[mythtv-users] overscan compensating display manager?

[John and Holly Klug]

Alex Halovanic wrote:
> "1296x724 at 60" 75.13 1296 1328 1608 1640 724 739 746 761
> "720p" 74.25 1280 1390 1430 1650 720 725 730 750 +hsync
>
>   ...
>
> If that 720p modeline works for you, you should be able to 'underscan'
> it fairly easily by simply changing the 1280 and 720 values to something
> smaller (by a factor of 8 of course).  It's a bit fiddly and involves
> restarting X a lot (and there are methods of changing the numbers to
> move it horizontally and vertically too) but you do end up with a a
> screen where any app you start will have its edges visible, not just
> mythfrontend.
Unfortunately, I have to battle the Nvidia driver which has a mind of 
its own.  I tried your suggestion of reducing the resolution, and my TV 
went to 1080i in both cases I tried:

xorg.conf:
 ModeLine "720p"   74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync
 ModeLine "700p"   80.00 1240 1272 1528 1560 700 714 721 736 +hsync +vsync
 Modeline "648p"   58.82 1152 1184 1400 1432 648 661 668 681 +hsync +vsync
   

 From Xorg.0.log:

(--) NVIDIA(0): Detailed Timings:
(--) NVIDIA(0):   1920 x 1080 @ 60 Hz
(--) NVIDIA(0):     Pixel Clock      : 74.25 MHz
(--) NVIDIA(0):     HRes, HSyncStart : 1920, 2008
(--) NVIDIA(0):     HSyncEnd, HTotal : 2052, 2200
(--) NVIDIA(0):     VRes, VSyncStart : 1080, 1084
(--) NVIDIA(0):     VSyncEnd, VTotal : 1094, 1124
(--) NVIDIA(0):     H/V Polarity     : +/+
(--) NVIDIA(0):     Extra            : Interlaced
(--) NVIDIA(0):   1280 x 720  @ 60 Hz
(--) NVIDIA(0):     Pixel Clock      : 74.25 MHz
(--) NVIDIA(0):     HRes, HSyncStart : 1280, 1390
(--) NVIDIA(0):     HSyncEnd, HTotal : 1430, 1650
(--) NVIDIA(0):     VRes, VSyncStart : 720, 725
(--) NVIDIA(0):     VSyncEnd, VTotal : 730, 750
(--) NVIDIA(0):     H/V Polarity     : +/+
  ...
(II) NVIDIA(0):   Validating Mode "720p":  ** My modeline matching EDID **
(II) NVIDIA(0):     1280 x 720 @ 60 Hz
(II) NVIDIA(0):     Mode Source: X Configuration file ModeLine
(II) NVIDIA(0):       Pixel Clock      : 74.250 MHz
(II) NVIDIA(0):       HRes, HSyncStart : 1280, 1390
(II) NVIDIA(0):       HSyncEnd, HTotal : 1430, 1650
(II) NVIDIA(0):       VRes, VSyncStart :  720,  725
(II) NVIDIA(0):       VSyncEnd, VTotal :  730,  750
(II) NVIDIA(0):       H/V Polarity     : +/+
(II) NVIDIA(0):     BestFit Backend for "720p": 1280x720
(II) NVIDIA(0):     Mode is valid.
  ...
(II) NVIDIA(0):   Validating Mode "700p":
(II) NVIDIA(0):     1240 x 700 @ 60 Hz
(II) NVIDIA(0):     Mode Source: X Configuration file ModeLine
(II) NVIDIA(0):       Pixel Clock      : 69.200 MHz
(II) NVIDIA(0):       HRes, HSyncStart : 1240, 1272
(II) NVIDIA(0):       HSyncEnd, HTotal : 1528, 1560
(II) NVIDIA(0):       VRes, VSyncStart :  700,  714
(II) NVIDIA(0):       VSyncEnd, VTotal :  721,  736
(II) NVIDIA(0):       H/V Polarity     : +/+
(II) NVIDIA(0):     BestFit Backend for "700p": 1920x1080      ***NOT 
USEFUL***
(II) NVIDIA(0):     Mode is valid.
 ...
(II) NVIDIA(0):   Validating Mode "648p":
(II) NVIDIA(0):     1152 x 648 @ 60 Hz   *** Multiples of 8 wanted by 
driver supposedly ***
(II) NVIDIA(0):     Mode Source: X Configuration file ModeLine
(II) NVIDIA(0):       Pixel Clock      : 58.820 MHz
(II) NVIDIA(0):       HRes, HSyncStart : 1152, 1184
(II) NVIDIA(0):       HSyncEnd, HTotal : 1400, 1432
(II) NVIDIA(0):       VRes, VSyncStart :  648,  661
(II) NVIDIA(0):       VSyncEnd, VTotal :  668,  681
(II) NVIDIA(0):       H/V Polarity     : +/+
(II) NVIDIA(0):     BestFit Backend for "648p": 1920x1080
(II) NVIDIA(0):     Mode is valid.


Notice that BestFit Backend is 1920x1080 for 1240x700 and 1152x648, so 
only the 720p specified by EDID will actually go into 720p on the TV.