Little Problem with NTSC to PAL converting

[s164381]

Good morning everyone!

I have a problem with NTSC to PAL converting. It's a US-DVD-Release NTSC (29.970 Pics/s also 29.970 Frames/s; Res.: 720x480) should be merged with italien and german audiotracks.

On TFT Computer-Screen (19"; 1024x768; 60 Hz) it looks well, just a view interlacing (combing) artifacts but not that much to use a deinterlace filter.

I converted to PAL using the combo Virtual Dub Mod 1.5.10.2 / XVid 1.1.3. (Yes I know where are better ways to do this, but I am not related to Stephen Hawking, so I have to go the easy way)

(My XVid settings: Advanced Simple@L5; Single Pass; Adaptive Quantisation; Quarter Pixel; Global Motion Compensation; B-VOPs; Display Aspect Ratio 16:9; Chroma Optimizer; VHQ for bframes; Chroma Motion; Maximum I-frame interval: 250)

I did this steps:

1. Frame Rate / Inverse telecine (3:2 pulldown removal) / Reconstruct from fields - adaptive (Result: 24.000 Frames/s)
2. Frame Rate / Source rate adjustment / Change to 25.000 frames per second (Result: 25.000)
3. Convert the AVI with ConvertXtoDVD, including automatic resize from 720x480 to 720x576.

The result looks pretty good (bettern than origin !!!) at the 19" TFT Computer Screen, i was astonished, that all interlace artifacts disappeared completely without using a deinterlace filter. Can not explain this.

But... on a 100 Hz TFT TV-Screen, where are more interlace artifacts than origin. Can not explain this either.

After that, i used the the VirtualDub inbuild Deinterlace Filter with "Blend fields together" mode, at least with many ugly block artifacts instead of interlace artifacts.

How can I get the Source to PAL without interlace artifacts on TV-Screen ? Can I use the Smart Deinterlace Filter v.2.8 ?
Shall i use such filter before pulldown removal ?

Thank you for help

[JonE]

i was astonished, that all interlace artifacts disappeared completely without using a deinterlace filter. Can not explain this.

If the original source used to create the DVD footage was film (I assume this is the case) then it was of course not interlaced. To convert to NTSC frame rates, it then got interlaced. Inverse telecine un-does this and gets back the original non-interlaced images.

How did you convert from 24 to 25 hz ? There are two ways of doing this
1) Keep the playback time the same - this conversion requires extra images to be inserted, and to minimise the impact of this you end up interlacing half the frames.
2) "lie" about the frame rate - tell it "assume you are 25Hz". The duration of the video will be reduced ~4% but no extra frames inserted so no interlacing introduced. Still got lovely non-interlaced footage.

In method 1, you don't have to do anything about the audio, it remains in sync. In method 2, you also have to reduce the audio duration to keep it in step. Most people won't notice the slight increase in audio pitch.

Now, lets assume method 1 -> frames now interlaced. If you resize the image (specifically the height) then if whatever you used to do the resizing didn't realise the source was interlaced then you will end up with a right ugly mess since each individual line is expanded by 576/480 i.e. now tries to occupy 1.2 lines.

So, make sure you use method (2) above.

TTFN,
Jon

[s164381]

@JonE: Thanks for your reply. The Doom9 Forum Server was not accessible yesterday. I did not understand everything you are telling about, sorry for this. Whats the meaning of "Hz" (Frames per second ?) and "playback time" (Frame Rate ?) ? Is it accurate that my problem is caused by the resizing from 480 to 576 ?

[manono]

Is it accurate that my problem is caused by the resizing from 480 to 576 ?
Possibly, if all or part of it was still interlaced.

This can't be easily or properly done just using VDub(Mod). The VDub IVTC, for example, is horrible when compared to an AviSynth IVTC. And you don't deinterlace movies. You should really use AviSynth to frameserve into your favorite MPEG-2 encoder. You're making a PAL DVD, aren't you? And doesn't your DVD player/TV set already play NTSC DVDs? Almost all of them do, you know.

Anyway, just so we can be sure of what you have and how it should be treated, please upload a 10 second sample - one with steady movement - somewhere for us to get and check out.

[s164381]

@manono: Thanks for your reply. I couldn't acces the forum for a view days, now I have noticed, that the Doom9 IP has changed. Should it be a vob-sample ? And I also have to find a place to send it to.

[Ghitulescu]

How about reencoding just the audio?
I still have to find the EU model that doesn't play NTSC (even as PAL60).
Normally, audio changes are less noticeable than a bad NTSC<->PAL video conversion.

You can adjust the length of the audio using TimeStretch without altering the pitch, the name of the function differs from software to software - SSRC or sox do a good job, they are more or less "transparent"

[manono]

We don't need audio so we don't need a VOB. Just the M2V will be plenty. Open a VOB in DGIndex and use the [ and ] buttons to isolate a small piece. Then File->Save Project and Demux Video. Upload the resulting M2V to MediaFire and provide a link.

[s164381]

@Ghitulescu: Yes I thought about converting the Audio-File to NTSC, but in my opinion it is the less-than-ideal solution.

@manono: I did, as you told me to do.

http://www.mediafire.com/file/dulmnm3ywtz/s164381 (Samples).rar

I detect another strange thing. DGIndex says, my PAL-Result is Progressive. G-Spot says, it contains interlaced material. (Screenshot included) After this I tried a second experiment. I transcoded the PAL-AVI/Xvid-Source (builded with VDub) lossless to DVD9 with ConvertXtoDVD while using the ConvertXtoDVD inbuild Deinterlace Mode. After this, G-Spot says it is progressive. Then I encoded with the Rebuilder/CCE Combo to DVD5, after this, G-Spot says, the material is interlaced.

[Alex-Kid]

Possibly, if all or part of it was still interlaced.
I think this happens too. Did you watch your video at full screen in your computer? If you did it and see interlacing too, manono is right.

If not, then I don't know. Maybe it's a bad setting (like pulldown on) in your TV.

[manono]

When I went to unRAR it, it says it's corrupt. Just upload the M2V. There's no need to RAR it up.

[Ghitulescu]

@Ghitulescu: Yes I thought about converting the Audio-File to NTSC, but in my opinion it is the less-than-ideal solution.
Could you elaborate a bit, why is less than ideal?

[s164381]

@manono: Sorry, here is the new one:

http://www.mediafire.com/?sharekey=db148aac189483d475a4fc82078ae6c80c10225e58af300877b784fef9ed9be3

@Ghitulescu: George Mallory -a famous mountaineer of the 1920s- is well known for his retort to the Question "Why do you want to climb Mt. Everest?" He answered: "Because it's there!" Its the same reason, why I want to convert NTSC to PAL. And PAL is not just "there", it is standart in Europe. ;)

[manono]

The NTSC one just needs an IVTC (not an VDub IVTC, but a proper AviSynth IVTC). It looks to me like the conversion to PAL was done properly.

However, you may not be able to match up your new PAL audios with the now PAL video. The PAL video was converted from 23.976fps to 25fps while your audio may have been (probably was) converted from 24fps to 25fps. This will mean the audio goes out of synch pretty quickly and will be over 7 seconds off by the end of a 2 hour movie. In addition, if the PAL version had different logos and such at the beginning, or different scenes, what you want to do may be a lost cause. You'll never know until you try, I guess.

[s164381]

@manono: Thank you very much. I try to get busy with AviSynth now and hope to become acquainted without studies at a university. Indeed I have worked 4 hours to get a proper video/audio join. You estimation was accurate, I extended the video in one scene -a car is approaching from far on a highway for 11 seconds- the car is approaching now for 18 seconds, let's call it the directors cut.:cool: At to times I have to prolong the audiotrack 1 second in a silent passage. The DGIndex is my first step towards AviSynth. Thanks and good-by.