Elisa displays video with greenish/purplish colors

[Loïc Molinari]

Binary package hint: libgl1-mesa-dri

Using Jaunty with Mesa/DRI drivers, Elisa displays video with greenish/purplish colors, it was working in Intrepid.

In Elisa, the video playback is done by the Pigment library which uses an OpenGL fragment program to do fast color space conversion from YUV to RGB. The fragment program uses 3 luminance textures containing the Y, U and V planes. For each rasterized fragment, the fragment program fetches the values from the 3 textures, computes the resulting RGB color, and stores it as fragment color.

The Mesa version used in Jaunty contains a bug making that fragment program output wrong colors. I just tried the last revision from the git repository and the bug is not there anymore. I'll try to bisect to get the right fix. It would be nice to get that back-ported to Jaunty because that's quite critical since Elisa can't be used to watch videos, which makes it a really useless media center. By the way, that bug is certainly breaking other programs using 3D acceleration through OpenGL and fragment programs.

libgl1-mesa-dri:
  Installed: 7.3-1ubuntu3
  Candidate: 7.3-1ubuntu3
  Version table:
 *** 7.3-1ubuntu3 0
        500 http://ad.archive.ubuntu.com jaunty/main Packages
        100 /var/lib/dpkg/status

[Loïc Minier (lool)]

20:45 < lool> loicm: Does it affect all hardware?
20:45 < lool> loicm: Are other apps than elisa affected?
11:02 < loicm> lool: It affects all hardware using DRI drivers, which include
               ATI and Intel, but not the NVIDIA proprietary drivers
11:04 < loicm> lool: Regarding other apps, I know that the OpneGL video mode of
               mplayer is broken as well, I didn't really tested other apps,
               but I guess Blender can be affected somehow

[Timo Aaltonen (tjaalton)]

Please test 7.4rc2 if it's fixed there.

[Loïc Molinari (loic.molinari)]

Just tried mesa-7.4rc2, it's fixed there.

[Pawel (pslomski64-deactivatedaccount)]

> Just tried mesa-7.4rc2, it's fixed there.

Will mesa-7.4rc2 get into Jaunty? As far as I know there's a big performance boost on Radeon cards:

http://www.phoronix.com/forums/showthread.php?t=16230

[Loïc Molinari (loic.molinari)]

The issue comes from problems regarding program and texture state validation in Mesa 7.3. After discussing with Brian Paul, he proposed to replace the file main/state.c from Mesa 7.3 with the one from Mesa 7.4, which fixed the issue.

Looking at the changes from 7.3 to 7.4 in that file, these 3 commits [1] [2] [3] have been integrated. Playing around with these commits and testing with Elisa, Pigment examples and Blender, I validated that these 3 commits combined together are needed to fix the issue.

Here is attached the patch to apply to the libgl1-mesa-dri Jaunty package.

[1] http://cgit.freedesktop.org/mesa/mesa/commit/?id=46ae1abbac6837d051c10b2e8b57eab3d4958ff4
[2] http://cgit.freedesktop.org/mesa/mesa/commit/?id=537d3ed6f3112fdf16fd853ada0e0bcc8bd83227
[3] http://cgit.freedesktop.org/mesa/mesa/commit/?id=de1caa550700ae38ff791c30f6d482f3efddebd0

[Loïc Minier (lool)]

Milestoning for final

[Martin Pitt (pitti)]

Timo will upload 7.4 to Jaunty today, since it is a bug fix only release.

[Martin Pitt (pitti)]

If you upgrade to 7.4, can you please add the entire changelog? If it changes a lot, then it seems very risky to me at this point in Jaunty.

If we opt to only backport the patch above, this has my +1.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mesa - 7.4-0ubuntu1

---------------
mesa (7.4-0ubuntu1) jaunty; urgency=low

  * New upstream release, merge from debian-experimental
    (LP: #330476, #347171, #349127)
  * Drop 103_rs600_support.patch, included in this version.
  * Drop 104_swrast_fbconfigs.patch, included in this version.
  * Add 103_bump_965_texture_limit.diff. (LP: #146298)
  * Add 104_fix_dri2_ext_tfp.diff. (LP: #324854)

 -- Timo Aaltonen <email address hidden> Fri, 03 Apr 2009 12:42:06 +0300