How to fix this strangely encoded video?

[PTRACER]

I have another DVD that has been encoded in a very odd way. It plays very slowly, with a running time of 3 hours 27 minutes 41.082 seconds and the audio is at a normal pitch, but is matched to the frames of the audio and is therefore very stuttery.

I have demuxed the VOB file into M2V and AC3 and the AC3 file plays at normal speed on it's own and sounds absolutely fine, but the video obviously plays very slowly.

I loaded both into VDub and it's telling me I need the video to run at 69.316fps to match the length of the audio. The length becomes 1 hour 29 mins 47.793 secs and it runs perfectly, except it's jumpy and needs to be re-interlaced somehow. It's supposed to be an NTSC video and it seems like it has duplicate frames throughout, in a regular pattern. Something like 2-2-2-3-2-2-2-3.

Can someone help me fix this video, using AVISynth, please? A short excerpt will be uploaded shortly...

[PTRACER]

Here is part of the video:

http://www.megaupload.com/?d=Z7V71MQX

[PTRACER]

I have now loaded it up into TMPGEnc and gone into the "Inverse Telecine" section.

Other than the first 7 frames, it seems like 1 frame is interlaced and then the following three are not, then the next frame is interlaced and the following three are not...and it goes in a regular pattern:

100000-1000-1000-100000-1000-1000-100000-1000-1000-100000-1000-1000-1000

So, it's like - 1 interlace frame followed by 5 non-interlaced, then 1 interlaced and 3 non-interlaced, etc.

Anyone have any idea on the best way to fix this, it seems very complicated and I have no idea how the video ended up like this in the first place

[manono]

Why send the AVI when the source is a DVD? Don't you know that we don't want to see something you've already processed when the chances are you don't know what you're doing?

Something like 2-2-2-3-2-2-2-3.

Not quite.

The framerate of the AVI you uploaded is 12.987fps. To remove all the dupes, Load TIVTC and:

Tdecimate(Mode=1,Cycle=30,CycleR=17)

To get it back to normal speed add:

AssumeFPS(29.97)

after doing the decimation. But since I don't know what you did to the VOB to create that AVI, I can't tell you how to treat the interlaced VOB. Forgive me for not paying any attention to your description, Perhaps:

TFM()
Tdecimate(Mode=1,Cycle=30,CycleR=17)

I know how someone would do that, but I don't understand why, unless he wanted to watch race cars in stuttery, jerky slow motion. Did you pay for this one, too? How about a VOB sample if you can't figure out how to handle the VOB yourself.

[PTRACER]

Why send the AVI when the source is a DVD? Don't you know that we don't want to see something you've already processed when the chances are you don't know what you're doing?

...because to send a portion of a VOB file, I either have to split it using a file splitter (which could cause problems with playing the file), or send an entire chapter, which would be 80MB in size and I wasn't sure whether people were prepared to download a file of that size. Not that it's anything more than a 2 minute wait with current broadband speeds being what they are...

Nevertheless, I'll upload one of the chapters anyway.

[manono]

...I either have to split it using a file splitter (which could cause problems with playing the file), or send an entire chapter...

Nonsense. Open the VOB in DGIndex. Use the [ and ] buttons to isolate a 10 second or so section. Then File->Save Project and Demux Video. Upload the resulting M2V somewhere after confirming it's not too large. We don't need a chapter to tell what's going on. 10-15 seconds of steady movement will be plenty.

[PTRACER]

Ah ha, thanks, that's a bit easier...My experience in the past has mostly been limited to VDub and TMPGEnc, unfortunately, so a lot of these tools are new to me.

Anyway, demuxed M2V should be coming in about 2-3 minutes...

[PTRACER]

You'll need to scroll halfway down the page and hit the big, green Free Download button:

http://www.filefactory.com/file/6575ad/

[manono]

I'm not sure why you were talking about interlacing. It was encoded as progressive 29.97fps and all frames are progressive, as near as I can tell. So, my original script still stands:

Tdecimate(Mode=1,Cycle=30,CycleR=17)
AssumeFPS(29.97)

I don't know for sure whether or not the audio will synch up when done. No way to know until reencoded and muxed, I guess. You can get a pretty good idea by comparing the lengths of the video and audio, if you know how to do it right.

[PTRACER]

Many thanks To re-encode this as a proper interlaced DVD, I'm assuming I need to add the following?

SeparateFields()
SelectOdd()
Weave()

[jagabo]

Wny would you want to interlace it? It's progressive, leave it that way.

[PTRACER]

I thought interlace would be required for smoother movement on TV's?

And by the way, with the script manono suggested, the audio doesn't match up with the video. The video ends up 12 seconds longer than the audio.

[manono]

I thought interlace would be required for smoother movement on TV's?

That's if it's interlaced to begin with. If shot on video, I suspect it probably was interlaced once upon a time. But what you showed me was progressive, and perhaps (probably?) deinterlaced. So, unless you want to fool around with MVTools and recreate the missing fields, reinterlacing it won't make any difference at all. Unless you use that script you posted. Then it'll really get messed up.

And by the way, with the script manono suggested, the audio doesn't match up with the video. The video ends up 12 seconds longer than the audio.

I was afraid that might be the case. However, that's not actually proof that they won't synch. Perhaps the audio is 12 seconds shorter than the video because it begins late or ends early. My suggestion is to go ahead and encode using that script and at 29.97fps and mux the resulting M2V with the audio. If they prove not to be in synch (and it's a progressive asynch, and not a constant one which can be fixed with the proper delay), then you can run the same M2V through DGPulldown set for whatever framerate makes it come out 12 seconds shorter.

[jagabo]

I thought interlace would be required for smoother movement on TV's?

If you had 60 progressive frames/sec then you could pull a field out of each and create 30 fps interlaced video for smoother playback. But you only have 30 frames per second.

And by the way, with the script manono suggested, the audio doesn't match up with the video. The video ends up 12 seconds longer than the audio.

Try changing the AssumeFPS(29.97) to AssumeFPS(30.0366) and then add a ChangeFPS(29.97) afterwards. The net result would be to throw out a frame every now and then to make the length match.

Or you could make the audio longer to match the video.

[PTRACER]

Eeek, nevermind.

Thanks a lot for your help, I think I've got it sorted!

[manono]

Try changing the AssumeFPS(29.97) to AssumeFPS(30.0366) and then add a ChangeFPS(29.97) afterwards.

A couple of hours later I was watching TV and out of the blue it hit me; to shorten it by 12 seconds you don't lower the framerate and then run DGPulldown. You increase the framerate. Funny how your mind keeps working on things "below the surface" so-to-speak. So I was wondering if the source had once been 30fps, but a quick calculation told me that wasn't high enough. Yours is high enough, but I'm not convinced that can be correct, because that can't be the original framerate. PTRACER says he solved the problem (but without saying how), so I guess I can put it out of my mind now.

[PTRACER]

I solved it using the code I was given:

TFM()
Tdecimate(Mode=1,Cycle=30,CycleR=17)
AssumeFPS(30.0366)
ChangeFPS(29.97)

The audio was out in certain places, but then was "in" again at another place. I noticed there was actually a jump in the audio, so I just put a gap in and added some artificially created white noise.

[manono]

Clever thinking. Thanks for the explanation.

[PTRACER]

On a completely unrelated note...if I wanted to demux a VOB into M2V and AC3, edit the audio in Adobe Audition and then remux the M2V and AC3 into either a VOB, or an MPEG2 file, what software do I need?

I've already got the files demuxed and edited, it'll just save me from re-encoding the video AND the audio and losing quality.

[manono]

Lots of ways to do what you want.

For demuxing a VOB without an IFO, I use DGIndex. Open the VOB and File->Save Project and Demux Video. That will give you the M2V and AC3.

For remuxing into VOB/DVD, I use Muxman. For making an MPG, maybe ImagoMPEG-Muxer. Imago can also make VOBs.