Hi Lukas, > the uvc driver works great from the scratch for my logitech quickcam 5000 > pro. Gratulations on this nice job done !
Thanks :-) > There are some issues while capturing (using opencv) like: > Corrupt JPEG data: premature end of data segment > Corrupt JPEG data: 403 extraneous bytes before marker 0xd9 > . > which actually mess up the image, but don't occur too often so the > stream is nearly ok. I'm sure you're already aware of that. This occurs when some USB data packets are lost. Most webcams use isochronous transfers, which don't provide any delivery guarantee, so this can happen from times to times depending on USB bandwidth usage. Unfortunately, data packets don't include a position indication, so there's no way to find out that a packet was missing to recover gracefully (by padding the image with blank space for instances). > I have one question regarding the driver: > > is it possible to set some capture properties with modprobe while > loading the driver ? Capture image size and framerate would be > interesting for webcams. (quickcam pro 5k is able to capture at about > 1200x900 which is not allways desired, especially in the field of real time > object recognition) The capturing takes about 41% of cpu power on an athlon > 64 bit 3700+ processor which is quite a bit. This is not currently supported. However, you can easily set the image size and frame rate from user space applications using the VIDIOC_S_FMT and VIDIOC_S_PARM ioctls. > regarding to the old pwcx phillips driver the quickcam 4000 takes about > 15%-25% of CPU power for 640x480 pix. the capture image size can be set by > a parameter like 'modprobe pwcx size=sif fps=15' which is very convenient. Are you aware of any application that doesn't set the size before streaming ? Cheers, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
