Hello, 1) I will try this WE on a different computer which has USB 2.0 port directly on motherboard and keep you update 2) I've included all trace here : http://forums.quickcamteam.net/showthread.php?tid=860 3) I have the problem with guvcview, luvcview, mplayer, kopete, skype... So I don't think that is an application issue
Thank you for your help ! 2009/6/25 Brian Pin <[email protected]>: > Hi > Maybe there are some possible reasons.. > 1) dropping by the device because the host is too slow to drain the data, -> > use a different host to test > 2) dropping by the host uvc driver, -> turn on the trace to maximum to check > if there is a drop > 3) dropping by the application above uvc driver, -> probably be some timing > issues or synchronization issues..don't know how to test, maybe a different > application would tell the difference? > > Good luck > > > On Wed, Jun 24, 2009 at 5:29 PM, Saint Germain <[email protected]> wrote: >> >> I've tried disconnecting all PCI cards except the USB controler and >> using it in different slot, but same results. >> I also tried booting with acpi=off but no such luck. >> >> I will try on another computer this week end. Really strange... I never >> had any problem with this USB controler. >> >> I also have a Philips Toucam Pro (need pwc driver) which if connected >> on the same port works correctly without a single dropped frame (but >> with a poor definition, something about the previous pwcx module being >> reimplemented). >> >> Maybe some freak combination of motherboard + USB controler + UVC >> module ? >> >> I'll keep you updated this WE. >> >> Thanks for your help ! >> >> On Wed, 24 Jun 2009 23:46:11 +0100, Paulo Assis <[email protected]> >> wrote : >> >> > The YUYV fps difference to MJPG, IMHO, can only be caused by the >> > frame size. MJPG is compressed so it can be some 10 times smaller >> > compared to YUYV. This also indicates that CPU is not a problem since >> > MJPG requires a lot more CPU (needs decompressing) >> > So if memory is also not a problem, the only thing left is the USB >> > connection. >> > >> > I'm just intrigued by the flickering, even at 20 fps video should be >> > acceptable, I'm guessing the driver is dropping some data, in yuv >> > case the entire frame as incomplete frames are droped by default, in >> > the case of MJPG since there is no way of knowing the complete frame >> > size (it varies due to the compression process), you just get part of >> > the frame and that causes the ficker. >> > >> > In any case all seems to point to the usb connection, so I would run >> > some tests on that. >> > >> > Best regards, >> > Paulo >> _______________________________________________ >> Linux-uvc-devel mailing list >> [email protected] >> https://lists.berlios.de/mailman/listinfo/linux-uvc-devel > > > > -- > Best Regards > Brian > _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
