[mythtv-users] Correcting for overscan with a PVR350

[Jerome Hettich]

>> The only problem is the X output looks too big to fit the screen so I
>> need to RTFM a little bit
>>     
>
> Still don't think it's possible to control overscan on the PVR-350's
> output. There is a possible hack listed on the ivtvdriver.org site,
> but the link is down.
>
> Nick
>   

Nick,

The latest version of ivtv (0.10) and the framebuffer driver seems to 
offers a means of overcoming overscan and displaying all of your 
xwindows session which works really well for me using my PVR350 and 
allows me to see the entire desktop and sorts out having to play with 
any overscan/positioning settings in myth to prevent it displaying in a 
non visible area of the screen - I'm not sure if this works using the 
PVR350 decoder as I use the xv support this driver offers to display 
using this card so I can use timestretch etc.

The steps I followed for fedora core 6 to tweak my box with a pvr350 to 
use this were:

step 1) determine the area of your output you can actually see on your 
tv- at the suggestion of Ian on the ivtv list I used fbset and trial and 
error to alter the width, height and positioning using a command eg:
# fbset -xres 630 -yres 500 -left 54 -upper 20 -fb /dev/fb1

step 2) use fbset to display the timing information as needed by XFree86 
as follows
# fbset -x -fb /dev/fb1

Mode "630x500"
    # D: 23.720 MHz, H: 29.650 kHz, V: 50.001 Hz
    DotClock 23.721
    HTimings 630 722 746 800
    VTimings 500 571 573 593
    Flags    "-HSync" "-VSync"
EndMode

step 3) add the mode from step 2 above into the "monitor" section of 
your xorg.cong

step 4) update the screen section of your xorg.conf to use the mode from 
step 3

step 5) restart X and enjoy being able to see all of your desktop and 
not having to play around with overscan or window size settings in 
mythTV anymore

For me the pvr350 and its xv support continues to make it an excellent 
card to use for non HD content with mythTV.

Jerome