Bug 359647 – media-plugins/gst-plugins-v4l fails with linux-headers-2.6.38+

• Status: RESOLVED WONTFIX
• Product: Gentoo Linux

[Description Christoph Brill (egore) (RESIGNED) 2011-03-20 19:01:27 UTC]

gst-plugins-v4l2 cannot be built against linux-headers-2.6.38 because of missing videodev.h. Symlinking videodev2.h to videodev.h works (compile tested, not yet runtime tested)

Reproducible: Always

[Comment 1 Christoph Brill (egore) (RESIGNED) 2011-03-20 19:01:51 UTC]

Add blocker

[Comment 2 Rafał Mużyło 2011-03-20 20:31:06 UTC]

Actually the real fix is to remove that header - that's how it got fixed in gst-plugins-good 0.10.28.

But perhaps this is a good point to consider switching to libv4l - like i.e. vlc.

configure option: '--with-libv4l2'

[Comment 3 Nirbheek Chauhan (RETIRED) 2011-03-20 20:55:18 UTC]

Since the fix is in 0.10.28, what's the problem?

[Comment 4 Mart Raudsepp 2011-03-21 02:32:15 UTC]

I guess unsynced tree, as the version where this is fixed was committed to tree 8.5 hours before this report?
Though I wonder if gst-plugins-v4l (note the lack of 2 in the end of that package name) compiles and works anymore.

[Comment 5 Mart Raudsepp 2011-03-21 02:33:09 UTC]

Oh, and libv4l2 is discussed in bug 250079

[Comment 6 Rafał Mużyło 2011-03-21 03:02:45 UTC]

compiles: definitely not - sys/v4l/gstv4lelement.h includes linux/videodev.h

works: haven't checked, but chances are neither - as I said elsewhere: header was removed, cause it's removed in kernel

I'd say best part of the mentioned bug is final Samuli's comment.

But if a solution is already present in that bug, why wasn't it implemented ?

[Comment 7 Arun Raghavan (RETIRED) 2011-03-21 11:55:39 UTC]

The problem you've reported is in gst-plugins-v4l not gst-plugins-v4l2

[Comment 8 Kobboi 2011-03-29 12:36:34 UTC]

Same problem with libv4l-0.8.1:

log.c:22:28: fatal error: linux/videodev.h: No such file or directory
compilation terminated.

[Comment 9 Mike Thompson 2011-03-29 15:21:38 UTC]

I've just hit the very problem with libv4l-0.8.1 this morning.  I did not find a bug for it--do I need to file a fresh bug report for libv4l?

[Comment 10 Olivier Crete (RETIRED) 2011-03-29 17:15:56 UTC]

Actually, this is a non-bug.. 
With 2.6.38, v4l1 has been removed from 2.6.38 and all drivers have been ported to v4ol2, so you should just use gst-plugins-v4l2

When 2.6.38 goes stable, we'll just p.mask gst-plugins-v4l

[Comment 11 Mike Thompson 2011-03-30 14:32:25 UTC]

But wait--there's still a problem.  There may be an upgrade path for gst-plugins, but there doesn't seem to be one for what I was talking about:  libv4l.  This library, which supports both V4L and V4L2, is a dependency for xine-libs, kopete, and vlc, plus ten other packages.  (I have the first three installed.)

If linux 2.6.38 breaks libv4l, there will be problems.  In the meantime, while 2.6.36-r8 is the latest stable version (and V4L is still in the kernel), I might just try the trick that someone suggested in the forums:
  ln -s videodev2.h videodev.h

So, am I back to needing to file a separate bug?

[Comment 12 Arun Raghavan (RETIRED) 2011-03-31 09:06:51 UTC]

(In reply to comment #11)
> But wait--there's still a problem.  There may be an upgrade path for
> gst-plugins, but there doesn't seem to be one for what I was talking about: 
> libv4l.  This library, which supports both V4L and V4L2, is a dependency for
> xine-libs, kopete, and vlc, plus ten other packages.  (I have the first three
> installed.)

Do these apps actually use actually require V4L (and not V4L2) APIs? I suspect not in most cases.

> If linux 2.6.38 breaks libv4l, there will be problems.  In the meantime, while
> 2.6.36-r8 is the latest stable version (and V4L is still in the kernel), I
> might just try the trick that someone suggested in the forums:
>   ln -s videodev2.h videodev.h

That's not a very good idea. libv4l ships a copy of the deleted videodev.h, so you need to patch apps if they're actually using videodev.h to use this replacement header (but really, they should just be ported to v4l2 - the v4l interface will go away completely in a while).

[Comment 13 Mike Thompson 2011-04-01 01:00:08 UTC]

I don't know for sure what will happen with libv4l.  This is clearly an issue for the respective upstream providers to resolve--they have to be aware that 2.6.38 is putting the hammer down on V4L.

libv4l comes from the main upstream of all the video-driver magic, linuxtv.org.  Surely they know what is going on with the kernel!  The question lies with the packagers who depend on libv4l.  If they're using the library to get at V4L2, they're probably OK, but if they're working with the old API, they're the ones that will have to adjust.

And by the way, that symlink trick with the header files didn't work for me.  I think it was supposed to work with gst-plugins, but the emerge for libv4l failed when I tried it there.  I downgraded linux-headers to 2.6.36.1 and got things to compile.

So I have my answer:  this is an upstream problem, and not the subject for a Gentoo bug.

[Comment 14 Samuli Suominen (RETIRED) 2011-04-28 16:06:37 UTC]

Removed from tree.    Use gst-plugins-v4l2.