Re: [Qemu-devel] [PATCH] USB Webcam Redirection

["andrzej zaborowski" <balrogg@gmail.com>]

Hi,

On 24/09/2007, Arnon Gilboa <arnon.gilboa@qumranet.com> wrote:
> Attached is an updated patch for supporting isochronous transfers in
> redirected host USB devices. The initial goal was supporting USB 1.1 Webcam.
> Tested on WinXP guest with several Webcams. Works on USB 1.1 Webcams, as
> well as most USB 2.0 Webcams (backward compatibility) on low resolutions.
> Some jitter is visible in the video stream, and it will be fixed.
>
> Notice USE_ASYNCIO, which defines whether to use signal based async io or
> polling for receiving urbs. Currently it is disabled, so polling is used,
> but it does not seem to affect the performance because it uses the
> non-blocking USBDEVFS_REAPURBNDELAY ioctl. In order to use the signal based
> async io, the patch to usb-uhci.c should be applied.
>
> The patch includes parts of previous patches posted in Qemu-devel:
> usb_host_update_interfaces (from
> qemu-0.9.0-usb-multi-configs.patch),
> usb_linux_update_endp_table (qemu-usb-host-async.patch) as well as some
> other lines of code.
>
> I am currently working on the ehci emulation for fully supporting USB 2.0
> isochronous devices.
>
> Waiting for your comments,

I pushed both patches into CVS, but I haven't tested it with any
devices with ISO endpoints yet, so please do. I made some identifiers
static and also removed the first qemu_free to avoid double freeing
in:

    ret = usb_linux_update_endp_table(dev);
    if (ret) {
        qemu_free(dev);
        goto fail;
    }
...
fail:
    if (dev)
        qemu_free(dev);

Regards