[mythtv-users] Dual Head Problem with Intel Driver - Two LCD TVs Connected via DVI

lists_mythtv_users lists_mythtv_users at bigpizza.co.uk
Fri Aug 8 10:42:35 UTC 2008


Hello all,

I have an Intel DQ35JO motherboard with a Pegasus ADD2 dual DVI SDVO
card in the PCIe-x16 slot to give two DVI outputs.  I have a DVI to HDMI
connector on each DVI output and a pair of HDMI cables from the
connectors to a pair of LCD TVs.  With my current xorg.conf file I have
a cloned view of the desktop, i.e. the same desktop (at 1360x768 at 60) is
displayed on both TVs. 

My aim is to have a separate mythtv frontend process running on each
TV.  AFAIK it's not possible to do true multiseat without having
entirely separate video devices so I'm going to have a remote control
one of the frontends and a keyboard and mouse control the other.  I'm
working on the premise that I need a desktop that spans both TVs and
then start two mythfrontend processes with a different display number
passed to to each command.  However, I can't actually get a frontend
running on each display properly.  The frontend works fine when the
desktop is cloned on both TVs.  If I add the virtual option to xorg.conf
and use xrandr to place one screen to the right of the other then
mythfrontend starts up on one TV but the framerate drops to about 2fps. 
I can't seem to get an xorg.conf to create a spanned desktop either.  As
soon as I add a second screen to the serverlayout section and restart
the xserver I get an error during a memory operation.  I didn't take a
copy of Xorg.0.log but can post it if anyone wants to see it.  The low
framerate problem seems to be caused by the virtual option in xorg.conf,
once it was commented out the framerate returned to normal.  I'm using
the directfb decoder because I see tearing during horizontal pans when
using the Xvmc decoder.

Are there any fundamental issues with what I'm trying to achieve and/or
the hardware I'm using to achieve it?  I would eventually like to
connect a third TV to the box so I'm investigating suitable  PCIe-x1
graphics cards and so far Nvidia Quadros look like they fit the bill. 
Anyway, that's a slightly beside the point at the moment.

The xorg.conf is copied below.

Thanks in advance,

Steve.

# xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
EndSection

Section "InputDevice"
    Identifier    "Generic Keyboard"
    Driver        "kbd"
    Option        "CoreKeyboard"
    Option        "XkbRules"    "xorg"
    Option        "XkbModel"    "pc105"
    Option        "XkbLayout"    "gb"
    Option        "XkbOptions"    "lv3:ralt_switch"
EndSection

Section "InputDevice"
    Identifier    "Configured Mouse"
    Driver        "mouse"
    Option        "CorePointer"
    Option        "Device"        "/dev/input/mice"
    Option        "Protocol"        "ImPS/2"
    Option        "ZAxisMapping"        "4 5"
    Option        "Emulate3Buttons"    "true"
EndSection

Section "InputDevice"
    Driver        "wacom"
    Identifier    "stylus"
    Option        "Device"    "/dev/input/wacom"
    Option        "Type"        "stylus"
    Option        "ForceDevice"    "ISDV4"        # Tablet PC ONLY
EndSection

Section "InputDevice"
    Driver        "wacom"
    Identifier    "eraser"
    Option        "Device"    "/dev/input/wacom"
    Option        "Type"        "eraser"
    Option        "ForceDevice"    "ISDV4"        # Tablet PC ONLY
EndSection

Section "InputDevice"
    Driver        "wacom"
    Identifier    "cursor"
    Option        "Device"    "/dev/input/wacom"
    Option        "Type"        "cursor"
    Option        "ForceDevice"    "ISDV4"        # Tablet PC ONLY
EndSection

Section "Device"
    Identifier    "Intel Corporation Integrated Graphics Controller 0"
    Driver        "intel"
    BusID        "PCI:0:2:0"
#    Modeline    "1360x768"   85.50  1360 1424 1536 1792  768 771 777
795 +hsync +vsync
    Screen        0
EndSection

Section "Device"
        Identifier      "Intel Corporation Integrated Graphics Controller 1"
        Driver          "intel"
        BusID           "PCI:0:2:0"
#       Modeline        "1360x768"   85.50  1360 1424 1536 1792  768 771
777 795 +hsync +vsync
        Screen          1
EndSection

Section "Monitor"
    Identifier    "SONY TV"
    Option        "DPMS"
#    Option        "DPI" "100x100"
    Modeline        "1360x768"   85.50  1360 1424 1536 1792  768 771 777 795
 +hsync +vsync
    DisplaySize    697 395
#    Option        "DDC" "False"
EndSection

Section "Monitor"
        Identifier      "Samsung TV"
        Option          "DPMS"
#       Option          "DPI" "100x100"
        Modeline        "1360x768"   85.50  1360 1424 1536 1792  768 771
777 795
 +hsync +vsync
        DisplaySize     697 395
#    Option          "DDC" "False"
EndSection

Section "Screen"
    Identifier    "Screen0"
    Device        "Intel Corporation Integrated Graphics Controller0"
    Monitor        "SONY TV"
    DefaultDepth    24
    SubSection "Display"
        Modes        "1360x768"
#        Virtual        2720 768
    EndSubSection
EndSection

Section "Screen"
        Identifier      "Screen1"
        Device          "Intel Corporation Integrated Graphics Controller1"
        Monitor         "Samsung TV"
        DefaultDepth    24
        SubSection "Display"
                Modes           "1360x768"
#        Virtual        2720 768
        EndSubSection
EndSection

Section "ServerLayout"
    Identifier    "Default Layout"
    Screen        0    "Screen0"
#    Screen        1    "Screen1"
    InputDevice    "Generic Keyboard"
    InputDevice    "Configured Mouse"

# Uncomment if you have a wacom tablet
#    InputDevice     "stylus"    "SendCoreEvents"
#    InputDevice     "cursor"    "SendCoreEvents"
#    InputDevice     "eraser"    "SendCoreEvents"
EndSection



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