[mythtv-users] How I got great quality TV-out on my nVidia MX4000
Will Dormann
wd at pobox.com
Sat Mar 5 19:35:39 UTC 2005
I recently added an nVidia graphics card to my Asus Pundit, in hopes of
improving the TV-out quality. The onboard SIS chip isn't bad, but I
figured I could do better. After tweaking settings for quite a bit,
here's how I achieved what I believe to be the optimal output. I have
an SDTV connected to the card via S-Video, FWIW. Some of these
settings may be redundant and/or unnecessary, but I'm just relaying all
the steps I've taken.
1) Install nVidia 6229 drivers
2) Recompile MythTV (0.16) with support for XvMC and OpenGL (via
settings.pro)
3) Modify your ~/.nvidia-settings-rc with the following values. You may
need to run nvidia-settings once to create this file initially.
0/SyncToVBlank=1
0/TVOverScan[TV-0]=125
0/TVFlickerFilter[TV-0]=1
0/TVSaturation[TV-0]=156
0/XVideoOverlaySaturation=4250
0/XVideoOverlayContrast=4096
0/XVideoTextureSyncToVBlank=1
0/XVideoBlitterSyncToVBlank=1
4) Modify the XF86Config file with the following:
Add to "Monitor" section:
ModeLine "coryntscpi" 28.6 720 760 824 912 480 484 492 525 interlace
Add to "Device" section:
Option "NoLogo" "true"
Option "HWCursor" "true"
Option "RenderAccel" "true"
Add to "Screen" section:
DefaultDepth 24
Option "TVStandard" "NTSC-M"
Option "ConnectedMonitor" "TV"
Option "TVOutFormat" "SVIDEO"
Option "TVOverScan" "0.8"
Add to "Display" subsection:
Modes "coryntscpi"
5) In the MythFrontend Setup screen for TV Playback, enable:
- Deinterlace
- Mode: Bob (2x)
- Use Video for Timebase
- XvMC Playback
That's it. With these settings, I get great image quality, great
motion, and great smoothness (no jitter in scrollers across the bottom
of the screen, for example). X CPU usage is between 1-2% during
playback. I don't see any interlacing artifacts in high-motion scenes.
The special modeline is required to get good resolution with Bob
Deinterlacing. With the standard modeline and 640x480 resolution, I
seem to lose about 1/2 of my vertical resolution when enabling Bob
Deinterlacing or XvMC.
You can temporarily add " --verbose playback" to the mythfrontend
command line to troubleshoot your playback. I see the following in mine:
------ This means XvMC is working ------
2005-03-05 13:56:48 XvMCSurfaceTypes::find(w 720, h 1, c 1, i 2, m 0,sw
0, sh 10
5, disp, p<= 105, 4800 <=p, port, surfNum)
2005-03-05 13:56:48 Trying XvMC port 105
2005-03-05 13:56:48 Found a suitable XvMC surface 0
2005-03-05 13:56:48 Using XV port 105
------ This means XvMC is working ------
------ This means Bob Deinterlacing is working ------
2005-03-05 13:56:48 XvMC will use bob deinterlacing
2005-03-05 13:56:48 Using deinterlace method bobdeint
------ This means Bob Deinterlacing is working ------
------ This means OpenGL Vsync + Video Timebase is working ------
2005-03-05 13:56:48 Using video as timebase
2005-03-05 13:56:48 Video timing method: SGI OpenGL
------ This means OpenGL Vsync + Video Timebase is working ------
--
-WD
More information about the mythtv-users
mailing list