[mythtv-users] 720x480 interlaced modeline for nvidia/svideo

Wed Mar 29 17:28:26 UTC 2006

Yes, for the nvidia cards with TV-out you need to
fine-tune the flicker filter.  Too little and vertical
"lines" appear in the video, which seem to be related
to remapping the pixels horizontally.  (Also, graphics
flicker quite intensely.)  Too much and the picture is
blurred out.

Note also that the range for such variables as
overscan and flicker filter changed somewhere between
version 6111 and 7676 of the nvidia drivers.  The
range used to be 0-250 (or 255) and now it's basically
0-25, so old .nvidia-settings-rc files may act goofy.

If anyone's interested, here's what I've been able to
arrive at, after some grief:

1) HW setup:
  - P4 2.4GHz
  - PVR 500 (dual tuner)
  - nvidia GeForce4 MX440SE with S-video out (NTSC) <-
this is what I'm using for video.

2) Software setup:
  - Myth 0.19, compiled with --enable-opengl-vsync
  - nvidia drivers version 7676
  - kernel 2.6.8 (SuSE 9.2)
  - X is xorg 6.8.1

3) Excerpts from xorg.conf:

Section "Module"
  Load         "glx"
  Load         "type1"
  Load         "extmod"
  Load         "dbe"
  Load         "freetype"
  Load         "v4l"
EndSection

Section "Monitor"
  DisplaySize  160 120  # mm  <- a lie of course
  HorizSync 30-50
  Identifier   "Monitor[0]"
  ModelName    "M991"
  VendorName   "Toshiba"
  VertRefresh  60
  UseModes     "Modes[0]"
EndSection

Section "Modes"
  Identifier   "Modes[0]"
  Modeline      "640x480 at 60" 24.11 640 672 760 792 480
490 495 505
  Modeline      "800x600 at 60" 38.21 800 832 976 1008
600 612 618 631
EndSection

Section "Screen"
  DefaultDepth 24
  SubSection "Display"
    Depth      24
    Modes "640x480 at 60" "400x300" "320x240"
    Viewport   0 0
  EndSubSection
  Device       "Device[0]"
  Identifier   "Screen[0]"
  Monitor      "Monitor[0]"
  Option       "TVStandard"  "NTSC-M"
  Option       "ConnectedMonitor"  "TV"
  Option       "TVOutFormat"  "SVIDEO"
  Option       "TVOverScan"  "0.8"
EndSection

Section "Device"
  BoardName    "GeForce4 MX440SE"
  BusID        "1:0:0"
  Driver       "nvidia"
  Identifier   "Device[0]"
  Screen       0
  VendorName   "NVidia"
  Option       "NvAGP" "2"
  Option       "HWCursor" "true"
  Option       "RenderAccel" "false"
EndSection

4) The file ".nvidia-settings-rc.saved", which gets
loaded in the scripts after x is started.  (Using
"nvidia-settings
--config=/home/mythtv/.nvidia-settings-rc.saved -l")

#
# /home/mythtv/.nvidia-settings-rc
#
# Configuration file for nvidia-settings - the NVIDIA
X Server Settings utility
# Generated on Sat Mar 25 22:30:02 2006
#

# ConfigProperties:

ToolTips = Yes
DisplayStatusBar = Yes
SliderTextEntries = Yes
IncludeDisplayNameInConfigFile = No
ShowQuitDialog = Yes

# Attributes:

0/DigitalVibrance[TV-0]=34
0/SyncToVBlank=1
0/AllowFlipping=1
0/LogAniso=0
0/FSAA=0
0/TextureSharpen=0
0/ForceGenericCpu=0
0/CursorShadow=0
0/CursorShadowXOffset=4
0/CursorShadowYOffset=2
0/CursorShadowAlpha=64
0/CursorShadowRed=0
0/CursorShadowGreen=0
0/CursorShadowBlue=0
0/FSAAAppControlled=1
0/LogAnisoAppControlled=1
0/RedBrightness=0.232000
0/GreenBrightness=0.232000
0/BlueBrightness=0.232000
0/RedContrast=-0.072000
0/GreenContrast=0.024000
0/BlueContrast=0.024000
0/RedGamma=0.496000
0/GreenGamma=0.496000
0/BlueGamma=0.496000
0/TVOverScan[TV-0]=25
0/TVFlickerFilter[TV-0]=1
0/TVHue[TV-0]=6
0/TVSaturation[TV-0]=107
0/XVideoOverlaySaturation=4572
0/XVideoOverlayContrast=4013
0/XVideoOverlayBrightness=1
0/XVideoOverlayHue=331
0/XVideoTextureSyncToVBlank=1
0/XVideoBlitterSyncToVBlank=1

Note that TVOverscan is set to 25 and TVFlickerFilter
is set to 1 (both on a scale of 0-25).  Note also
sync-to-vblanks are set to 1.

5) MythTV 0.19 settings:
  - Deint on, using bob deinterlace (2x framerate).
  - Check "on" Use OpenGL Vsync in the TV Playback
menus.

6) Now when I play recordings or watch live TV, I have
the following:
  - Video scan lines for the fields are sync'ed to my
TV half the time.  But once sync'ed (either in or out
of sync) they stay sync'ed.  For example, if I pause
and then restart video, for about 1 second I see some
jittering due to some sync issues between myth and the
video card's TV out.  But after that 1 second, it is
either perfectly in phase with the odd/even fields or
out of phase by 180 degrees, and stays that way.  So
frequently, I hit "p" multiple times until I get
in-phase video.  Usually 2-4 tries and I'm there. 
When it works, it works beautifully, and stays.  So
it's as if Mythtv is syncing to either the even fields
or the odd fields but can't tell the difference
between them.  This is in contrast to myth 0.18, which
would slowly go in and out of phase over time no
matter what I did, and was really distracting.
  - It may be important to have "RenderAccel" set to
"false" in xorg.conf for this driver version/video
chip version.  This was critical for me after changing
to myth 0.19.  I had many crashes in 0.19 (curiously,
not 0.18) until I changed this.
  - Using the CNN ticker test, when this baby's in
sync the ticker looks marvelous and stays marvelous. 
(Until perhaps the next pause or skip.)

--- Robert Johnston <anaerin at gmail.com> wrote:

> On 3/13/06, Louie Ilievski <loudawg at comcast.net>
> wrote:
> > On Friday 10 March 2006 08:32, Robert Johnston
> wrote:
> > > So... you were saying...?
> >
> > This modeline and the settings you've given still
> do not do things properly.
> > Nice try though  :-)
> 
> Sorry, I forgot about the nvidia-settings tool.
> 
> In that, the "Flicker Filter" needs to be set to 2
> (That's 2/255) and
> Overscan to around 15 (Depending on your TV).
> 
> It's the "Flicker Filter" setting that has the most
> effect, however.
> --
> Robert "Anaerin" Johnston
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