I have my primary X monitor configured as TV out. When I play DVDs fullscreen, the picture gets pushed down vertically on the screen and the bottom wraps around to the top. I have used startx verbose 5 to get my settings and edited my xorg.conf appropriately. I also used gtf to generate a modeline.

Any thoughts on what I might be doing wrong?

Mandriva 2006
Nvidia MX4000

Thanks,
Charlie

It looks like your TV does not handle the colour system the video card is sending out. You either have a PAL or NTSC TV and the wrong system is output. I need more info. Which country are you located? Which driver are you using (nv or nvidia)? Does it only happen on DVDs or all the time?

I'm in the US. Here's my xorg.conf sections that pertain to the tv-out:

Section "Module"
Load "dbe" # Double-Buffering Extension
Load "v4l" # Video for Linux
Load "extmod"
Load "type1"
Load "freetype"
Load "glx" # 3D layer
EndSection

Section "Monitor"
Identifier "TVm1"
VendorName "Panasonic1"
ModelName "CT-27G12V"
EndSection

Section "Device"
Identifier "nvidiad1"
VendorName "NVIDIA Corp."
BoardName "NVIDIA GeForce4 (generic)"
Driver "nvidia"
BusID "PCI:1:7:0"
# COMMENT THESE OUT IF USING REGULAR MONITOR
Option "TVStandard" "NTSC-M"
Option "ConnectedMonitor" "TV"
##Option "TVOutFormat" "SVIDEO"
Option "TVOutFormat" "COMPOSITE"
# UNCOMMENT THESE OUT IF USING REGULAR MONITOR
#Option "DPMS"
EndSection

Section "Screen"
Identifier "screenTV1"
Device "nvidiad1"
Monitor "TVm1"
#Not sure if this works...DefaultColorDepth 24
# DefaultDepth 8
# DefaultDepth 16
DefaultDepth 24
# DefaultDepth 32

Subsection "Display"
Viewport 0 0
Depth 24
#Virtual 800 600
EndSubsection
EndSection

Section "ServerLayout"
Identifier "layout1"
InputDevice "Keyboard1" "CoreKeyboard"
InputDevice "Mouse1" "CorePointer"
Screen "screenTV1"
#Option "Xinerama"
EndSection

I tried setting the horz sync and vert refresh manually, but I've found that it works better if I don't specify them and let Xorg figure it out. At this point I'm learning about modeline, because fullscreen seems to have much more trouble with the picture rolling. I'm also wondering if modules like "glx" might be causing trouble... seems like simpler is better.

Thanks for your respone. I really appreciate your help.

Charlie

Try uncommenting the Virtual line. I wonder why you commented it. Also try putting 640 480. NTSC has only about 480 visible lines so any higher and the TV encoder might have trouble downscaling.

Also it might help if you reinstate the line VertRefresh 60 in the monitor section. It will also help sync the TV encoder to the graphics output. NTSC runs at 60Hz anyway.

Winno,

Thanks so much for your time. I tried your suggestions and they made things a little worse. The screen rolled more frequently and remained "pushed down" longer.

I didn't mention in my prior posts what Xorg detected. Here are the pertinent lines from my /var/log/Xorg.0.log:

(II) NVIDIA(0): TVm1: Using default hsync range of 28.00-33.00 kHz
(II) NVIDIA(0): TVm1: Using default vrefresh range of 43.00-72.00 Hz
(II) NVIDIA(0): Clock range: 12.00 to 650.00 MHz

(**) NVIDIA(0): Validated modes for display device TV-0:
(**) NVIDIA(0): Default mode "640x480": 25.2 MHz, 31.5 kHz, 60.0 Hz
(**) NVIDIA(0): Default mode "320x240": 12.6 MHz, 31.5 kHz, 60.1 Hz (D)
(II) NVIDIA(0): Virtual screen size determined to be 640 x 480
(==) NVIDIA(0): DPI set to (75, 75)

So, it seems to be determining things correctly.

Some questions:
1. The TV is about 8 years old, although it plays DVDs and video games fine (except from my Linux box). Should that be a factor?
2. Toying with the Overscan seems to be the single biggest factor in keeping the screen image stable. It seems the larger I make the overscan, the better the full-screen DVD performs, although it pushes my Linux desktop image off the edges, so I can't push it too far. I frankly don't understand why that would affect anything from the TV's perspective.
3. Is there any value to adding a mode or modeline? I tried a modeline entry generated on the X Free website, but that made things worse as well.
4. Can the Viewport setting help "push" the image to the top of the screen? The image seems to be starting 3-4 cm. from the top, which is probably the cause of the wrapping.

Again, thanks for your kind attention,
Charlie

Thanks for the info. Here's the answers to your questions. I'm not sure on how to answer them, but I'll try my best.

1. An old TV may have an effect, but 8 years ago from now is 1997. That's not terribly old, so it's not as likely to have problems with syncing with an off-60hz signal. I have a much older PAL-only (50hz) TV that has rolls everytime it gets fed an NTSC signal. You could try another TV to see if this works.

2. Increasing overscan reduces the blank lines and spreads the high frequencies (sharp detail) making it easier for the TV encoder chip. Not entirely sure, but that might be one possible explanation.

3. Adding a modeline may or may not help. I'm not really sure. There's a program called gtf (gtf.sf.net) where you could punch in the resolutions and refresh rate and get a line.

4. I don't think the viewport setting will work. It think it might be the "binding" of a video output to an Xserver. Try it, if it doesn't work, then change it back.

You can probably tell I'm a bit of a guesser when it comes to solving things. Other things to try:

Instead of the line Virtual 640 480, try Modes "640x480".

Nvidia's readme also says you can use 'startx -- -logverbose 5' to log the supported video modes to the Xorg logfile. To stop X, you could run 'init 3' as root.

I thought it would be possible that the card itself is jumpered or set via the video bios to PAL and the driver doesn't properly override it.

Try using Svideo if your TV has a connection. The behaviour might be different, and it's higher quality as well.

Hope something here helps.

Not sure, but this might be the problem..

I started up mplayer in verbose mode to play a DVD. Here's the output:

Starting playback...
VDec: vo config request - 720 x 480 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [xv] 720x480 => 720x540 Planar YV12 [zoom]
aspect: Warning: no suitable new res found!
aspect: Warning: no suitable new res found!

You may recall that my TV was autodetected as 640x480. I'm not sure what to do to remedy this, but I'm going to try a modeline for 720x480. I wonder what normal DVD players do with this inherent resolution mismatch.

I'll let you know how it goes. Thanks for the help.

Ah yes, it looks like mplayer isn't scaling the video correctly. It seems like it doesn't want to downscale and "lose detail". Did you try the full screen (-fs) option? You could also try using xine to play the DVD.

DVD's (and some video sources) don't use square pixels. Computer displays do. That's why 640x480 is used on regular 4:3 TVs. You can use 720x480 (with modeline generator), but text and computer graphics will be distorted because it will be "squashed" by the TV. It should be OK for video if it fills the screen. This is similar to a DVD player. It can squeeze all 720 pixels onto each scanline without scaling first.