[mythtv-users] Speaking of transocding: 1080i deinterlace?

[Brad Templeton]

On Fri, Feb 13, 2009 at 01:14:04PM -0800, David Brodbeck wrote:
> On Fri, February 13, 2009 1:05 pm, Brad Templeton wrote:
> > c) Reduce the resolution to 1280x540 or even 1080x540, giving
> >             up half the lines and of course deinterlacing.
> >
> >         Do we use a different filter than above?  Perhaps "onefield"
> >         is simpler or is it better to stick with kerndeint or
> >         linearblend?
> 
> I haven't tried it, but assuming the goal is to avoid comb artifacts, I'd
> use onefield for that.  It'd be much faster, and deinterlacing filters
> almost always cause some loss of sharpness, so I avoid using them when
> possible.

Well, obviously downrezzing from 1080 lines to 720 or less will cause
loss of sharpness, I don't see the deinterlace filter adding more.
Presumably onefield gives you a 30 fps progressive result.   Do
the other filters also give a 30fps result or do they generate a 60fps
result, or does only bob (which is the best playback filter) do that?

But I am interested to hear what people have tried.   In particular,
is it correct that interlaced dct encoding and mostion estimation are
only for interlaced video (and presumably they do nothing on progresive
video or even more ideally would not be applied by mythtranscode).
If you are deinterlacing first, you would not use them, right?