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Problems balancing menu and video brightness settings
http://forums.linhes.org/viewtopic.php?f=17&t=9647		 Page 1 of 1
Author:  haertig [ Sun Apr 16, 2006 11:50 am ]
Post subject:  Problems balancing menu and video brightness settings
My problem (maybe specific to my system): MythTV menus require brightness settings to be very low, otherwise text is washed out, not sharp, and mostly unreadable. Setting brightness to minimum via nvidia-settings fixes this problem. But creates a second problem: watching actual video (not menus) things are way too dark.

Attempted solution: use nvidia-settings to set brightness way down for best menu display, use nvidia-settings XV overlay settings to re-brighten video.

I'm looking for some help either in (1) implementing the above solution, or (2) some other solution to my problem.

The above solution is theoretical at this point, I am having problems implementing it for testing. Specifically, my TV is hooked up to s-video output ("screen 1" in X) and my monitor is hooked up to VGA output ("screen 0" in X). Nvidia says overlays are only supported on screen 0.

From the NVIDIA documentation:
Quote:
The video overlay only works on the first display device on which you started X ... To work around this, you can either configure the video application to use the "Video Blitter" adaptor advertised through the XV extension (this is always available), ...

I can see this "Video Blitter" adaptor they mention:
Code:
$ xvinfo | egrep "(screen|Adaptor)"
screen #0
  Adaptor #0: "NV17 Video Overlay"
  Adaptor #1: "NV17 Video Texture"
  Adaptor #2: "NV05 Video Blitter"
  Adaptor #3: "NVIDIA Video Interface Port"
screen #1
  Adaptor #0: "NV17 Video Texture"
  Adaptor #1: "NV05 Video Blitter"
$

... but I have no idea how I'm supposed to make the application use this adaptor.

Is this adaptor setting something I can force via the environmental DISPLAY variable? I can find no documentation on how to force use of a specific adaptor.

Here's how I start the frontend (I'm currently using irxevent due to problems in lirc_client specific to my system - irxevent is my temporary workaround).
Code:
DISPLAY=:0.1 /usr/local/bin/irxevent &
DISPLAY=:0.1 /usr/local/bin/mythfrontend

Relevent sections from my xorg.conf file (other sections omitted for conciseness):
Code:
# distribution: Debian SID
# kernel:  2.6.14-1-686
# nVidia driver: 1.0-7676
# graphics card: eVGA nVidia GeForce4 MX4000 AGP 8x 64Mb; outputs: VGA, S-video

Section "Device"
        Identifier      "nVidia MX4000 (VGA output)"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Screen          0
        Option          "NoLogo"                "True"
        Option          "ConnectedMonitor"      "CRT"
EndSection

Section "Device"
        Identifier      "nVidia MX4000 (SVIDEO output)"
        Driver          "nvidia"
        BusID           "PCI:1:0:0"
        Screen          1
        Option          "NoLogo"                "True"
        Option          "ConnectedMonitor"      "TV"
        Option          "TVStandard"            "NTSC-M"
        Option          "TVOutFormat"           "SVIDEO"
EndSection

Section "Monitor"
        Identifier      "CRT"
        VendorName      "NEC"
        ModelName       "Multisync-70"
        Option          "DPMS"
        HorizSync       31-69
        # NEC states optimal at 1024x768@75Hz, set lower VertRefresh to force it
        # Actual VertRefresh specs for this monitor are 55-120
        VertRefresh     55-75
        # Set DisplaySize for 96 DPI at 1024x768
        # 96 DPI:  calculated (1024*25.4)/96  = 270 and (768*25.4)/96  = 203
        DisplaySize     270 203
EndSection

Section "Monitor"
        Identifier      "TV"
        VendorName      "Mitsubishi"
        ModelName       "60 inch rear projection TV"
        HorizSync       30-50
        VertRefresh     60
        # Set DisplaySize for 96 DPI at 640x480
        # 96 DPI:  calculated (640*25.4)/96  = 169 and (480*25.4)/96  = 127
         DisplaySize     169 127
        #Modeline       "640x480@60" 24.11 640 672 760 792 480 490 495 505
EndSection

Section "Screen"
        Identifier      "Computer Monitor"
        Device          "nVidia MX4000 (VGA output)"
        Monitor         "CRT"
        DefaultDepth    24
        SubSection "Display"
                Depth           24
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
EndSection

Section "Screen"
        Identifier      "Television"
        Device          "nVidia MX4000 (SVIDEO output)"
        Monitor         "TV"
        DefaultDepth    24
        SubSection "Display"
                Depth           24
                Modes           "640x480"
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default"
        Screen          0               "Computer Monitor"
        Screen          1               "Television"
        InputDevice     "AOpen keyboard"
        InputDevice     "Logitech mouse"
EndSection
Author:  sixosix [ Mon Apr 17, 2006 3:32 pm ]
Post subject:  Mythweb
Hi-

Don't worry about all those backend settings.

Open your mythweb.

mythweb

You can specifically set all brightness and color settings on every single channel in there.

Enjoy!
Mike
Author:  haertig [ Mon Apr 17, 2006 3:56 pm ]
Post subject:  Re: Mythweb
sixosix wrote:
You can specifically set all brightness and color settings on every single channel in there.
Thanks sixosix. Yes, I understand how to change per-channel settings at record time. I imagine I could compensate for lowered nvidia-settings brightness at playback time by boosting brightness at record time.

However, this would throw a wrench into something else. These recorded videos are not used only with a TV set. They are transcoded and sent to an iPod as well. So boosting recording brightness would seriously wash out iPod playback. Or so I would think. I would prefer to leave record-time settings as "normal" as possible and make any adjustments necessary at playback time, with nvidia-settings or similar (hopefully this makes sense).
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