[FreeBSD 8/9] USB webcamd and video4bsd: Call for testing

Henry Hu henry.hu.sh at gmail.com
Tue Jan 19 17:33:16 UTC 2010


On Sun, Jan 10, 2010 at 9:37 PM, Hans Petter Selasky <hselasky at c2i.net> wrote:
> Hi,
> During the last couple of days I've spent some time to finish my webcam
> daemon. My webcam daemon is basically an application which consists of
> userspace Video4Linux USB webcam drivers and some uLinux glue code which links
> with libc, pthreads and libusb. The webcamd talks to /dev/video_daemonX which
> is provided by the video4bsd kernel module. There is full support for
> mmap/read/write/open/close. poll is not supported.

I've tested on my webcam and it works here.
I have an USB Video Class webcam:

ugen2.2: <Vega USB 2.0 Camera. Vimicro Corp.> at usbus2, cfg=0 md=HOST
spd=HIGH (480Mbps) pwr=ON

This is the first time it works in FreeBSD! Thanks a lot!
Currently, it works with -s vga and -s cif. There are many other modes
supported by the webcam, but pwcview just does not support them. This
webcam supports at most 1280x1024, and the quality is clearly better
than 640x480.

There are some problems, however. First, when I start pwcview with an
unsupported mode, the content of the window is green, and I cannot
kill the process. Only after terminating webcamd can I terminate the
Second, I cannot restart pwcview without restarting webcamd. At the
second time I start pwcview with -s vga, the window is green, and I
cannot kill it. The situation is similar to unsupported size.

I've also tried applications such as pidgin, skype and mplayer.
However no one successfully played from the webcam. I doubt it needs
some extra work.

I've changed pwcview a bit to keep the settings in internal variables
instead of fetching them every time. Else I cannot change most
parameters.  Maybe the webcam only supports a certain set of setting
values, and use the nearest value after setting them.

Thanks again for the great work! It never caused any kernel panic, and
the programs are fairly stable.

> Basic operation and idea:
> /dev/video_daemonX is the interface for the webcamd. /dev/videoX is the
> interface for the V4L application. The video4bsd transports all data between
> these two devices. In the case the V4L application is using mmap, no data is
> copied due to shared kernel memory buffer!
> Licensing issues:
> Effectivly the webcamd userland program becomes GPL'ed due to the V4L USB
> drivers which are GPL licensed. Some files inside the webcamd remains BSD
> licensed which allows for building similar BSD licensed daemons.
> The rest of the code is BSD licensed.
> Source code:
> 1) FreeBSD 8-stable
> 2) Apply the patch below and re-install libusb in /usr/src/lib/libusb:
> http://p4web.freebsd.org/chv.cgi?CH=172876
> http://perforce.freebsd.org/chv.cgi?CH=172876
> 3) Compile ulinux (webcamd + libv4l + pwcview) and video4bsd (must be checked
> out in the same folder due to dependencies)
> svn --username anonsvn --password anonsvn \
>      checkout svn://svn.turbocat.net/i4b/trunk/usbcam/video4bsd
> make all install
> kldload video4bsd
> svn --username anonsvn --password anonsvn \
>      checkout svn://svn.turbocat.net/i4b/trunk/usbcam/ulinux
> make fetch
> make patch
> make all
> make install
> # this will attach to the first detected webcam:
> ./webcamd
> # this will try to attach to the given USB unit, interface and V4B unit.
> ./webcamd -d ugen4.1 -i 0 -v 0
> # this will display webcam contents from /dev/video0 by default.
> ./pwcview/pwcview
> Feedback and bug reports are welcome.
> Yes, I am working on getting this into ports!
> Known issues:
> 1) If you detach the USB webcam you need to manually restart the webcamd.
> --HPS
> Support: I will be available at #bsdusb on efnet during the day.
> _______________________________________________
> freebsd-multimedia at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-multimedia
> To unsubscribe, send any mail to "freebsd-multimedia-unsubscribe at freebsd.org"


More information about the freebsd-multimedia mailing list