[mythtv-users] Pal/NTSC switching ?

[John]

Jean-Yves Avenard wrote:
> Hi
>
> 2009/9/21 John <reidjr at btconnect.com>:
>   
>> I have a working interlaced modeline for NTSC 720x480, and a 720x576
>> interlaced for PAL.
>>
>> I have the GUI and default Video set to 720x576, 25fps interlaced  and where
>> Video is 720x480 an overide to 720x480 rate 51 (modeline for 30fps
>> interlaced, on my nvidia card).
>>     
>
> Do you actually see 51 in the list of available modelines in MythTV ???
> What version of trunk are you running ?
>   
Mythbuntu daily trunk builds r21818
> If you see 51 it must be pretty old (from a trunk perspective). MythTV
> was amended to show the real rates available, not the nvidia
> DynamicTwinview rates (50, 51, 52 etc...)
>
>   
>> However when I play the two video types in myth, either as recorded TV, or
>> as a video using the Internal player, there is no modeline switching, with
>> the mode used being the last one set by xorg.conf, or xrandr.
>>     
>
> Are you sure the video being played is exactly 720x480 ? the custom
> resolution screen in mythtv is a bit limited, as the resolution must
> exactly match what you've entered.
>
>
>   
>> xrandr from a terminal will switch the VGA output between the two modelines
>> with no problem. I could set up a button on the remote to drive a script,
>> and then restart mythtv, but .........
>>
>> Any suggestions, or this is a bug/feature request  for interlaced modes ?
>>     
>
> unfortunately, interlaced refresh rates aren't well supported in
> MythTV, and if you have Dynamic TwinView enabled (the default) the
> list of refresh rates available is only populated with progressive
> rate (as mythtv is currently unable to make the difference between
> 30Hz progressive and 60Hz interlaced)
>   

> To get them available, you will need to disable Dynamic Twinview. In
> the screen section of /etc/X11/xorg.conf, add the line:
> Option      "DynamicTwinView" "False"
>
> >From there, the list of available rates will contain all those
> available, including interlaced rates..
>
> Jean-Yves
>
>   
OK thats fixed it, is so far as I can now see sane frequencies, 50 60 
and 64 (?).

However I cant get it to change based on the video resolution. If I set 
the gui to 720x480 and the default TV playback to 720x576, then it will 
switch to 50Hz when watching TV, and back to 60Hz with the GUI. However 
the video frame size seems to have no effect on the switching if i set 
any special sizes up.

I checked with mythfrontend -v playback, and the video resolution is 
seen as 720x480/720x576 as expected, but there is no xrandr switching 
based on the settings.


Thanks for your help.

John