Hi Brian, On Friday 25 January 2008 02:13, Brian Pin wrote: > I ported linux-uvc driver on our simple os system, which is quite the same > as linux, since I ported the all the usb (hcd and hub, message..) from > Linux.
Nice. Just out of curiosity, what kind of OS is this ? And what kind of platform does it run on ? I'm always interested in hearing about real-life projects using the Linux UVC driver. > The question is our verification system runs at a FPGA platform and I can > successfully connected to a Microsoft camera, get its descriptors and all > probing and initialization procedures is done. > > When I started streaming, the frame rate is nearly 1~2 FPS, that is so > confusing to me. I have tried settings from 800x600(30FPS), to > 160x120(30FPS) none of them achieve higher than 2 FPS. > > My question is, although our FPGA runs at 40MHz, memory speed is 60~75MHz, > is this possible to achieve 30FPS? We have an USB analyzer which captures > lots of "IN" tokens from my host to the cam(one IN per microFrame), and the > cam just responds with zero bytes data. When I test the device on PC , it > works fine to 30FPS. Do you use the same userspace software on your FPGA and on the PC ? > So I am wondering if there is any cause that makes the device dynamically > changing to slow framerate? Lightning conditions might play a role but should not lower the frame rate that much. Does your system have an EHCI (USB 2.0) controller ? USB 1.1 is obviously slower, and if the camera doesn't support MJPEG compression frame rates on USB 1.1 will be quite low. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
