Totem fails to play mp4 files originating from youtube

[Antoine-terracol]

In precise beta 2, Totem fails to plays mp4 files downloaded from youtube via Minitube or the Firefox DownloaHhelper plugin.
Totem does not crash, but displays a black screen.

As a result, totem-video-thumbnailer fails to create a proper snapshot to be used as a thumbnail for those videos in Nautilus (it aborts with a
"totem-video-thumbnailer couldn't process file: 'video.mp4'
Reason: Took too much time to process."
error message)

This is a regression as everything was fine in 11.10 using the same videos. Moreover, other media players such as VLC or SMPlayer have no trouble playing the video.

Steps to reproduce
- Download a video from youtube using minitube or the DownloadHelper Firefox plugin
- check that Nautilus does not display a snapshot of the video as a thumbnail
- check that Totem fails to properly plays the video, although it does not crash
- check that it is not the case in 11.10

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: libgstreamer0.10-0 0.10.36-1
ProcVersionSignature: Ubuntu 3.2.0-22.35-generic-pae 3.2.14
Uname: Linux 3.2.0-22-generic-pae i686
ApportVersion: 2.0-0ubuntu4
Architecture: i386
Date: Mon Apr 9 10:11:47 2012
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
SourcePackage: gstreamer0.10
UpgradeStatus: Upgraded to precise on 2012-03-29 (10 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Max Bowsher (maxb)]

Another way to obtain a video file to reproduce this:

$ sudo apt-get install youtube-dl
$ youtube-dl -f 18 lk5_OSsawz4

[gianluca.pettinello (g-pet)]

A workaround I just found:
go to /usr/share/thumbnailers
edit totem-video.thumbnailer
instead of using totem-video-thumbnailer use ffmpegthumbnailer -i %u -o %o after having installed it
then cancel the folder ~/.thumbnails/
Finally logout and login