[mythtv-users] Matrox G400 TV-Out (sorry large post)

Stephen Longhurst steve at longsteve.com
Tue Apr 27 06:45:47 EDT 2004

Hi all,

Apologies for the rather long post, but if anyone has the time to
offer any advice I'd appreciate it.

It looks to me like getting tv output on the Matrox cards is one of
the harder things one needs to do when setting up mythtv.  I've been
wrestling for a couple of weeks now to get the TV Out setup using my
Matrox G400, with both successes and failures.

Since the G400 offers a proper RGB scart connection (with a simple to
make cable), I'd have thought it would be top of lots of peoples
things to get working properly lists. Can anyone (and I'm begging
here) offer a set of instructions to getting a good mythtv setup with
tv output on a Matrox G400 card, pretty please?

Here's what I've successfully achieved so far:

1) MPlayer tv out using "mplayer -vo dfbmga:nospci -fs something.mpg"

This is fantastic, perfect picture, full screen, no tweaking or
settings needed changing at all to get videos to play fullscreen on my
TV.  When this worked, my spirits were lifted to think how good things
could be.

2) DirectFB frame buffer on the TV (console)

I've managed to get console output on the TV too using the DirectFB
stuff.  This took a bit of fiddling, including using the
matroxtv scripts from the mplayer source package.  These turn out of
be very helpful (check the mplayer source package in the TVout

3) Almost clone display of X windows on the TV.

This isn't so good yet.  I can get something on the screen, but the
picture is the wrong size and position, I loose quite a bit top and
bottom, and the sides are all wrong too.  I've tried playing with
fbset, but haven't got a good picture yet.  I can however play
something with mythtv on the tv like this, so there's promise here.

Question : Is there some way I can get the settings for fbset to get
the X screen correct?  I imagine something in mplayer knows how to set
things correctly, or something in the matroxtv script maybe?  Every
time I attempt to fbset one of the geometry settings, the whole screen
goes nuts, and it's typing blind to try and get it back, or reset when
that fails.

I'm probably going to continue trying to get the picture correct using
X for a while.  Having attempted to go down the QT/Embedded frambuffer
route with mythtv, I don't think that's going to get me anywhere soon.

Here's what hasn't worked yet:

1) Getting the X TV display properly configured.  I've seen various
examples of fbset commands, and even modelines for the XF86Config, but
nothing I try seems to work.  Can anyone offer advice here, for a PAL
TV setup?

2) A QT/Embedded framebuffer version of mythtv.

By the Lord Harry, this is a PITA too!  First of all, the QT/Embedded
build/install instructions seem to be inconsistent and unhelpful.  I
downloaded 3.3.1 and tried to build it, but there seem to be a raft of
gotchas.  I finally ended up with the thing built properly (I think)
with the correct set of flags like -thread and removing the -no-rtti
option and stuff.  I then tried compiling mythtv but it seemed to
insist on looking for the qt-mt library, when all that's built in the
qte libs directory is libqte-mt?  Symlinking libqt-mt to the qte one
seemed to do the trick and mythtv (cvs) will compile.  Although there
were some compile errors with screensaver-x11.cpp, so I switched it to
screensaver-null.cpp for now.

Now, when I try and run mythfrontend -qws, on my monitor, I do
actually get the frontend on the screen, although it's not centered
properly and is in a horrible 8bit colour mode.  When I set up the
framebuffer modules for the tv out, and set the QWS_DISPLAY=:/dev/fb0
(or indeed /dev/fb1), I do get something on the TV.  However, it's
simply a large screen rectangle on the display, about where the main
mythfrontend icons would be.  If I hit escape, I get another screen
box which looks like it should be the "are you sure you want to quit"
message and a yes/no selection.  I select yes and exit back to the
prompt with the console a bit screwey, but flipping virtual consoles
fixes this.

When I then read a bit more, and tried export
QWS_DISPLAY=matrox:/dev/fb0, I got QT/E complaining that the matrox
driver was not found.  After a bit of digging it seemed this wasn't
compiled before, so I managed to build it and then mythfrontend would
start again as before, but still only green rectangles on the TV :-(

So there you go! I'd got so far with setting up my new machine;
PVR-350 working, PVR-250 working, Nebula DigiTV working, lm-sensors
working, BIOS alarm wakeup using APCI, mythtv working fairly well on
my main monitor.  Only to have the most important part scuppered, the
TV output!

Finally, although I really want to get the Matrox working for me for
it's RGB scart potential, I've also got an NVidia 440 with TV-Out, and
the tv-out from the PVR-350 as fall backs.  Does anyone think these
are worth trying?  For an easy life, I'd settle for S-Video.

Thanks very much for your time,


Stephen Longhurst
steve at longsteve.com

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