Best Method of De-interlacing Mini-DV AVI files

[Dave2ic]

I’ve been evaluating various methods of de-interlacing Mini-DV AVI files, and wanted to get some feedback on my findings from those with a lot more expertise in this area than myself.

AVISynth does seem to offer the most in terms of video filtering tools. It’s difficult at times finding help on implementing the various filters when you’re not well verse on this sort of scripting, but it does seem worth persevering with.

I have tried a few of the de-interlacing filters in AVISynth, and I’d be interested in feedback on the following observations/questions:


1. MCBOB + NNEDI
I did read that was the best method for de-interlacing – if speed is not an issue (it is VERY slow). Results were very impressive, but I then discovered that I had a video with double the frame rate (which is exactly what bobbing is I later found out).

Having double the frame rate resulted in very smooth video, but there’s probably not much value in it for me because it results in very large files and I can’t really use the resulting file on video file sharing websites like Vimeo because they only accept input in 25 or 30fps.


2. NNEDI
As I only really wanted to de-interlace and maintain the existing frame rate, I tried NNEDI on it’s own and this gave me quality that was as good as MCBOB + NNEDI, but at around 10x the speed.


3. YADIF
I’ve read good things about YADIF, but the results I got weren’t as good as NNEDI. Looking at still images from the resulting output showed some straight lines looking a little jagged/blocky whereas in the output from NNEDI the straight lines were smoother.


Admittedly the quality I experienced with YADIF is possibly more to do with my settings rather than the filter itself, but I was more than happy with NNEDI on its own as a de-interlacing filter. The results I achieved with NNEDI seemed just as good as MCBOB + NNEDI, it ran much faster, and I wasn’t left with what, for my purposes, was an unnecessary doubling of the frame rate.

I’d be interested in any comment on my observations and any recommendations on other filters I may find useful.

[Soopafresh]

The best is a function called TempGaussMC . Slowwwwwwww. It also bobs, but adding SelectEven() to the end of your script will result in a 30fps file.

deinterlace_results.avi

[Dave2ic]

The best is a function called TempGaussMC . Slowwwwwwww. It also bobs, but adding SelectEven() to the end of your script will result in a 30fps file.

deinterlace_results.avi

Thanks for the recommendation. I tested out TempGaussMC just now and the results are impressive - if you have the time! However, on the material I tested (and bearing in mind I'm not bobbing) NNEDI came pretty close to TempGaussMC and ran 4-5 times faster.

So my conclusion is TempGaussMC if time is no constraint, but I'm pretty happy NNEDI for general use if I want faster output.

Thanks for the video link too. TempGaussMC leaves the others for dead in that test.

[poisondeathray]

Make sure you test on your particular source on particular sections. Some do better than others on certain sources. Sometimes you may use different deinterlacer on different sections

Also NNEDI has been replaced by NNEDI2, which offers some improvements

The 1 weakness of using NNEDI2 (or NNEDI) alone without another function like yadifmod, is you will sometimes see edges lines missing on thin graphics, titles and edges. I think the reason is that it is intrafield only when used alone (it doesn't look to the other field when deinterlacing to reconstruct frames), so it can drop 1 scan line.

TGMC applies a slight blur (it's adjustable) , to get rid of "interlace ficker/shimmer." So the side effect (besides slowness) is slight loss of detail. But you will find all the other deinterlacers will flicker to some extent on most types of content. So it depends on your tolerance and personal preferences.

The bottom line is look carefully and test all sources before committing, and there is no best deinterlacer

[ron spencer]

why do you want to deinterlace? it is losng information no matter how you slice it

[mr_smooth]

What are the option to remove the scan lines (wavey looking lines) during fast motions in DV (Any Flavor) video.

I plan to keep the original interlaced, i just want the output to be smooth and detailed for computer/HTPC consumption.

[poisondeathray]

What are the option to remove the scan lines (wavey looking lines) during fast motions in DV (Any Flavor) video.

I plan to keep the original interlaced, i just want the output to be smooth and detailed for computer/HTPC consumption.

If you mean for playback of the file only, you can activate deinterlacing upon playback.

Eg. in VLC , it's in the options. Set it to "bob" for full temporal resolution (double rate)

[Dave2ic]

why do you want to deinterlace? it is losng information no matter how you slice it

I want to deinterlace for playback on PC and uploading to video file sharing sites like Vimeo. And if I e-mail someone a video clip obviously I would want to deinterlace to compress it. I would leave it as interlaced in situations where it wasn't required like creating a DVD.

I know there are media players like VLC that deinterlace while playing, but I didn't find the results very satisfactory. In any case, if I distribute video material I don't want to have to depend on person I'm giving it to to play it back on a media player that supports deinterlacing.

[poisondeathray]

why do you want to deinterlace? it is losng information no matter how you slice it

I want to deinterlace for playback on PC and uploading to video file sharing sites like Vimeo. And if I e-mail someone a video clip obviously I would want to deinterlace to compress it. I would leave it as interlaced in situations where it wasn't required like creating a DVD.

I know there are media players like VLC that deinterlace while playing, but I didn't find the results very satisfactory. In any case, if I distribute video material I don't want to have to depend on person I'm giving it to to play it back on a media player that supports deinterlacing.

You can't have it both ways. You can keep 2 copies, an original interlaced, and a progressive deinterlaced version.

Using avisynth deinterlacing methods are much higher in quality, but much slower to process.

[Dave2ic]

Make sure you test on your particular source on particular sections. Some do better than others on certain sources. Sometimes you may use different deinterlacer on different sections

Also NNEDI has been replaced by NNEDI2, which offers some improvements

The 1 weakness of using NNEDI2 (or NNEDI) alone without another function like yadifmod, is you will sometimes see edges lines missing on thin graphics, titles and edges. I think the reason is that it is intrafield only when used alone (it doesn't look to the other field when deinterlacing to reconstruct frames), so it can drop 1 scan line.

TGMC applies a slight blur (it's adjustable) , to get rid of "interlace ficker/shimmer." So the side effect (besides slowness) is slight loss of detail. But you will find all the other deinterlacers will flicker to some extent on most types of content. So it depends on your tolerance and personal preferences.

The bottom line is look carefully and test all sources before committing, and there is no best deinterlacer

Thanks for your comments. You raise an interesting point regarding my evaluation of NNEDI. I was only looking at the quality of individual frames. If I understand correctly, NNEDI will give good results with generating individual frames from 2 interlaced fields, but because it doesn't look at the fields before and after the 2 that make up the frame it is filtering then the transitions between the frames will not be the best. Is this what you mean?

[poisondeathray]

Not exactly , but transitions aren't as good because of the shimmer or interlace flicker. It's still much much better than other deinterlacers, but compared to TGMC, it still has flicker.

While it's great to look at quality of individual frames, it's only during motion that the shimmer/flicker will be painfully noticable. This is usually from the residual artifacts and "jaggies" that result from deinterlacing.

NNEDI2 occasionally drops a line - you won't notice it on some sources, on others it will be very obvious (when the line occurs on a logo edge or a border). I assuming this is because it is intrafield only (this is just a guess, but the readme states that it's intrafield only). If you use yadifmod+NNEDI2, the line comes back.

There is no perfect deinterlacer, they all have little quirks and flaws, some pros, some cons

[Dave2ic]

You can't have it both ways. You can keep 2 copies, an original interlaced, and a progressive deinterlaced version.

Using avisynth deinterlacing methods are much higher in quality, but much slower to process.

I plan on just keeping the raw interlaced video (as a 'master') and only deinterlacing when required. Some of those AVISynth filters only run at about 0.5fps on my PC, which means it would take 4 days to deinterlace a single 1 hour MiniDV tape!

I do like the look of TempGaussMC, and it's only likely to be a few minutes video at a time that I'd ever need to deinterlace, so the slow speed is not much of an issue if I just leave it running overnight.

[poisondeathray]

I plan on just keeping the raw interlaced video (as a 'master') and only deinterlacing when required. Some of those AVISynth filters only run at about 0.5fps on my PC, which means it would take 4 days to deinterlace a single 1 hour MiniDV tape!

I do like the look of TempGaussMC, and it's only likely to be a few minutes video at a time that I'd ever need to deinterlace, so the slow speed is not much of an issue if I just leave it running overnight.

You can use faster deinterlacers, but the faster they are, the worse quality usually. These are tradeoff decisions you have to make.

Like the OP, I usually like something in the middle like NNEDI2 or yadifmod+NNEDI2, which are still several times faster than TGMC , but still many times slower than Yadif alone. Yadif is probably the fastest software based deinterlacer that gives decent results, you can easily run it in real time.

[Umen Pich]

Hey, where do I download TempGauss in the first place ?
By searching google one can find only discussions not the actual stuff.
Same thing here in this site.
thanks!

[jagabo]

http://avisynth.org/mediawiki/TempGaussMC

[Umen Pich]

http://avisynth.org/mediawiki/TempGaussMC

I see. My question was wrong. Is there a guide and a full package (DLLs etc.). Suppose I have a clean computer with avisynth only. Besides that single script what else do I need ? Is there an entry guide somewhere ?
Thanks again!

[jagabo]

That guide has links to all the other filters you need. See the "Required Plugins" section.

[Umen Pich]

Got it. Thanks a lot. 90 min DV cassette took 60 hours to deinterlace (which I don't mind). On a Intel Core 2 Quad Xeon X3360 OCed @ 3.4GHz. It uses only one core however.
The quality is very very nice, just in some cases - eg. roofs with many parallel grooves on them it happens so that the whole roof blinks at once. But I can leave with that.

[jagabo]

Got it. Thanks a lot. 90 min DV cassette took 60 hours to deinterlace (which I don't mind). On a Intel Core 2 Quad Xeon X3360 OCed @ 3.4GHz. It uses only one core however.

There's talk of some command line parameters that will speed it up. At the cost of slightly lesser quality.

https://forum.videohelp.com/threads/319816-Improving-old-VHS-What-to-expect?p=1981816&v...=1#post1981816

I found it to be roughly 5x faster.

The quality is very very nice, just in some cases - eg. roofs with many parallel grooves on them it happens so that the whole roof blinks at once. But I can leave with that.

Yes, that's the type of image that gives problems. Example with different deinterlacers:

https://forum.videohelp.com/images/guides/p1934885/stockholma_0-520_q3_yadif_mvbobmod_t...mca4_tdtmm.avi

[Umen Pich]

Actually that was the example (Stockholm) which I saw before starting to look for tempgauss. It gave me the idea of the different interlacers. Before I would never believe such a good output was possible. For now I am not going to look how to speed up the process. But I am sure my next camcorder must be able to shoot both 1080p and 720p. If you add to that 8+ Mega pixels stills. Add a good image stabilizer to that and if it costs around $1000 and the video noise is not that much... what else...

[Dave2ic]

There's talk of some command line parameters that will speed it up. At the cost of slightly lesser quality.

https://forum.videohelp.com/threads/319816-Improving-old-VHS-What-to-expect?p=1981816&v...=1#post1981816

I found it to be roughly 5x faster.

Thanks for this link, jagabo.

I tried out the code:

tempgaussmc_beta1u(1,1,0,0,0,0,edimode="--",SVthin=0.0,pelsearch=1)

However, I found the same problem getting jaggy diagonal lines that I mention in this post: https://forum.videohelp.com/threads/315725-TempGaussMC-showing-jaggy-diagonal-lines. If I changed the edimode to nnedi2, the problem went away - although at the cost of speed:




So these 'fast settings' with NNEDI2 still give me a 2.5x speed improvement over the 'default' settings (3.7 fps vs 1.5 fps) with the quality I'm looking for. Thanks!