[mythtv-users] How I got great quality TV-out on my nVidia
MX4000
Jeroen Brosens
jeroen at fotoniq.nl
Tue Mar 8 07:45:24 UTC 2005
>> 5) In the MythFrontend Setup screen for TV Playback, enable:
>> - Deinterlace
>> - Mode: Bob (2x)
>
> Why de-interlace?
>
> Why not send the interlaced recorded signal you recorded back to the TV
> in the format that it expects to be played in, interlaced, with each
> field being shown for 1/59.94th of a second instead of combined with
> another field and only shown for 1/29.97th of a second.
>
> If you de-interlace you are essentially decimating any temporal (i.e.
> movement from one "scene" to another) down from 60/s to 30/s.
>
> b.
You probably don't know how bob works too well. Using bobdeint is the
*only* way to achieve the original field rate of the broadcast, as played
on a TV. Just outputting frames that are captured by the MPEG2 encoder
(which are a combination of the even and odd fields!) 1:1 using an
interlaced modeline leaves you with a setup that plays back at 30
f(rames)ps, whereas TV signal is 60 f(ields)ps (replace with 25 and 50
respectively for PAL).
Therefore, using bob is paramount for a smooth video playback. All other
deinterlacers as well as no deinterlacing (!) can't provide this.
Please do read this: http://www.100fps.com/, it offers excellent
explanations!
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