NTSC <-> PAL: Request for D3s7 & Discussion

[Yayita]

I am very determined to help move the Big 3/4 software bundle to provide "real" backups of PAL to NTSC and NTSC to PAL.

Zeul with its latest release of Numenu4U has given a giant leap in that direction.

So far I have been able to create real backups of the main movie using original audio and original subtitles, a "real" backup.

I am going to prepare a guide very soon, so that people can follow it. The main change from the big 3 is that the encoder has to be changed, you need to use procoder. The problem with CCE is that the available conversion solutions are unacceptable. I'll refer to the PAL->NTSC conversion as I live in NTSC land.

Solution 1: Extend the movie, use all the original frames and reproduce them at 23.97 pulled-down at 29.97. CONS: the movie grows by 4.3% (25/23.97) a 120 min movie ends up being 125 mins, go to IMDB, and you think you have a director's cut with extra scenes :mad:; but no, you just have crappy encoding. Plus you have to change the audio, and strecth it, that will change the pitch of the audio, you would then need to correct that with an audio software like nuendo or sonic foundry. In conclusion there is no such thing as PAL or NTSC audio, only NTSC video; this solution is unacceptable.

Solution 2: Drop the 25th frame, so that the you have the same duration of the video. The good, is that you have the same duration, but the video quality suffers from those missing frames.

*** Note that Zeul is using CCE in Numenu4U, but solutions 1 and 2 are not only acceptable for menus, but necessary to ensure menu buttons (BOV) work propperly.

So for "real" video standard conversion backups we need to use procoder. Many in these forums have concluded that it provides the best video standard conversion. See for example,
http://forum.doom9.org/showthread.php?s=&threadid=45459, written by someone who obviously knows much more than me about the subject. In my case, going from 25 to 23.97 results in a very good quality because as easy2Bcheesy says in the above link, when going from more to less fps procoder blends (merges) frames/fields, and it does a good job at it.

So now to the Big3/4 automation. Somebody would need to create a little batch utility to create the procoder encoding preferences files. For the mean time we can do this manually.

So D3s7, I think you can add this standard conversion option. I may be way out of line, and only shouting out my ignorance, but I think that this should be easily implemented in Scenaid. Assume that the video and the subtitle assets have changed video standard and create the script to put all the assets in place. No change in time necessary. I have done this by hand in scenarist and it was not terribly burdensome.

If this is implemented, we would still need to implement the change in video standard when we do the final step of updating the ifo files from original to authored. Honestly, I do not know how hard this last part would be.

Anyhow, I believe that full "real" NTSC<->PAL backups are not far away.

Sorry for the long post. And wait for my guide: "Real backups PAL<->NTSC for Big 3 users (main movie only)"

[Zeul]

I understand many peoples opinion on procoder. However, there is one thing that you are forgetting. Unlike CCE you cannot specify the chapter point in Procoder. No matter you may think, but by not specifying the exact location of the chapter (for I frame insertion) then the scene location written into the script will be based off the original, the new WILL be different. That is very bad for subs & BOV (inc menus). There will be multiple sub overlapping warnings, and worse occasionally scenarist will 'forget' that the scene exists (if a sub has crossed over it) and will actually crash on the linking.
In summary, Procoder can be very useful but not for automation at the moment, where by we must stick with CCE.

Zeul

[influenza]

Or encode everything on cell level :). Never messed with procode btw

[Yayita]

Zeul,

In the spirit of dicussion, not of correcting you, because I obviously know much less than you...
The change in video standard means that you can not have the same frames. That is even if you could control the I-frames, it would be a different number.
So with chapters, that need an I-frame, you could be off at most a whole GOP, about 1/2 a second. In the case of subtitles, since they are written in real time code;ff, you are going to be off at most a couple of frames, which is completely imperceptible.
Although I can imagine subs being off a couple of frames could ruin the menu... But in the main movie, this should not be a problem.

[D3s7]

Actually, in the main movie it's just as important..... especially for BOV titles...

We do understand however that the frame locations are different, they still need to exist...

I currently have a number of people complaining about subs crossing scenes, import issues, highlight issues, .5sec duration errors and most of these all boil back to incorrect Scene/chapter locations generally caused by encoding before ScenAid is launched.

I have considered adding the option for format conversion however, you have to remember that our utilities are primarily for backup of DVD's you currently own and last I looked, it's not exactly an easy task to purchase a PAL dvd in NTSC land :)

If the demand is high enough I may look into this but it's currently at the bottom of my list TBH

[influenza]

And honestly I think it`s mainly the NTSC crowd that`s interested, since in PAL land we have players and TVs that are capable of playing both PAL and NTSC. :cool:

[Yayita]

Zeul and D3s7,

Okay, so the inability to place the I-frames makes my proposed solution not feasible for menus. So, Zeul, please note I edited the original post, and now say that CCE, is not only acceptable but necessary for menus.
So D3s7, that means that my proposed solution for the moment, does not work for BOV in movies. But you have to admit that currently even without video standards conversion VOB support is in its infancy. And even if BOV support is not possible for now, that should not stop Scenaid from providing this possibility (video standards conversion) assuming video and sub assets have changed format.

Cool movies never make it to the other video standard, people travel, and there is international internet buying. The demand for video standards conversion exists. Just look at these posts, incomplete list only from the Big 3 forum:

http://forum.doom9.org/showthread.php?s=&threadid=86350

http://forum.doom9.org/showthread.php?s=&threadid=59055

http://forum.doom9.org/showthread.php?s=&threadid=84705

http://forum.doom9.org/showthread.php?s=&threadid=60209

http://forum.doom9.org/showthread.php?s=&threadid=58894

http://forum.doom9.org/showthread.php?s=&threadid=58818

http://forum.doom9.org/showthread.php?s=&threadid=55002

http://forum.doom9.org/showthread.php?s=&threadid=84705

So if this option is not too hard to implement, then it would be great to see it in Scenaid. :cool:

Can I email you D3s7?

[D3s7]

No offense but you need to re-read my previous post :)

It's more then just BoV titles... it's any/all titles that require close scene times...... Insomnia for example won't even mux unless the chapter locations are RIGHT on.....

I'll keep my options open to the idea of adding a format conversion however if I do, it will be with CCE in mind and probably won't be for a long time..... too many other requested items are on the list

[influenza]

There are already options to do this yourself. If we're talking about format conversion of the video. As long as it's something that can be done through avisynth you can do it yourself. In doitfast4u you can change things in the avs editor to suit your needs. Any audio conversions that might be needed nmust be done by hand of course before using scenaid.

EDIT: hmm I might be thinking about uit too easily. Scenaid might get confused by NTSC assets and a pal ifo. Wel you can always do things the old fashioned manual way :)

[manono]

Hi-

I just stumbled across this and couldn't resist.

the movie grows by 4.3% (25/23.97) a 120 min movie ends up being 125 mins, go to IMDB, and you think you have a director's cut with extra scenes

No, you'll get the correct length of the movie, as shown in the movie theater (and on IMDB).

you just have crappy encoding.

Nonsense. If you really want to try your blending method using CCE (don't know why you'd want to, though), just add ConvertFPS(29.97) to your script.

Plus you have to change the audio, and strecth it, that will change the pitch of the audio

That's right; you'll get rid of the awful PAL 4% speedup which pitches the audio about half a tone higher.

Solution 2: Drop the 25th frame, so that the you have the same duration of the video.

You're joking, right? That is in no way a serious solution.

So for "real" video standard conversion backups we need to use procoder.

No you don't. Blending frames is a very bad solution. You'll produce blended fields easily noticed on an interlaced or on a progressive display, along with that nasty "strobing" effect especially noticeable during pans. That destroys the video quality you're trying so hard to preserve. It may be a solution for interlaced sources, but for movies, no way.

Admittedly, backing up a complete DVD is quite difficult when converting from PAL to NTSC, and at the moment there is no automated solution. As influenza says above, you'll have to do it all manually (perhaps with some help from NuMenu4u). But for movie only backups it's deceptively simple. You resize (LanczosResize(720,480)), you slow it down (AssumeFPS(23.976)), you run Pulldown.exe on the .mpv, you stretch the audio, and you reauthor. I've done it several times with success. I've also done a few where a PAL master was used for the NTSC DVD. It's the same principle, except the AviSynth tools are different (RePAL or Restore24) followed by the resize, the framerate change and pulldown.

I have considered adding the option for format conversion however, you have to remember that our utilities are primarily for backup of DVD's you currently own and last I looked, it's not exactly an easy task to purchase a PAL dvd in NTSC land

I'm surprised at you, D3s7. It's as simple as going to (for example) Amazon.com UK and ordering them.

Edited later: I was thinking about it some more. Where I had originally mentioned ConvertFPS(23.976), I had meant to say ConvertFPS(29.97). It keeps the movie the same length, the original audio can be used, but adds frames in the form of blended fields.

[Zeul]

@manono
I am interested to know your preferred procedure for audio stretching? Presently in NuMenu4u I convert the ac3 into a 6ch wav with besweet and adjust the framerate. Then convert to ac3 again with softencode. Of course all can be done at command line.

[manono]

Hi Zeul-

I do it exactly the same way. I make the 6 Mono WAV files, at the same time using the BeSweet Preset to slow them to 23.976fps, and then into Soft Encode. I don't much like the AC3 encoder that's included with BeSweet. I know there are some other commercial AC3 encoders, but I've never used them, so I can't comment. Soft Encode is great.

[Zeul]

:)

[Zeul]

Going off topic a little but how do you resize the subs (assuming you keep them). Scenarist just crops them if you just drop them in, so at present I resize them with internal routines. I have found this to be generally successful, except where the overlay is words not images and directly covers the underlying video/still which also contains the same words. eg the word 'play' is etched into the video stream and the overlay, also containing the word 'play' is used for altering the highlight status. In this instance the overlay can be off by a couple of pixels.

[manono]

Sorry, but I can't help there. Since I don't know how to use the Big Three for format conversion DVDs, and have no idea how to use Scenarist on my own, I do it manually. I convert the PAL idx/sub files to 23.976fps using the Cutter utility included with VobSub, OCR the subs to SSA format, and import them into DVDLab or DVDAuthorGUI, which accept text based subs, and take it from there.

That's, of course, subs for the movie. As for subs for the Menus, I have no idea. Sorry, Zeul.

[D3s7]

Originally posted by manono
I'm surprised at you, D3s7. It's as simple as going to (for example) Amazon.com UK and ordering them.

I didn't say it was impossible :)

I just simply meant I couldn't go to the local store and buy a cheep one or go to the movie store and rent one...

[Yayita]

This discussion is getting spicy!
Good! :)

I respect Manono's corrections and opinions because they are coming from a knwledgeable source.

Would just like to add, that correcting the audio is not simple, and it is not done fast. All the channels must be converted to WAV and then adjusted, and then recoded.

That's right; you'll get rid of the awful PAL 4% speedup which pitches the audio about half a tone higher.

This makes sense only if the source was originally NTSC, then went to PAL land, and you want to recover it to NTSC. Not if the source is truly PAL.

Blending frames is a very bad solution. You'll produce blended fields easily noticed on an interlaced or on a progressive display, along with that nasty "strobing" effect especially noticeable during pans. That destroys the video quality you're trying so hard to preserve. It may be a solution for interlaced sources, but for movies, no way.

I can only say that you should try it. Maybe you become a believer like me. ;)

[manono]

Hi-

This makes sense only if the source was originally NTSC, then went to PAL land, and you want to recover it to NTSC. Not if the source is truly PAL.

If we're talking only about movies, then there is no true PAL source, is there? Aren't movies in the European movie theaters projected at 24fps also? Sure, the audio can be pitch corrected for PAL DVD. My understanding (perhaps wrong) is that it usually isn't pitch corrected. The few cases where I have been able to check the NTSC DVD against the PAL DVD, the audio for the PAL DVD hasn't been corrected.

[Yayita]

Manono,

You left me wondering about encoding without changing duration of the film. Check out the DVDs of "The Name of the Rose"; and I give this example because I have seen them both:

http://www.imdb.com/title/tt0091605/dvd

German PAL version 126 min.

NTSC and official duration 131 min.

Do the ratio. It seems that 24 fps are played at 25 fps and you end with the shorter movie in PAL land. And cross your finger that the company that releases the movie goes thru the hassle of correcting.

I think that further testing is required in this subject...

[Matthew]

Originally posted by Yayita
I think that further testing is required in this subject...

Not really, it is quite simple.
-Film stock=24 fps.
-NTSC movie DVD: slowed down to 23.976 and then pulldowned by dvd player to get 29.97.
-PAL movie DVD: sped up to 25 fps. Audio is sometimes (badly) pitch corrected. Most people can't tell the difference and don't care.

It's very seldom that PAL DVDs are not speed ups...it's the best solution available.

Anyway the point is for NTSC->PAL one should be looking to replicate the studios' 24 frame->PAL approach (i.e. speedup) and for PAL->NTSC one should be looking to undo it (i.e. slowdown).

@manono, re movie subs, resizing (as opposed to OCR) presents some quality issues, but I know from experience that the subs are watchable. I have my own crude automated technique for changing all the timecodes in the sons/ssts. The advantage is that OCR can be avoided.

[Yayita]

I agree with you Mathew.

Manono incorrectly states that the assumefps command does not change the duration of the film. From the avisynth manual:

The AssumeFPS filter changes the frame rate without changing the frame count (causing the video to play faster or slower).

Therefore it changes the duration of the film.

So I refer to further testing, to the results of both methods. Changing the speed in CCE vs. transcoding with procoder.

[Matthew]

The gist of my post was that a speed change was the most appropriate method because that either undoes or mimics what the professionals do when dealing with film->DVD. I don't think that's something you agree with =)

ConvertFPS changes the frame count and the length is kept constant. AssumeFPS keeps the frame count constant but changes the length. I don't believe manono said anything to contradict this :)

Also, unless I'm mistaken, something that hasn't been mentioned is that the bitrate available for each frame will be less when the framerate is "true" 29.97.

[Eyes`Only]

I've been interested in implementing this for a while now, so I'm following this discussion.

One thing I will comment on:

Sorry for the long post. And wait for my guide: "Real backups PAL<->NTSC for Big 3 users (main movie only)"
Anyone that knows me knows I won't support that, and I know Dest isn't a butchering-fan either, so I hope he doesn't either. Respect the art of the DVD.

[pipieye]

Originally posted by Zeul
Going off topic a little but how do you resize the subs (assuming you keep them). Scenarist just crops them if you just drop them in, so at present I resize them with internal routines. I have found this to be generally successful, except where the overlay is words not images and directly covers the underlying video/still which also contains the same words. eg the word 'play' is etched into the video stream and the overlay, also containing the word 'play' is used for altering the highlight status. In this instance the overlay can be off by a couple of pixels.

Hi Zeul,
When I do the menu PAL->NTSC manually, I use subrip to save the sub overlays "as is" in 720x576. Then I drop them into Maestro and it fits perfectly into the 720x480 frame. (ACDSee's size conversion with Lancoz also works.) I don't know if this info will help you in anyway. Can maestro be automated just like Scenarist?
I used to have problems where a moving menu turns into a static menu, you will notice the pixel shift up/down by a few pixels. This was solved with the maestro trick above. It has to do with the odd/even field versus the static bmp.
Cheers,
Pipi