Re: No 3D on iBook G4
Dear Michel,
On Nov 21 2013, Michel Dänzer wrote:
> On Don, 2013-11-21 at 01:16 -0200, Rogério Brito wrote:
> > I mainly need only to play videos (like lectures from Coursera and
> > other MOOC initiatives) and, honestly, I don't really care for 3D
> > graphics, but the video players that I tried seem to do (especially
> > when they choose an opengl backend).
>
> FWIW, it's definitely recommended to use XVideo over OpenGL for video
> playback on Apple PPC laptops.
I suspected that since my struggles with xine to get a DVD to be played with
xine, but I needed an expert opinion.
> > http://www.ime.usp.br/~rbrito/linux/debug-r300/1385003057-g4-linux-3.12-trunk-powerpc.tar.xz
>
> Looks like OpenGL is disabled due to the problem described in:
>
> https://lists.debian.org/debian-powerpc/2013/11/msg00045.html
To be honest, I didn't understand Rubén's intented message when he said
"¡Oh, I see!". I guessed (incorrectly?) that he had solved the problem, but
there were no further details...
> https://bugs.freedesktop.org/show_bug.cgi?id=71789
>
> Someone will need to investigate this upstream in Mesa.
Ah, OK, so I will try with a bitdepth of 16 as a workaround. For videos,
that should definitely be enough (especially for low bitrate videos).
But, well, I lied that I don't care about 3D at all: I would like to
participate in this course here:
https://www.edx.org/course/uc-berkeley/cs-184-1x/foundations-computer-graphics/1003
which says somewhere that the students will need an OpenGL 2.1 environment,
at least. But that can wait. The current studies are more important than
that one at this moment.
Still, I would love to help so that I can get that working in time for the
next offering (if I can be of any assistance).
> > After struggling a lot, I could get mplayer/mpv/vlc to play some
> > videos if I force XV to be used as the video backend, but, with mpv, I
> > get the following message:
> >
> > [vo/xv] X11 can't keep up! Waiting for XShm completion events...
>
> This looks like it just can't keep with decoding / displaying the video
> in realtime.
I didn't notice if frames were being dropped, but I will pay more attention
and report back what I find after I finish this e-mail and experiment with
the 16 bits per pixel.
> > While this is obviously based on impressions, the whole system feels
> > like everything is so slooooow regarding to graphics. :(
>
> One likely reason for the slowness is that you're disabling AGP with
> radeon.agpmode=-1. If your iBook isn't stable with the default AGP mode,
> try radeon.agpmode=1 or the other values.
I will try it as well.
I now remember that I reported a bug on kernel.org's bugzilla (to which you
replied) which was related to this notebook locking hard whenever I played a
video (it didn't matter the codec of the video).
> > Also, not really sure if things are connected to this graphics thing
> > or not, with Iceweasel 17, I can use things OK, but with Icewease 24,
> > I simply get a segfault right at the start. Reverting back to version
> > 17 makes it work again. Going back to version 24 makes it segfault
> > again. And so on. (Yes, everything with both clean and unclean
> > profiles).
> >
> > I am now, BTW, using qupzilla for posting this (via gmail). :)
> >
> > I suspect that newer versions of Iceweasel may be using something
> > related to WebGL and causing a crash?
>
> Not necessarily WebGL, but it might be related to OpenGL, yes.
Thanks for confirming that my impressions are, at least, not totally crazy.
IIRC, iceweasel 24 was also when Mike Hommey enabled gstreamer playing in
Debian. Not sure what gstreamer may be choosing as a backend to play HTML5
videos.
> One would need to look at a backtrace of a crash to tell though.
The only thing that I tried at that point was a simple strace, but I guess
that running iceweasel under valgrind/gdb would be the better thing to do.
Thanks for your always so nice replies,
Rogério.
--
Rogério Brito : rbrito@{ime.usp.br,gmail.com} : GPG key 4096R/BCFCAAAA
http://cynic.cc/blog/ : github.com/rbrito : profiles.google.com/rbrito
DebianQA: http://qa.debian.org/developer.php?login=rbrito%40ime.usp.br
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