Converting 29.97 NTSC (improper PAL transcode) to proper NTSC (with correct length)

[evilmonkeys]

So here's the deal:

I can convert fairly easily from NTSC to PAL and vice versa using VDub and BeSweet, but I have a problem with something related.

I have a 29.97 fps NTSC encode that was obviously transcoded from a 25 fps PAL source. The author did a simple frame shift and the program, although now NTSC compliant, runs at the shorter length and higher pitch of the PAL source.

Now it should be easy to demux the audio and correct the runtime and pitch, but is there a way to take the NTSC video and stretch it back to the correct length while maintaining a 29.97 or 23.976 framerate?

[Guest]

Who authored it and where did you get it?

[evilmonkeys]

It is actually the commercially available He-Man series (from the 80's). They (BCI) took the PAL masters and converted to NTSC retaining the run-time and pitch shift, but conforming them to NTSC standards. I have ripped them myself with the intent on converting them to the proper NTSC length and pitch.

I want to convert them to xvid/divx and get the proper timing down.

[Guest]

The author did a simple frame shift What do you mean exactly by "a simple frame shift"?

[evilmonkeys]

"A simple frame shift" was my way of saying that all they dis was convert the 25 fps source into 29.97 NTSC without affecting the pitch or run-time. Probably not the best way of putting it, but there it is.

[Guest]

And how did they do that? Field blending? Irregular pulldown?

You should post an unprocessed source sample because the answer depends on how it was converted.

[avdw]

DO NOT HELP HIM ! IT IS AN EVIL PIRATE !!!! :mad:

[Guest]

What is your evidence for that claim?

[evilmonkeys]

Exactly. I'll work on getting a sample upped this weekend (is a short sample of the raw mpeg2 video sufficient?). Maybe then we can figure out what they did. I thought it would be possible to just stretch the video to fit the original time allotted (easy to calculate from an NTSC to PAL source), but then it occurred to me that would probably cause some very unnecessary jerkiness from added frames.

I had a few of the original UK PAL releases from years ago and was able to successfully convert an episode from those (my first PAL to NTSC conversion, btw :) ), but I don't believe the entire series was ever released on DVD abroad. When BCI/Eclipse acquired the license for distribution in North America, they failed to obtain the original masters (an error they blamed on Hallmark Entertainment for supposedly destroying the masters after they created their PAL masters). Rather than converting the PAL source back to the properly timed and pitched NTSC version and then mastering the DVDs, they did what I call a "quick and dirty" conversion to NTSC standard, while retaining the overall length and higher pitch of the PAL source.

Ideally, the entire series would be available in PAL and then I could easily rip and convert them as I did before. But they apparently are not, and this is what I've got to work with now. I'm very sensitive to the pitch changes and they annoy me to no end. I've been wanting to do these conversions for the last couple years, but it always seemed to be more complicated then I though it should be. Recently, I've had an itch to give it a go again. However, this may be a bigger problem to correct then I originally thought....

[evilmonkeys]

Here's the samples as requested:

http://www.megaupload.com/?d=MJFV9992

Contained within the file is a one minute sample of the PAL source and the NTSC conversion. They were ripped directly from the DVDs and shrunk via DVD Shrink to save on file size. The samples were cut with Fast AVI Mpeg Splitter.

If someone can help me out with this, I would certainly appreciate it. What method did BCI use to convert and what can I do to change the NTSC conversion into a pitch and speed corrected NTSC version?

[Guest]

You've given me MPG files, yet you told me this was DVD material. Also, the NTSC one has a borked aspect ratio that you'd never find on a commercial DVD. I also don't want DVD shrinked files. So I am going to ask for source VOB fragments directly from your DVD rips. You can use DGSplit to make splits.

[evilmonkeys]

I can guarantee you these are from commercial DVDs. I'm not uploading illegally acquired files here as avdw has suggested.

I shrunk the files with DVD Shrink and then ripped the video using an old copy of TMPGEnc DVD Author (1.6, I believe). When importing DVD source files into the DVD project, it will save the video (and selected audio track) as the raw mpeg2 stream as a separate file. Newer versions save as a .dvddata file. This is the file I then split and uploaded. I'm not really sure why the file would show up as an odd aspect ratio. Under MediaInfo, the aspect is listed as 720x480 (4/3), which is correct. And the PAL sample is 720x576 (4/3) which is correct as well. Hmm.

If you really need the actual non-shrunk VOBs, I will rip them again and try the split with DGSplit, though I've never used that program.

[Guest]

As I said, I need the VOB fragments. DGSplit is easy to use. Open the VOB and select your chunk size. Then set stop after one chunk.

[evilmonkeys]

http://www.megaupload.com/?d=XM0R5C75

Here's the vob samples. The DVDs are not both authored to start at the beginning of the program, but I tried to include enough of the PAL opening sequence to compare to the NTSC version. Please take a look and let me know what you think.

[Guest]

The NTSC version is converted using field blending. Look at the available unblending solutions.

[evilmonkeys]

Will do. Thanks for the help.