Converting PAL to NTSC from Mpeg source

[markrb]

I have been reading the thread "how to covert PAL to NTSC" found here http://rilanparty.com/vbb/showthread.php?s=&threadid=11426 and have some questions.
I have a PAL mpg video. It is Mpeg1 352 x 288 25fps. I wish to attempt to convert it to a NTSC VCD compliant video or as close as I can because the audio is only 128 bit.
I understand from the previous thread that I should convert the video to a 23.976 fps avi in Virtual Dub with audio unchecked.
I cannot seem to use direct stream copy with this video. I get an error about the formats are not compatable. I select full processing mode and the error goes away. My big issue is that Virtual Dub wants to create a 31gb avi from a 750mb mpeg file. I have only about 27gb's free for this. It is suggested before I start the conversion that I use compression. Should I? If so which one. The ones that give me no format restrictions in Virtual Dub are Microsoft Video 1, Intel IYUV codec, Intel .263 video driver, Cinepak Codec by Radius. Every other compressor gives me some sort of restriction with the video.

Ok onto the audio. What should I use to make a wav file out of the mpg video? Can I treat it just like a DVD and use the audio instructions in the DVD rip guides? What can I use to stretch the audio by the stated rate in the previous thread?

Lastly it is possible that this video suffers from macrovision, but I am not sure. Is there a stand alone program to remove it? I have looked all over Doom9, but can't find anything.

Thanks,
Mark

[ppera2]

When source is mpg, it's not good idea to use VDub.

Here is methode: load mpg into TMPGenc, select only video.
At settings, advanced check 'Do not framerate conversion' .
At video set framerate to 23.976 .
Save project (not mpeg file ! So spare time and unnecessary conversion which degrades quality).

Now load that tpr project to TMPgenc and deselect 'Do not framerate conversion' and select (check) 3:2 pulldown. You will see that you have now 29.97 fps. Just set rest to get standard VCD...

It was for video. Before it must extract audio somehow and perform timestretch for factor 25/23.976 . This must be then feed to TMPGEnc as separated audio source by second stage.

Other methode would be to use VDub as frameserver, but described is simpler. Actually we use here TMPGenc as frameserver to himself too.

[markrb]

I have tried every method I can think of with the mpg file including your method above. When the encoding is done every few seconds it seems to be interlaced. It is showing black bars across the screen. I have tried to use the mpeg file and check de-interlace, but the video is degraded by quit a bit using odd-even. I looked at others, but they all seem to degrade the video.
The original plays fine on my PC, but the goal is to play it on my DVD player with the best possible video.

Any thoughts?

Mark

[Infinite_stupidity]

ppera2, why do you make it so confusing??? The way you described it is in reallity just reencoding the video, so why do you need to do all that extra stuff just to do that? The way I've always done is to just load the pal mpg file, select video only, and set all the correct settings for ntsc vcd (352x240, 29.97, 4:3 525 line ntsc, etc...), and hit start. Then demux the audio from the pal mpg, adn mux the ntsc video and the pal audio. This way gives the same quality as yours (they are both reencoding it) without having to do all that framerate conversion crap and timestretching the audio. So why oh why do you make it so complicated?

[ppera2]

markrb: it is normal that you have interlace when perform 3:2 pulldown. When playing on TV it will be OK.

Infinite: Reason for complicate method is to get smooth movement.
When you make simple framerate conversion as described encoder will get 29.97 from 25 by repeating some frames. It will cause noticable movement speed changes.
And it is not just reencoding video, it is correct method of framerate conversion. Look at FAQ about 3:2 pulldown.

Btw. PAL DVD's are made by speeding up FILM, NTSC is made by 3:2 pulldown, what is better methode than framerepeat. So PAL is timestretched, and audio must be shorted for ~4%. When convert from PAL to NTSC we need to restore back original audio duration.

[markrb]

I finally got an encode done. TMPG kept giving me errors.
I made a test version of the mpg by using an mpg cutting program so I can do tests without waiting all day.
When I finished I burned it on a CD and played it in my DVD player.
The video is only in the top left hand corner of the TV. The whole thing is there and the aspect is right. I didn't see any interlace bars, but the video was very small.
I am re-encoding the video now using VGA 1:1 as the setting to see if that will work.
You are right about the audio it's way out of sync. I only encoded the audio as a test to see how bad it actually is.

Mark

[markrb]

First off thanks for trying.
I have decided to give up.
I finally got several encodes to work on my DVD player, but the video quality is aweful. I tried several different settings with no luck.
I tried to burn the file as is with Nero again and it plays in my DVD player. The video quality is far better then all the frame rate and size converted videos I tried. I was hoping that by making the video fit the NTSC VCD spec it would come out better, but it's just not working well.
Maybe my DVD player has the ability to convert internally or maybe it just doesn't matter.

Thanks,
Mark

[ppera2]

You need some practice with TMPGenc. Resizing is pretty confusing for example.
CD burners have good conversion tools. I get good results with WinOnCD. However it is made with frame drop or insert. Bad movement is not too showy usual.

[Clydesdale]

I started the earlier thread referenced by Markrb but am still quite confused by this whole process. It seems there are a lot of opinions out there :D Can someone answer this: is reformatting mandatory in order for a 25 fps divx or mpeg to play properly on an ntsc tv? I have now had 2 such divx's and the usual conversion to svcd produces only ok video and out-of-sync audio, so I'm guessing reformatting IS mandatory.

Ppera I didn't understand your audio instructions above. Doesn't audio have to be shrunk to keep it in sync with video which is being changed from 25 to 23.976 fps? What is best method to do this?

[ppera2]

You must enlarge audio by factor 25/23.976 it is 104.2709 % .
Extract wav (uncompressed) with VDub, or if source is Mpeg2 with DVD2AVI. Then you can do it with some good audio (wav) editor like Wavelab, SoundForge etc...

[Clydesdale]

But if we're shrinking video from 25 to 23.976, it seems to me that expanding audio in the opposite direction will make it further out of sync. Arithmetically it makes no sense.

[ppera2]

When you decrease framerate (speed) it will play longer.....

[Clydesdale]

I tried this time-stretch with Soundforge but audio was still out of sync. I guess I have to keep adjusting the stretch and testing with small clips.