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

[Steven Adeff]

On Fri, Feb 13, 2009 at 4:35 PM, Brad Templeton
<brad+myth at templetons.com> wrote:
> On Fri, Feb 13, 2009 at 04:29:19PM -0500, Steven Adeff wrote:
>> On Fri, Feb 13, 2009 at 4:22 PM, Brad Templeton
>> <brad+myth at templetons.com> wrote:
>> > 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?
>>
>> the doom9.org forums are *the* place to go to learn about all this
>> stuff.  from memory, motion estimation has nothing to do with
>> progressive/interlaced, as well, dct encoding (though not the
>> interlaced dependent version) can also be used for progressive video.
>> What settings you use for both, and how much affect they have can be
>> debated, but that is a better topic for the doom9.org forums =)
>>
>> you can also take a look at the mencoder scripts I wrote a while back,
>> they're on my mythtv wiki users page that's in my sig.
>>
>
> I am familiar with the mechanics of transocding and deinterlacing
> as would be talked about at doom9.    What I am asking about is what
> people have found as the best specific flags for mythtranscode.  I
> know how to do it with mencoder.
>
> For example, I found that when I run mythtranscode with kerndeint
> as a custom filter, the output was still interlaced according to
> mythtv's "Video scan" menu item on playback.   Is this the sort
> of thing they discuss over at doom9?    Again, my interest is only
> what specific settings people have used in mythtv to drive mythtranscode
> to good success, not advice on how to transcode.

ah, I see, can't help you there, I don't use mythtranscode, at the
time I didn't find it gave enough options to properly transcode for
archival purposes.


-- 
Steve
http://www.mythtv.org/wiki/index.php/User:Steveadeff
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