On Mon, 1 Jun 2009, Stefan Kost wrote: > I have implemented support for V4L2_MEMORY_USERPTR buffers in gstreamers > v4l2src [1]. This allows to request shared memory buffers from xvideo, > capture into those and therefore save a memcpy. This works great with > the v4l2 driver on our embedded device. > > When I was testing this on my desktop, I noticed that almost no driver > seems to support it. > I tested zc0301 and uvcvideo, but also grepped the kernel driver > sources. It seems that gspca might support it, but I ave not confirmed > it. Is there a technical reason for it, or is it simply not implemented? userptr support is relatively new and so it has less support, especially with driver that pre-date it. Maybe USB cams use a compressed format and so userptr with xvideo would not work anyway since xv won't support the camera's native format. It certainly could be done for bt8xx, cx88, saa7134, etc. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
