svideo resolution settings / xorg.conf

I have set up Ubuntu minimal install on Beagle xM, installed xfce:
sudo aptitude install xfce4 gdm xubuntu-gdm-theme xubuntu-artwork xserver-xorg-video-omap3
and adjusted das uboot so the default output goes via the svideo port.

Since I have a PAL tv at home, so set the setenv bootargs 'console=tty0 console=ttyS2,115200n8 root=/dev/mmcblk0p2 rootwait ro vram=12M omapfb.mode=tv:pal omapdss.def_disp=tv fixrtc buddy=unknown' and updated the uboot boot scripts by running the shell script.

Awesome, there is the desktop right there on my tv! However the desktop is too wide to fit in the screen (probably missing about 4cm either side and 2cm at the base of a 68cm tv). xrandr command gives the output minimum 720 x 574, current 720 x 574, maximum 720 x 574.

I tried to change the screen resolution by changing the bootarg to omapfb.mode=tv:600x500MR-24@50 and variations on this, also trying ntsc instead of pal, rerunning uboot script and rebooting to try each time. However all attempts just left me with a blank (black) tv screen.

Output from cat /var/log/Xorg.0.log | grep omapfb is:

ubuntu@omap:~$ cat /var/log/Xorg.0.log | grep omapfb
[ 18.166] Kernel command line: console=ttyS2,115200n8 console=tty0 root=/dev/mmcblk0p2 rootwait ro vram=${vram} omapfb.mode=tv:pal omapdss.def_din
[ 18.293] (II) LoadModule: "omapfb"
[ 18.299] (II) Loading /usr/lib/xorg/modules/drivers/
[ 18.302] (II) Module omapfb: vendor="X.Org Foundation"
[ 18.303] (II) omapfb: Driver for OMAP framebuffer (omapfb) and external LCD controllers:
[ 18.305] (WW) Error opening /sys/devices/platform/omapfb/ctrl/name: No such file or directory
[ 18.305] (II) omapfb(0): VideoRAM: 1616KiB (SDRAM)
[ 18.306] (II) omapfb(0): Creating default Display subsection in Screen section
[ 18.306] (--) omapfb(0): Depth 24, (==) framebuffer bpp 32
[ 18.306] (==) omapfb(0): RGB weight 888
[ 18.306] (==) omapfb(0): Default visual is TrueColor
[ 18.306] (--) omapfb(0): Virtual size is 720x574 (pitch 720)
[ 18.306] (**) omapfb(0): Built-in mode "current"
[ 18.306] (==) omapfb(0): DPI set to (96, 96)
[ 18.324] (==) omapfb(0): DPMS enabled
[ 18.325] (II) omapfb(0): Video plane capabilities:
[ 18.325] (II) omapfb(0): Video plane supports the following image formats:
[ 18.325] (II) omapfb(0): XVideo extension initialized

Q1 Line 18.306 says "Creating default Display subsection..." I presume this is referring to an xorg.conf file, but I cannot find one in any of its normal hiding places. What file is omapfb "Creating default Display subsection in Screen section" in?

Q2 I tried creating an xorg.conf file and putting a modeline in with a 680 x 540 resolution, but there was no change (xrandr still shows minimum available resolution to be 720 x 574). Is it physically possible for svideo to output a lower resolution or otherwise shrink the screen output so all the desktop can be seen on the tv?

Q3 The file boot.cmd contains the line 'setenv dvimode 1280x720MR-16@60'. Is there a setenv option for svideo?

Thanks very much if you can answer any of my demanding questions!

Hi Brett,
No answers for you unfortunately, but I just wanted to say I'm seeing
the same thing using NTSC s-video.


I think this is overscan, something desirable for video or multimedia output but not for desktop uses (the same rule applies to the svideo conection and pal or ntsc TVs, they are good for video and multimedia but not for desktop uses).

El 22/10/10 03:43, gtaubman escribi�:

Correct. All analog TVs apply overscan and therefore do not show the
full PAL/NTSC resolution. The only way to "fix" that is to tell
your X server to use less of the pixels available and leave a border
around them

e.g. on a PAL 720x576, you will want to use something like 640x480
to be on the safe side.

Even some LCD TVs apply overscan by default and some do not allow to
turn it off, so e.g. for 1280x720 you end up with a safe area of
~1180x650 or so...