[mythtv] Idea for interlaced playback.

[Ian Dall]

Bjørn Konestabo <bjornko at math.uio.no> writes:

> Dennis Tell wrote:
> 
> > I'm using a cheap msi fx5200 svideo out and it works with a 25hz
> > 720x576 output. I've attached my xorg.conf file if you'd like to try
> > it. I have deinterlacing turned off in mythtv, and am using opengl
> > sync. I have flicker filter and overscan set to 0 in nvidia-settings.
> 


I get good results with the following mode.

# Sync Timing PAL: Horizontal frequency 15625 Hz. H sync width 4 uS (58 dots). Vertical frequency: 25 Hz, Vertical Sync width: 192 uS (6 lines).
    Mode "720x576"
        DotClock 14.5
        HTimings 720 752 816 928
        VTimings 576 580 586 625
        Flags    "Interlace" "-HSync" "-VSync"
    EndMode


I don't recall exactly, but I found a real spec of a PAL signal to
work out the timings. While the vertical resolution is defined by the
number of scanlines, there is no counterpart for horizontal resolution
in analog tv, so the dotclock could change if the horizontal
resolution changed. The vertical sync width you have to work out as if it
is non-interlaced 50 hz.  

I also have deinterlacing turned off and have NVidia options:

   Option "TVStandard" "PAL-B"
   Option "TVOutFormat" "COMPOSITE"

YMMV. 

-- 
Dr Ian Dall				e-mail: ian at beware.dropbear.id.au