[mythtv-users] Any hope for 1080i content at 1080i with nVidia?

John Veness John.Veness.myth at pelago.org.uk
Tue Jul 31 17:00:50 UTC 2007

Steve Smith wrote:
>   (2) If however you are doing some scaling then what you are outputing 
> isn't line for line the same as the signal so some form of 
> de-interlacing is needed. When does this happen?
>       One case is when you output a 16:9 format mpeg on a 4:3 TV. The 
> mpeg has 576 (for PAL) lines, but to get the right aspect ratio,
>       this is scaled to 0.75*576=432 lines. Now our fields don't match 
> up so we need to modify the picture with some form of deinterlacing.

Just out of interest, my old 4:3 Panasonic TV (now since died) had a 
mode where it would squash a picture vertically so that you were still 
getting 576 lines in a smaller physical space. If MythTV could output 
suitable video for that situation, it could theoretically not need to 
deinterlace. (I realise this doesn't apply to all 4:3 users).


John Veness, MythTV user

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