Fix MPEG2 Pulldown Flags

[Guiboche]

I have a vob file, and I opened it inside DGMPGDec. When I set "Force Film" option, there is still 1 interlaced frame for every 4th frame.

I'm assume this is a pulldown flagging issue, since if I choose to honor the flagging, the pulldown can be removed manually. But If I do that, then needs to be re-encoded.

Is there a way to fix the flagging without re-encoding the file?

[SLK001]

Is there a way to fix the flagging without re-encoding the file?

I've run across this before. The only way it could be reliably fixed was running it through an IVTC filter and re-encoding.

[Guiboche]

Does anyone know what causes this problem? Because the entire MPEG2 stream from the new Black Christmas DVD is like this from start to finish.

It's strange considering that you would think they would be in a perfect progressive environment that they wouldn't have such problems on new DVDs....

[manono]

I'm assume this is a pulldown flagging issue

No, it's not a flagging issue, as that implies it can be fixed by reflagging it somehow. It's an encoding issue. Your source is hard telecined (probably) - it was already telecined and then encoded for interlaced 29.97fps.

As SLK001 said, it has to be IVTC'd if you want to make it progressive again. I haven't seen the Black Christmas DVD, but that sort of thing isn't all that uncommon. They just used some cut-rate DVD production house to prepare the DVD. Plus, you're in Canada. I'll bet dollars to donuts that there's a different version for the US, and that it's been encoded as progressive 23.976fps. This sort of thing happens all the time to you guys.

If you weren't planning on reencoding it, then what does it matter to you? DVD players and TVs will play it fine (usually).

[Guiboche]

Alright. I didn't figure that the pulldown would be burnt in. Since on hard telecined sources, the mixed frame usually suffers from harsh colour and luminance artifacting that isn't apparent in the Black Christmas encode.

And the DVD actually doesn't playback fine on my TV. For whatever reason, the componenet source playbacks the 1 interlaced frame for every 4. But it doesn't do this on the S-Video connection.

Any of the DVDs with this same strange encoding on this problem on my TV.

[Nelson37]

Is your DVD set for Progressive playback? Usually, this will only work over Component, and in the case of a Hard Telecined film, Unless the player does a good-quality IVTC, would result in the type of playback you describe.

Try viewing frames in Vdub, are you saying there are 4 progressive, clear frames and ONLY ONE that shows interlacing? Usually it is 3 progressive and two interlaced. View the original DVD file, not the modified output.

[Guiboche]

Well that's the strange thing about my TV. It's a CRT HD television (not LCD or Plasma).

But it detects incoming film content. So any telecine errors you can see (like when you change chapters on a DVD, and there's 1 interlaced frame). And, pure hard telecine content, you can see where it keeps trying to update the order when it changes for each cut (such as music videos).

Again, over S-Video everything stays 100% interlaced.

And for the source, I'm talking about after you've chosen FORCE FILM for DGMPGEnc. There is 1 interlaced frame for every 4. So all it is doing is dropping ever 5th frame to create 23.976 from 29.97. Or so it seams.

There are no pulldown errors in the source. It's just burnt-in, but I though it was flagged....

[manono]

For whatever reason, the componenet source playbacks the 1 interlaced frame for every 4

So you reencoded it after all, using the Force Film D2V, and encoding it as Progressive 23.976fps? If so, then what did you expect? If you want to reencode, make your D2V using Honor Pulldown Flags, apply a full IVTC (Decomb, TIVTC, whatever), and then encode.

[Guiboche]

No I didn't re-encode it. I looked at the d2v file in VirtualDub.

And this:
For whatever reason, the componenet source playbacks the 1 interlaced frame for every 4

Was referring to playing back the original DVD on my television. I have both S-Video and Component hooked up to my TV. The component signal studders while the S-Video playsback fine. I can see this switcing back and forth between both signals.

[manono]

Then you have a horrible player. I'd suggest upgrading it immediately. You might turn off progressive scan (output 480i rather than 480p) and let the TV do the deinterlacing to see if it does a better job over component. It should look like what you see over S-Video, except better. There's no way you should ever see any interlaced frames when feeding into an HDTV.

[Guiboche]

It's not a progressive scan player. And it's set up full 480i over component.

[manono]

OK, you said this:

But it detects incoming film content.

You don't have incoming film content. You have incoming video content when you play a hard telecined DVD. Is this some kind of a setting you can change on the TV set? If it does that to hard telecine, then does it do that to real interlaced content, or is there a different setting for that? It sounds like it's doing its own Force Film (which is why I was confused earlier about whether or not you had reencoded the DVD), and it gives the same results as you get when you Force Film when you shouldn't. And if it's the TV set that sucks so badly, maybe you should buy yourself a decent Progressive Scan DVD player. If there is a video setting, and you set it that way for this Black Christmas DVD of yours, then it's going to just deinterlace it. That'll be better than what you have now - way better - but a decent cadence reading player would perform a real IVTC.

[Guiboche]

There is no setting I can change on the TV.

But it detects automatically if there is a pulldown in anything no matter where it's coming from. TV source or DVD.

So the reason I mentioned music videos, because those have changing telecine orders at every cut. And you can see where it keeps trying to follow and update at each cut, because the first 1 or 2 frames of a new cut is interlaced.

This is my TV
http://us.sanyo.com/entertainment/televisions/digital/index.cfm?productID=1240

[manono]

I feel your pain.

Music videos are tough for any TV or DVD player because they're edited as video, and don't pay attention to where the edits are made. Certain anime is tough for any TV or DVD player. Hard telecine is hard for some TVs and DVD players. About all I can suggest is for you to get a decent Progressive Scan DVD player that can handle these difficult DVD sources. I recommend the Oppos. Good luck.