Sorry for the late reply. Meanwhile, kernel was upgraded to 2.6.20.6. Selon Laurent Pinchart <[EMAIL PROTECTED]>: > > uvcvideo: Failed to submit isoc URB 0 (-28). > > -28 is -ENOSPC, which means the driver can't allocate USB bandwidth.
This is stunningly right. Even with the protocol overhead, the exact port and webcam specifications, I wouldn't have thought that 2 streams each of around 14.7MB/s could saturate it. > There's not much I can do here. Two webcams at high resolutions in > uncompressed mode exceed the USB bandwidth. Could you try using the MJPEG > format ? I've rather tested by reducing the framerate of any of those from 25 to 15 fps, and the 2 webcams were able to stream. So indeed, you were right in that USB2.0 bandwidth is the limiting factor here. During that test (640x480, YUY2), reducing the framerate of a Logitech Pro 5000 to 15 fps yielded packet drops (due to error bit being set). Is this a bug, or such phenomenon is obvious? I'm not very confident on what is reported by the driver/webcam, because: 1) For Logitech QC Pro for Notebooks, reports uncompressed [EMAIL PROTECTED] while happily capturing at 30fps 2) For QC Pro 5000, reports and manages uncompressed 640x480 at 30fps Thanks and best regards, Christophe GISQUET _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
