Hi Les, On Tuesday 29 April 2008, Les Smithson wrote: > I'm trying to use motion > (http://www.lavrsen.dk/twiki/bin/view/Motion/WebHome) with a uvcvideo > driver on an Asus eeepc. The webcam is USB ID eb1a:2761 eMPIA Technology, > Inc. It mostly works, but every now and then motion captures a noise > frame. These look as though a green/yellow is missing, and have the > picture offset in both the X+Y positions. The problem is noticeably worse > under the strip lighting at work. I think the problem is also present on > uvcview as every now and then the picture flashes for no reason. > > I've tried with both the stock driver and the latest svn (r205) and it > behaves the same way. Is this a driver bug? Is there anything I can do to > try and debug it?
The artifact you noticed are due to a missing USB data packet. This can be caused by bus contention, bad cables, noisy electrical environment, ... The UVC protocol doesn't provide a way to detect missing data packets. When using video formats with a fixed number of bytes per frame the driver could drop incomplete frames, but this isn't possible when frames have a variable number of bytes (when using MJPEG compression for instance). I still have to implement that in the driver. I'll push the task up on my TODO list :-) Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
