a Pentium 300Mhz equivalent machine and linux RH7.1 > kernel 2.4.7. > > Thanks a lot, > > André Luiz R. Moutinho > Computer Engineer, COMPSIS - Computadores e Sistemas Ind. e Com. Ltda > moutinho@xxxxxxxxxxxxxxxxx, moutinho@xxxxxxxxxx > Voice: +55 12 394-13966 Fax: +55 12 322-0888 > > > > > > > > _______________________________________________ > Video4linux-list mailing list > Video4linux-list@xxxxxxxxxx > https://listman.redhat.com/mailman/listinfo/video4linux-list >
