3:2 Pulldown - what do I need to remove the interlacing

[danalmsa]

Hi,

I am ripping the Shrek DVD to an XVCD and I have gotten it to a point that I am nearly happy with. The only thing that I would like to improve is the frame rate conversion.

Shrek is 100% NTSC Film and I was outputting it from Flask .6 to TMPGEnc 2.01 at 29.97. Now I understand all the problems with doing frame rate conversion plus I have read about how keeping it at 23.97 is the best, etc. I agree and all, but I wish to move it up to 29.97. I quit outputting at 29.97 last night cause it produces motion blur and I noticed the problem was the 4th and 5th frame.

So from what I have read, I set Flask to output at 23.97 and used TMPGEnc to encode at 29.97(I know this isn't recommended) but I did think that what I saw was a whole lot better. TMPGEnc duplicated the 4th frame and the blur went away. It did become a we bit jerky, but really unnoticeable.

The thing is, I have tried the 3:2 Pulldown, based on what I read to convert from 23.97 to 29.97, and it, as expected, produced 2 interlaced frames after the first 3.

My question is, how do I remove the interlacing from those frames? I tried selecting the De-Interlace, but that didn't do a thing, and I doubt it would since the source is progressive. If I select both filters(deinterlace and 3:2 Pulldown), which is applied first? Like I said, on my PC Screen I liked what I saw at Full screen when I did the unrecommended conversion (FLASK 23.97->Tmpgenc 29.97, no 3:2 Pulldown). If I leave the interlaced frames, would they show on my TV?(MPEG doesn't support interlacing, I think)

[stanwebber]

i suggest you scrap what you're doing then re-evaluate & re-learn. fact is, i dont see a single right decision in your encoding method as described

[danalmsa]

What is there to re-learn here? My DVD player does not support 23.97 FPS, so it's not a question of lack of knowledge, but of necesity.

I have re-evaluated and re-learned by reading a ton of posts(for the last 2 weeks) and burned a few tests CDs and like I said, I now output with Flask at 23.97, like quite a few people do here(others use DVD2AVI) and am trying to do a Telecine, which has been recommended on other posts when converting Frame Rates.

True, I have tried a few not so recommended methods, but I stated I knew those weren't recommended, but I accepted the consequences.

My question was not about my experiments, but on how to reduce the interlacing that 3:2 Pulldown creates when converting from 23.97 to 29.97.

It works great if I leave the Final Encoded Frame Rate at 23.97, but I need 29.97.

Thank You

[stanwebber]

assuming it is appropriate for the source the ONLY way to covert 100% ntsc to 23.976fps is inverse telecine: rebuild progressive or framerate decimation will output total crap. it is a hopeless proposition to try and salvage anything past that point. i'm trying not to be hard, but it's also obvious you have no firm grasp on the concept of 3:2 pulldown. you are seeing interlacing artifacts because they are supposed to be there: 3:2 pulldown applies a telecine pattern(typically 3 progressive, 2 interlaced) to dynamically create an extra 5th frame for every 4 encoded. here is my own pathetic diagram to illustrate

[kinneera]

I'll try to give a simple solution to this problem.

If the DVD is NTSC, it is telecined. This means that it is already at 29.97 fps. This means that you will see interlacing artifacts if you play it on a progressive screen (ie. computer monitor), but NOT on your TV. This is entirely appropriate. If your DVD player does not support 23.976 fps, then you shouldn't be doing ANYTHING. Just take the 29.97 fps out of Flask, and encode it as 29.97 in TMPGEnc.

If you want to reduce (restore, actually) the framerate to 23.976, you have two options. You can use the forcefilm option in DVD2AVI (which I strongly recommend over Flask if your encoder is TMPGEnc), or you can do an inverse telecine in TMPGEnc. Either way, the result will be progressive, in which case you (obviously) won't see interlacing artifacts no matter where you play it back.

[kinneera]

Oh, and I almost forgot... if you want to try for the best of both worlds, apply forcefilm or an inverse telecine to restore it to 23.976 fps. Then, apply the 3:2 pulldown on playback flag to the MPEG, which will make your DVD player telecine it back to 29.97 on-the-fly.

[danalmsa]

Sorry, but I think you have misunderstood my message, like I said, the source is 100% NTSC FILM(this may be my mistake, might not be called NTSC FILM, but just FILM), as in 23.97 FPS, not 100% NTSC as in 29.97. It is not telecined. There are no interlaced frames in my source. Inverse Telecine pulls from 29.97 to 23.93, so it is useless in what I'm doing. 3:2 Pulldown will get my 23.97 and turn it into 29.97, which is what I need to do. In that process it produces 2 interlaced frames. Again, I repeat my question, can I get rid of that interlacing on those two frames? If I can't, will it be noticed on my TV when I run the final VCD(which has to be 29.97)?

[danalmsa]

One more note, I do understand 3:2 Pulldown, I know it creates 2 interlaced frames after the first 3 progressive ones. I was just curious if some sort of post process could remove that interlacing, like blending those two frames after the pulldown was applied.

[homerpez]

So what you are saying is you want to take FILM rate and bump it up to 29.97?

First, I doubt you about your DVD player not supporting 23.976 as a playable VCD rate (MPEG-1 I assume), because it is standard. All the FILM-sourced VCD's I've ever made, I leave at FILM rate and they work nicely.

Do you mean that they speedup/slowdown or desynch?

Anyway, the only other way I know of, is to use a feature in TMPGEnc, which can make FILM rate into 29.97 rate. The fact is, if you are using MPEG-1, you can't use pulldown! That only works for MPEG-2.

If it is MPEG-2 (I forget what you said it was), then pulldown works (though there shouldn't be any interlace lines), and if there are interlace lines it's fine, because it's genuine interlacing (it will look fine on your TV).

Hope some of that was helpful!

[danalmsa]

I meant an XVCD, so MPEG-1. You don't have the 3:2 Pulldown on Playback option(Video Tab) available when doing MPEG-1, so I am using the 3:2 Pulldown filter on the Advanced Tab. That's the one that creates the 2 interlaced frames. I was under the impression, from what I have read, that MPEG-1(VCD or XVCD) doesn't support interlacing, so I thought that if my output is interlaced, it will look interlaced on my monitor. And I remember when I did my first VCDs, if I didn't remove interlacing, it would show on a TV Screen.

My player has been picky with 23.97, but I'll continue to do some tests until I make it work. I'm just paving my way to 29.97 just in case, cause it seems that's where I'm gonna have to go.

Kinneera recommended DVD2AVI, and I have used it, but I stick to Flask when the DVD has subtitles. It's not bad at all when you use the Reconstruct Progressive Images(From my understanding, it's similar to using FORCE FILM).

[homerpez]

I personally would try to do one of these three things vs. what you are doing (you apear to have tried the TMPGEnc feature I mentioned)...

1) Re-multiplex. A lot of the problems you can encounter with 23.967 framerate have to do with how the file is multiplexed, rather than encoded. I would suggest bbMPEG.

2) Re-encode. Take the original movie (assuming your original source DVD, TV cap or whatever, is 29.97 NTSC), run though DVD2AVI as full 29.97 res. Then on your re-encode, select "Interlaced" as the source type, instead of progressive. It MAY work in TMPGEnc, as it can process Interlaced source video. The problem is you're adding that many more frames to your encode, which will reduce quality, and I have to idea how the end product will look.

3) Does your player support SVCD's? Yes? Well, then here's one solution for you. When I encoded Shrek, I was able to make it full 480x480 res w/pulldown, 128k audio, and fit on ONE DISC. I used CCE to encode it, which might make it work for me, and not for you if you use TMPGEnc (poorer quality VBR). But it is 100% SVCD spec, and it worked for me.

I personally opt for SVCD now, since I know I can get away wth lower-AVG bitrate and still fit movies on 1 CD, but if your player only supports VCD/XVCD you may be stuck, if you can't leave it FILM.

I would definitely try re-multiplexing.

BTW: I would not use FLASK for anything. It encodes MPEG-1 using bbMPEG, which does not encode as well as either TMPGenc or CCE.


<font size=-1>[ This Message was edited by: homerpez on 2001-11-28 08:25:34 ]</font>

[danalmsa]

Thanks to everyone who has replied.

I guess that I'll continue to find a way to make 23.97 play. I was looking at some of my encoded 23.97 which played horribly and I think I have to mess with the GOP, it's at 1,5,2 , which I believe is incorrect. It should be 1,3,2 to put an I-frame every 12 frames.

Today before I came to work I encoded and burned a short part(and I mean real short) from Shrek at 23.97 and GOP 1,3,2 plus a few other options, and it looked ok on the player. I hope that was it.

Anyway, I am still interested in knowing, if I had to convert from 23.97 to 29.97 for a XVCD(MPEG-1) , if I could run it through a process to remove the Interlacing from the 4th and 5th frames that are generated when using the 3:2 Pulldown Filter in Tmpgenc.

[volswagn]

Just to add another $.02, I know you still want to find a way to do 23->29.97fps, but some thoughts:

As homerpez mentioned, I am sure your DVD player supports 23.97. They pretty much have to in order to ensure compatibility with today's DVD's. That said, if your player supports reading CD-R's, it should also support 23.97fps SVCD's. I wouldn't give up on keeping things at 23.97fps. I can't tell you how many coasters I made (before I got a bit smarter and just bought a couple CD-RW's) trying to get the settings right. Here's the settings that work well for me... I'm copying all the Enterprise series to SVCD from SVHS...

Capture in 720x480 huffy (you really only need 480x480) with no filters (I do all filtering post-capture)

TMPGEnc settings:

First start with the NTSC Film template, then go through and adjust the following settings...

Change Constant bitrate to 2pass variable (I usually use 2520top, 2100 average, 1700 min, which allows about 45-50 minutes at 23.97fps on an 80min CD).

Change GOP to 1,1,1 and make sure to select scene change detection...

On the screen with the MPEG fields, choose MPEG Standard and check all three boxes below that (I'm writing off the top of my head, so I don't recall exactly what they are). Also check soften block noise and leave at the defaults.

You're not converting from NTSC 29.97fps, so you don't need to do any filtering, but if you did, what I usually do is under source I mark my start point, then make an end point about 200 frames in and then go back and select inverse telecine for MOTION PRIORITY. I then let it run and check the result to make sure I'm getting all non-interlaced frames. If I'm not getting that, I go back to the filters screen and change the field order (From A first to B first or vice-versa). When I know what I've got, I go back and select my true end point in source, then go back to inverse telecine and select motion priority, perform while encoding.

What's very important is to use the highest quality setting when encoding. When I tried the setting below that there was just too much block noise for me. The highest setting really makes a nice picture...

These settings were really the only way I could get a good, clean SVCD conversion that played very smoothly on my DVD player. Flicker priority in inverse telecine produced motion problems and also changing the GOP to other settings produced too much phasing in the picture. I could see the image cycling through the group of pictures...

Hope that helps. Don't give up. I think you'll eventually get the 23.97fps playback and yet another upside is being able to hold more of the movie on each disc as well...

[homerpez]

Oh... you didn't mention that you messed with GOP settings. You really shouldn't. Usually the "default" settings on most progs are fine... That's probably your problem, actually.

volswagn, the reason I say that 23.976 should work for XVCD's is because the stanbdard for VCD 2.0 allows for playback at either FILM rate or 29.97 full NTSC rate. That's the standard of the format. So, if a DVD player supports VCD, it should also support 23.976 frame rate.

As for 23.976 rate SVCD, that's another story. SVCD really only supports 29.97 rate. To achieve that, you can either encode to NTSC directly, or you can encode at FILM rate, and add 3:2 pulldown on playback (to add frames to make it NTSC rate).

Unlike VCD, SVCD format by nature does not support 23.976 frame rate at all, you are supposed to use pulldown. If your player works with SVCD at FILM rate, you lucked out, because it really shouldn't.

[danalmsa]

Actually, just about everything with my XVCDs started to work fine when I modified the GOP to 1,4,2 which was based on what I had read. (Every .5 seconds = .5 x 29.97 = 15 frames = 1,4,2 GOP)

On my short test for Shrek( .5 x 23.97 = 12 Frames = 1,3,2) I saw that the 1,3,2 GOP allowed the Shrek clip to be played.

Then again, I could also attribute the success to the software I'm using to burn the VCD, which is now VCDImager with CDRDAO. I was using Roxio Easy CD Deluxe 5.

Could it be? Anyway, given the success, I'm gonna stick to the 23.97 framerate. It's weird though, I have stumbled across lot's of posts where people say their DVD Players can't play 23.97. Seems mine can, now

BTW, it definately can't play SVCD. I have an Aiwa XD-DV170.

[volswagn]

Homerpez said:
>>>As for 23.976 rate SVCD, that's another story. SVCD really only supports 29.97 rate. To achieve that, you can either encode to NTSC directly, or you can encode at FILM rate, and add 3:2 pulldown on playback (to add frames to make it NTSC rate). Unlike VCD, SVCD format by nature does not support 23.976 frame rate at all, you are supposed to use pulldown. If your player works with SVCD at FILM rate, you lucked out, because it really shouldn't.<<<

Sorry, I should've mentioned that (3:2 pulldown). By selecting the SVCD NTSC Film template first, TMPGEnc selects 3:2 pulldown by default. My DVD player doesn't play 23.976, it plays 23.976 with the 3:2 pulldown flag set (and thus converts to 29.97)...