libv4l2 recent changes and future and v4l stream sharing

Scheduled: Friday, September 25, 2009 from 10:45 – 11:30am in Salon AB


Last years libv4l2 presentation ended with a slide future with
bullet points of features to be added, so where we stand today? And what will happen in the coming year?


Last years libv4l2 presentation ended with a slide future with
the following bullet points (abbreviated):

  • Add emulated controls
  • Better handle rotation
  • Software image quality enhancements:
    – White balance
    – Normalize
  • Emulated controls persistency

Actually quite a few of these have materialized in the recent
0.5.9x releases of libv4l. The talk will start with a short
talk on what has been implemented, and more importantly how
and the impact of this on existing applications and drivers.

Last year Brandon Philips gave a talk about sharing video devices between multiple applications using a userspace video server. This is the next frontier for v4l userspace, the second
part of this talk will describe several ideas how to handle
this and the advantages and disadvantages of each, after which
the intent is to further discuss this with the audience.


  • Hansdegoede

    Hans de Goede



    I’ve been a FOSS developer for 10+ years. I started writing
    kernel drivers when I got a motherboard with an unsupported
    hardware monititoring IC (The Abit ųGuru).

    End 2007 I wanted to do something for the greater good of Linux,
    I decided to start working on webcam compatibility as many webcams
    did have drivers floating around, but of mixed quality and most
    where outside the mainline tree because they did decompression
    of various cam specific format inside the kernel which was not
    acceptable in the mainline kernel.

    So I started working on getting drivers into the mainline kernel,
    for which I soon joined forces with Jean-Francois Moine, who was at that time porting the usb webcam driver framework gspca to v4l2
    and cleaning it up for the mainline kernel, and started rewriting existing drivers using that framework.

    I’m probably best known in v4l land for libv4l, the userspace library I wrote to more or less transparently handle the decompression of many proprietary webcam video formats in userspace, fixing the decompression part of the problem.

  • Me


    Brandon is a Kernel developer at Novell/SuSE Labs. He has presented at several technical conferences in the past including FreedomHEC Taipei, Linux Plumbers Conf and Ignite Portland 2 . In his spare time he tinkers with electronics and software, bikes, hikes and builds robots. For more information checkout his site.

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