Re: [Coriander-devel] v4l2loopback for coriander

[Stefan R. <st...@s5...>]

On May 29 Gordon Sinclair wrote:
> I have invested in a couple of very nice firewire cams which give me 30
> fps. I need to get them to work through coriander to my program using
> the v4l interface. That's when it all went wrong because the V4L1 API
> was removed in one of the Linux 2.6.38 pre-releases. The
> <linux/videodev.h> header doesn't exist any more and has been superseded
> by <linux/videodev2.h>. Thus I cannot build vloopback on my system with
> the kernel version 2.6.38-15-generic-pae
> 
> Is there a branch of coriander which does v4l2loopback?
> 
> I have taken a look at the code for vloopback but I don't understand it
> at all. The only other option is to roll back to a previous kernel.

Doing FireWire video capture via special low-level IEEE 1394 I/O kernel
interfaces instead of the V4L/ V4L2 interface has been, and still is, one
of the big mistakes of IEEE 1394 support on Linux.

The stop-gap solution for 1394 video via V4L, vloopback, was always
problematic by
  (a) being a project outside of the mainline kernel, thus risking
      breakage at any kernel update,
  (b) having to rely on a userspace process for DMA buffer queueing.
The very same problems apply to v4l2loopback of course.

To me, an IIDC to V4L2 kernel driver (as well as an IEC61883-2/-4 to V4L2
kernel driver) looks like a much more useful project.  Alas I have far to
little time for Linux projects myself for the time being to implement such
a driver.
-- 
Stefan Richter
-=====-===-- -==- ---==
http://arcgraph.de/sr/