gstreamer v4l2src fails with device=

[Shevek]

I have only one video device, it is /dev/video0.

This works:

$ gst-launch 'v4l2src ! xvimagesink'
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
(video plays)

This does not work:

$ gst-launch 'v4l2src device=/dev/video0 ! xvimagesink'
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data flow error.
Additional debug info:
gstbasesrc.c(2582): gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
streaming task paused, reason not-linked (-1)
Execution ended after 2532703705 ns.
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...

This means that I cannot read from video1, or use v4l2loopback or anything, since gstreamer apparently cannot deal with the device= setting.

For the record, here is part of gst-inspect v4l2src:

Element Properties:
  name : The name of the object
                        flags: readable, writable
                        String. Default: null Current: "v4l2src0"
  blocksize : Size in bytes to read per buffer (-1 = default)
                        flags: readable, writable
                        Unsigned Long. Range: 0 - 18446744073709551615 Default: 4096 Current: 4096
  num-buffers : Number of buffers to output before sending EOS (-1 = unlimited)
                        flags: readable, writable
                        Integer. Range: -1 - 2147483647 Default: -1 Current: -1
  typefind : Run typefind before negotiating
                        flags: readable, writable
                        Boolean. Default: false Current: false
  do-timestamp : Apply current stream time to buffers
                        flags: readable, writable
                        Boolean. Default: false Current: false
  device : Device location
                        flags: readable, writable
                        String. Default: "/dev/video0" Current: "/dev/video0"
  device-name : Name of the device
                        flags: readable
                        String. Default: null Current: "UVC Camera (17ef:4807)"
  device-fd : File descriptor of the device
                        flags: readable
                        Integer. Range: -1 - 2147483647 Default: -1 Current: -1
  flags : Device type flags
                        flags: readable
                        Flags "GstV4l2DeviceTypeFlags" Default: 0x00000000, "(none)" Current: 0x00000000, "(none)"
                           (0x00000001): capture - Device supports video capture
                           (0x00000002): output - Device supports video playback
                           (0x00000004): overlay - Device supports video overlay
                           (0x00000010): vbi-capture - Device supports the VBI capture
                           (0x00000020): vbi-output - Device supports the VBI output
                           (0x00010000): tuner - Device has a tuner or modulator
                           (0x00020000): audio - Device has audio inputs or outputs

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gstreamer-tools 0.10.35-1
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
Uname: Linux 3.0.0-13-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Sat Dec 3 14:33:54 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gstreamer0.10
UpgradeStatus: Upgraded to oneiric on 2011-11-30 (3 days ago)

[Shevek (r-launchpad-anarres-org)]

This works: mplayer tv:// -tv driver=v4l2:device=/dev/video1
This also works: gst-launch 'videotestsrc ! v4l2loopback' (built from github)

So the remaining thing that doesn't work is the stock plugin.