XINE video output plugin for MATROX G200/G400/G450 cards *only*
=> $Id: README.syncfb,v 1.3 2003/01/05 13:11:53 guenter Exp $
* WHAT IS THIS PLUGIN ABOUT and WHY SHOULD I EVEN CONSIDER TO USE IT? :)
This xine video output plugin uses the so called SyncFB driver (from
the Teletux project) which provides special hardware features of
Matrox G200 and newer cards like hardware deinterlacing, scaling and
synchronization of your video output to the vertical retrace of your
monitor - just to name a few. The plugin makes all those features
available to xine and because all this tasks are done by the graphic
card there is no need for xine to do them in software -- so you save
precious CPU time which you may gonna need for other things. :-)
Ok ok -- why should you want to have your video output synchronized to
something called the vertical retrace of your monitor?! Well... :)
In order to have an optimal DVD playback the update of the image needs
to be syncronized with the vertical refresh of the screen. Otherwise
you will sometimes see part of frame n and part of frame n+1 during
playback of a movie. Resulting in tearing artefacts on moving objects.
When using this plugin the update of the screen is done during the
vertical retrace of your monitor and those tearing artefacts are gone
Also the SyncFB kernel module and this plugin totally by-pass XFree86
for anything else but some data gathering routines needed to place the
overlay at the right spot. So on some machines you will gain some
performance too because of the different way the SyncFB kernel module
handles your video output.
Last but not least, you may ask what's so special about deinterlacing?
There are already several deinterlacing methods available in xine and
why should you care about another one? Well (again)... ;-))
All current deinterlacers in xine are done in software and therefore
will cost you some CPU power. The SyncFB video out plugin will use the
hardware deinterlacing support of your graphic card, thus saving your
CPU power because everything is done by your GPU...
* WILL IT WORK WITH MY G200/G400/G450/... CARD?
So far the plugin and the kernel module itself are only being tested
on G400 cards by its developers thus we cannot tell about newer
or older generation chips.
Nevertheless we have received positive feedback that the SyncFB kernel
module and this plugin work fine with G450 cards too.
If you have got things working on older/newer chips, please let us
know about your success and we will place a note here... :-)
* AND HOW DOES IT WORK?
The SyncFB driver is a kernel module you will have to load that makes
a special device (e.g. /dev/syncfb) available which is opened by the
plugin and controlled with certain ioctl calls. Easy, isn't it? ;-)
That module is based on the mga_vid driver from Aaron Holzmann and was
advanced (and reworked) by Matthias Oelmann.
* OK I HEARD ENOUGH - HOW DO I INSTALL and USE IT? :)
Currently the Teletux project which maintains the kernel module seems
orphaned and therefore there hasn't been any progress nor release in a
fair amount of time. :( We will try to resolve this situation so that
the development continues again. As soon as there are any news on this
matter, this README will be updated accordingly. For the time being
you can still use the current Teletux SyncFB kernel module which works
just fine, so there is no need to worry. :-)
Back to the original subject. In order to install and use the SyncFB
kernel module, you *will* need a fresh CVS checkout of the sources
because the last official release is rather outdated.
This sounds more complicated than it actually is. You will only have
to execute the following two commands to get the sources in a sub-dir
called teletux. When you are asked for password, just press return.
cvs -d:pserver:email@example.com:/cvsroot/teletux login
cvs -d:pserver:firstname.lastname@example.org:/cvsroot/teletux co -P teletux
Now enter the directory teletux/syncfb, that's where the actual kernel
modul sources are located. Before you can compile the module, you will
have to change two lines in the Makefile itself to make it work.
In the second line, there is a phrase like "-I/usr/include" which you
have to change to "-I/usr/src/linux/include". In line seven, you need
to remove syncfbtv and syncfb_test from the OBJ list.
Now execute a "make" and the module will be compiled. Place the
resulting syncfb.o in your modules dir which is usually...
... and issue a "depmod -a" after it. That's it - the kernel module is
installed. To load the syncfb module, execute "modprobe syncfb" every
time you (re)start your computer. This will automatically create the
required /dev/syncfb device if you have devfs support, otherwise you
need to issue a "mknod /dev/syncfb c 178 0" once to create the
device yourself permanently.
Once the module is loaded, you can start xine with the "-V SyncFB"
option to use this plugin. xine automatically remembers the video out
plugin you last used, so you only have to use this option once too. :)
But don't forget, the module *always* has to be already loaded before
you start xine, otherwise xine will fallback to Xv/XShm or some other
available video out plugin.
* THE VIDEO IS JERKING - WHAT'S THE MATTER?!
Playing back video material that is mastered for e.g. NTSC can cause
this jerking if your monitor is not running at a refresh rate that is
a multiple of 30 (PAL: 25).
You can try to fix that by switching your monitor to the appropriate
refresh rates (e.g. 50/75/100 Hz for PAL, 60/90/120 Hz for NTSC). You
will need to add so called modelines to your XFree86 config to make
those modes available, if you don't already have them.
Here is is a short listing of some sample modelines. Please add only
those two lines (for NTSC and PAL) which exactly fit the screensize
you are running your X Server with. You need to add those lines to the
monitor section of your XF86Config file as well as include their names
in the screen section (subsection display of the color depth your are
USE THE FOLLOWING MODELINES AT YOUR OWN RISK. THEY COULD DAMAGE YOUR
MONITOR PERMANTELY - PLEASE TAKE CAUTION AND DON'T BLAME US. YOU HAVE
So much for the standard disclaimer. :)
Note: If you want to be on the safe side, generate your very own
modelines with an application like kvideogen for example.
Also the modelines may need some fine tuning for your setup. You
can use xvidtune (comes with XFree86) to do that.
Modeline "1024x768pal" 64.94 1024 1040 1216 1328 768 768 775 802
Modeline "1024x768ntsc" 54.32 1024 1040 1216 1328 768 768 774 802
Modeline "1152x864pal" 68.82 1152 1168 1384 1496 864 864 871 902
Modeline "1152x864ntsc" 80.93 1152 1168 1384 1496 864 864 872 902
none yet - might be added in the future
So before you run xine just turn to the appropriate refresh rate and
the jerking *should* be gone. (you may also want to have a look at the
XF86VidMode support included in xine which makes on-the-fly resolution
switching possible when fullscreen is toggled)
* WHAT SCREENSIZE SHOULD I PREFER?
Well. It is important that the screensize you choose for DVD playback
is exactly the same screensize you're starting up your X Server with
if you are not using the XF86VidMode extension which will properly do
the switching for you and take care that the plugin is updated
accordingly. So you shouldn't switch down to 1024x768 yourself if you
are running 1280x1024 because that gives you a virtual screensize
of 1280x1024 in a resolution of 1024x768 - and the plugin can't handle
that - and probably never will... ok... never say never. ;)
You may want to have a look at the XF86VidMode support in xine which
will enable on-the-fly resolution switching when activating fullscreen.
Now back to the question. A screensize of 800x600 should be it for
non-anamorphic DVDs because their resolution is 720x576 for pal DVDs
and 720x480 for ntsc ones. If you've an anamorphic DVD, you should use
a higher resolution - 1024x768 will be best because the image only has
to be horizontally scaled to get back to the original geometry of 16:9
which is easier to be done.
* WHAT ABOUT DEINTERLACING?!
Pressing 'i' during playback will toggle hardware deinterlacing. A
decrease in picture quality is a known side effect, yet you won't see
any artefacts caused by interlacing anymore. :-)
One more note, hardware deinterlacing uses BOB as deinterlacing method
and is totally independent from the software deinterlacing in xine. So
specifing a different deinterlacing method in your .xinerc won't have
any effect on this feature.
Nevertheless we are thinking about making software deinterlacing also
available as an option. It's on the TODO list... :)
* HEY! THE OVERLAY TURNS OFF WHEN THE WINDOW IS PARTLY OFF THE DESKTOP!?
That's done on purpose. It prevents possible yet harmless screen
corruption. And by the way - why would you want to see a movie just
* MY DESKTOP BACKGROUND IMAGE GETS CORRUPTED WHEN USING THIS PLUGIN!
Even though it doesn't look nice, it's nevertheless harmless. So no
need to worry about it. XFree86 is using your free video memory as
cache for certain things. Now when you use this plugin that part of
your video memory could also be used by the syncfb module. So your
image data cached there will be corrupted. Unfortunately there is no
way to avoid it. Yet, like stated earlier, it is truely harmless and
just a cosmetical side effect.
* THE XINE PANEL DOES NOT APPEAR WHEN I WATCH A MOVIE IN FULLSCREEN?!
Actually it does appear - you just don't see it. :) This is a side
effect of how SyncFB works. The X server can't display anything where
the actual overlay from SyncFB is being displayed because this area in
your video memory is constantly over written - so are the changes done
by your X Server (like a window graphic that is placed there).
This is just cosmetical and harmless, so no need to worry. If you want
to do something with the xine panel when the video overlay is taking
all your screen, just switch back to window mode and do what you have
to do and after that, back to fullscreen it goes. :-)
* KNOWN BUGs
+ the default_repeat config option is currently hardcoded to 0 because
any higher value than 1 will trigger a bug with the SyncFB kernel module
that results in a distorted picture (depending on video resolution)
[this bug is hard to trace, so don't hold your breath for now]
+ SyncFB overlay won't turn off when video window is minimized or
somehow else hidden.
[currently there is no way for the SyncFB plugin to know about the
state of the video window except if the original xine-ui hide function
is used to hide the video window... this will be fixed soon]
+ zooming feature is currently deactivated because it exposes a bug
with the SyncFB kernel module
[for now, don't expect this to be fixed soon - sorry]
+ the syncfb kernel module needs updating pretty badly
* WHAT IS ON THE TODO LIST?
+ fix above listed bugs in the SyncFB kernel module
+ make software deinterlacing available as an option
+ RGB support
(unlikely at the moment because there is no need for it)
+ check if the video source is not too big in terms of dimensions for
the video memory left (video memory - X reserved video memory)
+ bug fixes
+ more sanity checks
+ new features
* CONTACTS and FEEDBACK
Your first starting point should be this README followed by the FAQ. :-)
If you don't find your answers there or if you found a bug, please leave
a message on the xine user mailinglist (see the general README).
You can also reach the maintainers directly by mail (or you may consider
sending a message in bottle so we have some more time to find a good
excuse for the bug you may have found *grin*):
Matthias Dahl <email@example.com>
Joachim Koening <firstname.lastname@example.org>