Perfect NTSC to Pal conversion?

[FirstBorg]

Hi
I encoded an NTSC avi File into pal.
When I watched it as NTSC, my DVD player does the conversion internaly, but that leads to skipping some frames, to have the 25 fps.
I suppose thats the fastest method to do realtime conversions.
Now I encoded it again, but this time, directly as PAL.
Now, I have less skipping, but its still not smooth.
It has regular skip every one second or so.

I choose 25 as fps, 720x576 as resolution (for the dvd) and chose PAL as video format. And I chose as max frames for GOP 15.

Is there another option which I may have not checked, to increase smoothness?

And one question... what is the Profile & Level option?
Does it affect playback on standalone players?
thx

[E-Male]

there are some avisynth scripts for pal<->ntsc

1st question is if you can live with a speed change of 4%

[FirstBorg]

I can.
I did not notice a change in audio pitch, or desynchronisation.
Only thing that bothers me are the regular frame skips.

[E-Male]

so if it is 24fps (or telecined) material just do the speed up and resolution change in avisynth (besweet for the audio)

[FirstBorg]

Hi again.
Im still having this skip... looks like every second one frame is skipped...

@E-Male
The source is 23.76 NTSC, and I konvert it to 25 fps.

[E-Male]

i see no reason AssumeFPS would cause problems like this

[FirstBorg]

I think that just the way tmpeg does the conversion... could it be right?

[Kika]

looks like every second one frame is skipped...

This happens if TMPGEnc is doing the Framerate-Coversion. But there's no need to do that. Use a AVISynth-Script with AssumeFPS(25) or activate "Do not frame rate conversion" in Settings -> Advanced (TMPGEnc). Both ways will work propperly, but you have to SpeedUp die Audiopart separatly.

[FirstBorg]

Yes, but I want to avoid the speed up :)

[Kika]

But why? That's the Standard-Technique for storing Film-Source on PAL-DVD.
If you want to avoid the Frequency-Change as a result of the speedup, use a good Tool like WaveLab which is able to do the speedup without pitching the sound.

[keithmac]

I use VirtualDub to speed the Source framerate up to 25fps (film ends up slightly shorter) and besweet/softencode to alter the audio.

Tmpgenc duplicates a frame at the end of every 24 to get the 25fps, it looks awful!

As said above, this is how the studios do it and I don`t have any problems watching the pal versions.

[FirstBorg]

Ok, I will try it, and then compare it to my pak version :)

[FirstBorg]

Did it... works great...
I converted the audio using the 23.976 --> 25.000 preset in BeSweet.
I notice a slight increase in the pitch... how can I decrease it again?

[Kika]

I converted the audio using the 23.976 --> 25.000 preset in BeSweet.
I notice a slight increase in the pitch... how can I decrease it again?

By not using BeSweet. I'm doing this with WaveLabs Time correction. Set the Speed to 95.904 and choose High Quality. That's all. The Audio-Part will have toe correct lenght without any Pitching (sounds exactly like the original)

[Warrych]

The easiest way to convert NTSC to PAL or vice versa is using VirtualDub as a frame server.

Due to the basic editing featurs of VirtualDub it is also possible to cut the source. Link:

http://sourceforge.net/projects/virtualdubmod

[FirstBorg]

I just tried the demo of wavelab 5, and it cannot open ac3 files.... my audiosource is ac3, though, just 2 ch.

[Warrych]

Well, in this case you should separate video and sound. The AC3-sound could be multiplexed later unchanged with the reencoded movie using the MPEG-tools within TMPGEnc.

[FirstBorg]

Yes, but after, demuxing, it has the ac3 filetype... I could ocnvert it to wave with besweet, without chaning the speed.



@Wavelab....
Somehow, I just cannot klick on apply in the time correction dialogue...

[Warrych]

Originally posted by FirstBorg
Yes, but after, demuxing, it has the ac3 filetype...Well, yes. So, what? Simply multiplex it with the new encoded MPEG-Stream.

[FirstBorg]

No, because I have to convert this ac3 file. But the conversionprogram, cannot read ac3... got it? :)

[Warrych]

But why?

I thought, the goal is to make a new DVD to play it in your DVD-player. Every DVD-player accepts AC3...

[FirstBorg]

No, the goal was to make a Pal DVD out of a ntsc source. And for that, I need to speed up the audio, but because the software cant read ac3, I have to convert it to wav.

[keithmac]

I think Kika uses wavelab on the outputted files from besweet? you can use besweet with no ota switch and get 6 waves of the original lenght/pitch, use wavelabe for time correction and then re-encode to ac3.

To be honest I haven`t really noticed the difference in pitch myself.

[Warrych]

Originally posted by FirstBorg
No, the goal was to make a Pal DVD out of a ntsc source. And for that, I need to speed up the audio, but because the software cant read ac3, I have to convert it to wav.
No, you don't.

One of the advantages of using a frame server is the fact, that doing so will not change the time line of the original file. So you don't have to change the audio speed.

Trust me on this, I've done it over a hundred times :D

Ok, in case the original file has a non DVD standard audio part, you have to make it conforming. But AC3 works fine.

[keithmac]

You can use a frameserver to stretch 24fps to 25 but most people just speed the video up by 1 fsp, in this case you will need to adjust the ac3 stream.

Personall I always speed it up, looks better imho.

[FirstBorg]

@Warrych

You say, that If I speed up the video, which changes the lentgh, I do not have to change the audio?

You know, this will lead to audio/video desynch?

[Warrych]

@keithmac: This will work only, if the source is converted to NTSC using telecine. (.VOB or ripped DVD i.E.) In this case you could do an inverse telecine to reconvert it to 24 fps. If the source is progressive in nature (most downloaded files) this will not be successful.

Better quality? Well, theoretically...

Originally posted by FirstBorg
@Warrych

You say, that If I speed up the video, which changes the lentgh, I do not have to change the audio?

You know, this will lead to audio/video desynch?
It is the other way round. If you speed up the video, the audio has to be changed too. Here is the advantage of using a frame server. There is no need to speed up the audio afterwards.

[FirstBorg]

how comes that? How can a frameserver convert a fixed number of frames, into another fps, without changing the lentgh of the video part, and therefore without the need of changing the audio?

[SeeMoreDigital]

There's a tool called ReStream that will allow you speed-up or slow-down Mpeg2 elementary (.m2v and .mpv) video streams... I've been looking for a similar tool for Mpeg4 streams... sadly without success :(

What tools/apps are some of you guys using to mux your Mpeg2 video and their associated audio streams together with, these days?


Cheers

[keithmac]

If it`s AC3 or any other DVD compliant audio I use TMPGEnc DVD Author

[SeeMoreDigital]

Are there no free tools?

[Warrych]

I use the MPEG Tools within TEMPGEnc. Works best for me.