i945GM and TV / TMDS-1 output

[Frédéric MAZUR]

Hello everybody,

I have some problems with the configuration of intel video driver with Xorg
server 1.3 or 1.4. 
I need to use 2 outputs, for example VGA+TV, or DVI+TV, or VGA+DVI. It works
very well, but the quality of the TV output and the DVI output is very bad.
My hardware material is an embedded card AAEON 9310 with intel 945GM
chipset. I use an additionnal card for SDVO-1 (which provides DVI output).

DVI (TMDS-1) Output : 

Output VGA and DVI are identical (clone mode), but on DVI output, certains
colors are flickering, and rather than having the correct color, I have some
little blue (RGB=255,0,0) flickering points. This happens only on dark
colors. When I try to get a screen capture, these points don't appear. I
don't have this problem on windows (using official intel driver), maybe
there is a bug into linux driver or settings missing ?


TV output :

The quality of output TV is very poor comparing with windows version (using
official intel driver). So, I suppose it's a problem of driver setting. This
poor quality results on diagonal lines on color transitions, for example
between blue and orange, which causes the picture flickering on these lines
(but it is not even flickering on DVI output). I think it's a scaling
problem between my screen (1024x768) and TV output (720x576 PAL). I'll try
to set 720x576 mode on TV output but it doesn't work.

First of all, I get list of available modes with xrandr :

Xrandr –verbose

Résultat 

	TV_FORMAT: PAL
		supported: NTSC-M       NTSC-443     NTSC-J       PAL-M

		           PAL-N        PAL          480p at 59.94Hz 480p at 60Hz

		           576p         720p at 60Hz    720p at 59.94Hz 720p at 50Hz

		           1080i at 50Hz   1080i at 60Hz   1080i at 59.94H
  1024x768 (0x62)   22.4MHz
        h: width  1024 start 1025 end 1088 total 1120 skew    0 clock
20.0KHz
        v: height  768 start  769 end  800 total  801           clock
25.0Hz
  800x600 (0x63)   14.2MHz
        h: width   800 start  801 end  864 total  896 skew    0 clock
15.8KHz
        v: height  600 start  601 end  632 total  633           clock
25.0Hz
  848x480 (0x64)   12.1MHz
        h: width   848 start  849 end  912 total  944 skew    0 clock
12.8KHz
        v: height  480 start  481 end  512 total  513           clock
25.0Hz
  640x480 (0x65)    9.4MHz
        h: width   640 start  641 end  704 total  736 skew    0 clock
12.8KHz
        v: height  480 start  481 end  512 total  513           clock
25.0Hz


I do not have "720x576" mode, I tried to add it with xrandr :

xrandr --newmode TEST 42.601 720 760 832 944 576 577 580 602 -HSync -VSync
xrandr --addmode TV TEST 

And I get the following error : 

X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  156 (RANDR)
  Minor opcode of failed request:  18 ()
  Serial number of failed request:  16
  Current serial number in output stream:  17


So, I suppose it means the graphic chipset doesn't support this mode for TV
output.
Is there a solution to force 720x576(PAL) mode onto the TV output of intel
945GM graphic chipset ? If not, is this a graphic display problem on TV
output that is known, if so, is there a solution to correct it ?

I have no problem with VGA output  ;)

Thanks a lot for your answers,

F. MAZUR.