Deinterlace , Detelecine , or both?

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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okeygrak
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Deinterlace , Detelecine , or both?

Post by okeygrak » Wed Sep 12, 2007 5:43 pm

So I've done my research and know all about NTSC framerates, deinterlacing, detelecining etc.. but what I can't figure out ( using Handbrake .9.0 on OSX ) is which occasion to use both.

Quite a few of my DVD's were mastered in an interlaced format at 29.97, even though they were shot on film at 24 FPS. When I am encoding these movies, I have used the detelecine and deinterlacing options and still receive 29.97 FPS. If I use the detelecine option should I not be using the de-interlacing option ( or are these mutually exclusive? ), or is the optimal setting to both detelecine and deinterlace the source material?

fullerflyer
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Post by fullerflyer » Wed Sep 12, 2007 6:31 pm

...if you get a clear answer on that let me know, as I've asked the same question, too. Seems trial and error is the only way of knowing when to use which (or both)...

All I've understood regarding this issue is found here: http://handbrake.m0k.org/forum/viewtopi ... einterlace

hawkman
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Post by hawkman » Wed Sep 12, 2007 6:37 pm

If you detelecine you shouldn't need to deinterlace, as it reconstructs whole frames.

Detelecine is preferable to deinterlace, but only works on material that has been "hard telecined". (Soft telecining is automagically dealt with by HB.)

Google is your friend, and trial-and-error is your useful enemy, in determining which DVDs are telecined and which are interlaced 29.97fps material.

jbrjake
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Post by jbrjake » Wed Sep 12, 2007 7:03 pm

You need to use both on mixed content.

Step through the original video in Streamclip or something, or encode it once at 29.97 with no deint or detelecine and step through that, frame-by-frame.

If you see sections where more than 2 frames in a row are interlaced, then you need deinterlace on. (I suggest "Slow").

If you see sections where only 2 frames at a time are interlaced, and the surrounding ones are not...you need detelecine.

If one video has sections that need deinterlace AND sections that need detelecine, then turn on both.

The detelecine filter in 0.9.0 will not discard frames. 29.97 in, 29.97 out. But the extra frames won't be interlaced anymore.

Conner
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Post by Conner » Wed Sep 19, 2007 6:48 pm

jbrjake wrote: The detelecine filter in 0.9.0 will not discard frames. 29.97 in, 29.97 out. But the extra frames won't be interlaced anymore.
is there a time frame for when this might work properly (as in discard the extra frames)?

currently I'm skipping encoding material that needs to be detelecined with the hopes that handbrake might be able to handle it better 'soon' ...

Thanks

jbrjake
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Post by jbrjake » Wed Sep 19, 2007 8:01 pm

Conner wrote:is there a time frame for when this might work properly (as in discard the extra frames)?
I've been working on it every day for two weeks now. In fact, I logged onto the forum right now while a compile and test encode of it is running. It certainly won't be in the next release, 0.9.1, which is coming up soon to fix a bunch of 0.9.0 bugs.

Right now, my local code works great with stuff that's all hard-telecined...frames are successfully dropped. But I'm having issues getting it to work right with really mixed content. If I let detelecine see progressive frames with their soft-telecine flags, it doesn't properly discard them. If I make detelecine assume top field first for progressive and ignore the soft-telecine flags (basically what HB currently does when you set fps to 23.976), then I can get great output, but it combs when the pattern changes. And then there's getting the video duration perfect so the audio syncs up correctly....and making it play nice when deinterlace is used at the same time. And making it work right with b-frames. And making it work with MKV. It's still a ways off, is what I'm saying.

fullerflyer
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Post by fullerflyer » Thu Sep 20, 2007 4:45 am

jbrjake, thanks so much for your continued efforts! I can't wait to see this up and running.

Conner
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Post by Conner » Thu Sep 20, 2007 2:51 pm

jbrjake wrote:It's still a ways off, is what I'm saying.
I'm sure you'll beat it into submission (:

thank you sir, much appreciated!

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