Hi, I've just got a Logitech QuickCam E 3500 Plus (046d:09a4) that is an UVC device and is supported by the UVC kernel module. I'm under Kubuntu 8.10, kernel 2.6.27-8-generic #1 SMP.
The problem is about the framerate, and specifically with the auto exposure feature of the camera. Basically when there's not enough light the camera is compensating (very well actually) and the framerate drops to 3fps, when there's daylight it still compensate and the framerate is about 15/20fps (@640x480). The odd thing is that sometimes (but I haven't been able to reproduce it) the camera just doesn't use the auto exposure feature when I plug it in and, even if the image is darker, I get constant 30fps. Now I would really like to know how to turn off and on the auto exposure and white balance feature of the camera from the driver. If I try to turn off the auto exposure from the luvcview interface, I get "Set Auto Exposure off error" in the standard error. For the record, when I plug the camera, syslog says: Nov 15 14:28:27 greywolf kernel: [11314.937051] usb 1-2: new high speed USB device using ehci_hcd and address 7 Nov 15 14:28:28 greywolf kernel: [11315.178592] usb 1-2: configuration #1 chosen from 1 choice Nov 15 14:28:28 greywolf kernel: [11315.178862] uvcvideo: Found UVC 1.00 device <unnamed> (046d:09a4) Nov 15 14:28:28 greywolf kernel: [11315.209087] input: UVC Camera (046d:09a4) as /devices/pci0000:00/0000:00:02.1/usb1/1-2/1-2:1.0/input/input9 Nov 15 14:28:29 greywolf kernel: [11316.213276] 7:3:1: cannot get freq at ep 0x86 Notice the last line! Sometimes the last line is slightly different, as follows: Nov 15 14:39:34 greywolf kernel: [11981.793172] 9:3:1: cannot set freq 16000 to ep 0x86 And sometimes (often, but not always!) I also get the following in syslog when I plug the cam, but the error doesn't stop the cam from working: Nov 15 14:39:34 greywolf kernel: [11981.960176] uvcvideo: Failed to query (1) UVC control 1 (unit 0) : -110 (exp. 26). Maybe the last line is about the snapshot button that is on the camera? Anyways the camera works even if I get these "soft" errors in syslog. Help would be really appreciated. Thanks a lot to everybody. Mauro _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
