This is a great post! Im looking forward to trying this. Thanks for sharing the knowledge.


Will Dormann wrote:

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 ------







-- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.6.2 - Release Date: 3/4/2005

_______________________________________________
mythtv-users mailing list
[email protected]
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

Reply via email to