PAL to NTSC conversion HELP

[Sugar]

I want to convert an avi PAL file from my sony camcorder, captured and edited in Premiere 6.5 and put it onto a NTSC disk (yes, I need it in NTSC).

I am converting the avi in NTSC with avisynth and compressing it with TMPGEnc. The result, although good for still plans, show some flickering lines in pans.

The script I use is as follows:

LoadPlugIn("SmoothDeinterlacer.dll")
DirectShowSource("d:\file.avi") #AviSource or OpenDMLSource won'twork
SmoothDeinterlace(tff=false,doublerate=true)
LancosResize(720,480)
ConvertFPS(59.94)
SeparateFields()
SelectEvery(4,0,3)
Weave()
ConvertToRGB()

I probably do not need that last command because I read that Premiere works in RGB only.

Can somebody HELP me to get a clean picture ?
Is it necessary to doublerate in Smoothdeinterlace ? Is it not possible not to doublerate, change the frame rate to 29.97 and re Weave without sperating the fileds to select the 1st and the 4th one?

Alternatively, is it possible to compress my PAL avi into a PAL m2v file, open it with DirectShowSource and use the script above (changing tff to true and Selectevery to 4,1,2) to get a m2v NTSC compliant file ?

If somebody has gone through that before please help me. The conversion/compression/DVD burning process is very time consuming and nights are only 8 hours long.....

[DivXExpert]

Don't Deinterlace. DVD (MPEG-2) Supports interlaced picture, Deinterlacing would be bad.
Since its from a cam, its pure interlace, so you can't slow it down and then telecine, instead just speed it up. So do this script :

DirectShowSource("D:\file.avi")
AssumeFPS("29.97")
LanczosResize(720,480)


You don't want to delete frames, that is where alot of people go wronge. Deleting frames results in jerky motion.

You now have to speed up the audio. I use BeSweet to do this.
You could also use SoundForge to speed up the audio, so that it doesn't change pitch.

Encode it as MPEG-2 Interlaced.

[DivXExpert]

This does change the playing time, but it is the correct method of conversion.

[DivXExpert]

Also the lines in pans. Thats called interlacing. It won't show up on the TV. Because the TV is interlaced.

[malducci]

Since your deinterlacing your video, then why don't you use AssumeFPS(23.976) in avisynth, edit your hearts content with premiere, encode to mpeg2, and then use pulldown.exe to flag the video to 29.97. Almost all conversions from PAL to NTSC: is to slow down the video/audio by 4%(keeping the pitch) and use 2:3 pulldown.

I'm not sure if you can have a 23.976 interlaced video or not. I have never tried it. Still, FPS out of the way - there is the matter of veritcal resolution. Resizing interlaced video is a bad idea. I would do a smart deinterlace, slow down the video to 23.976, and then resize the video.

Most cases you would want to keep the video interlaced if the source is a true interlaced video. But since your doing a frame rate conversion and more importantly a resize on the vertical resolution, you might want to actually deinterlace the video.

I don't know what your budget is, but you should check out RE:Vision Effects - Fieldkits. I've used it for After Effects, but I'm pretty sure that they have a Premiere plug in. This is an intelligent deinterlacer with a lot of options. Using Fieldkits and Twixter together gives even more deinterlacing options - especially if your trying to get that temporal film look.

PS: Don't speed up the video to 29.97fps - thats a 20% increase in speed. Slow is down to 23.976 which is only a 4% decrease in speed from the original.

[Sugar]

DivXExpert> Why do you need to change the audio ? I thought that changing the FPS was adjusting the number of frames per second but not the overall playtime. Besides, changing the fps for audio, changes the replay time or doesn't it ?
And yes, I guess I see some interlacing on my TV when I play the DVD.

Malducci> Will my player play at 23.976 fps. Can you elaborate on pulldown.exe. I am not familiar with this approach. Can I do that with avisynth ? Do I convert my avi file and then compress it my TMPGEnc or do I convert the mpg file ?

Hey guys, thanks for your help.

[DivXExpert]

Changing the Frames Per Second is exactly that. If you film a movie at 25fps, then you physically project it with a projector at 29.97fps, the projector does not start desintigrating frames of film, it simply plays them faster, thus changing the fps. You want to do the same thing. You HAVE to change the play time to do it correctly. Deleting frames, or duplicating them is not correct, it results in very jerky motion. Trust me. The quality of your movie is what is important, not the playing time.

[Sugar]

Ok, now I think I understand. So the script you sent changes the play time ?
Can you explain how I change the audio with Besweet ? Last time I tried, it changed the audio replay significantly. I may have done something wrong.

[DivXExpert]

I didn't think about the interlaced video being resized.
So do this.

DirectShowSource("D:\file.avi")
SeparateFields()
LanczosResize(360,480)
Weave()
AssumeFPS(29.97)

[DivXExpert]

If the speed up is too fast (I think it might be). then do this.

DirectShowSource("D:\file.avi")
SeparateFields()
SelectEven()
LanczosResize(720,480)
AssumeFPS(23.976)

Then encode as progressive MPEG-2 23.976fps
ES Video Only

Download pulldown.exe, just drag the .m2v into it.
Mux the New .m2v that pulldown made, and mux it with the audio.

Slow down the audio with SoundForge, because it will do a better job than Besweet. SoundForge doesn't change the pitch, Besweet will make it sound a little boomy.

[Sugar]

Oops, sorry DivXExpert but ChangeFPS does just what you said we do not want to happen. When changing from 25fps to 29.97 fps, it creates new frames.

And in that case, play time is the same and I do not need to change my audio file.

The file processed form my initial script plays in sync with the audi from my PAL footage.

[DivXExpert]

Then do not use ChangeFPS. Use AssumeFPS.
ChangeFPS is good if you are doing a framerate convertion that is unreasonable, i.e. 29.97 pure interlace to 23.976. But also creates a slight blur.
When you could just slow it down, and retain all the sharpness. It requires more work (audio slow down) but is well worth it. Save the ChangeFPS command for when you really need it.

[MrKGB]

instead of resampling audio with besweet one can do the same in the avisynth script:

#############################
#not sure which one is right, try both:
#ResampleAudio(44100 * 23.976/25)
#or
#ResampleAudio(44100 * 25/23.976)

AssumeSampleRate(44100)
#############################
the idea is that we first make sound running slower (or faster), and then change its frequency back to normal, effectively we change the length of the sound track.

The whole job for video and audio will be done in avisynth.

Please note that at least 2.07 avisynth must be used.
I never used this method for pal/ntsc conversion, but i use if for fixing sync issues (this is my own invention ):

#############################
ResampleAudio(44100-6)
AssumeSampleRate(44100)
#############################

and it works very well, no hassles with muxing/demuxing, running through besweet and i couldn't see any degradation in sound quality.

[malducci]

That's pretty interesting MrKGB. I remember reading somewhere that AssumeFPS was supposed to slowdown the audio and keep the pitch, but I never got it to work for audio.

#not sure which one is right, try both:
#ResampleAudio(44100 * 23.976/25)
#or
#ResampleAudio(44100 * 25/23.976)

I wonder if it will keep the pitch? I used cooledit to stretch audio while presurving the pitch.

[MrKGB]

i also used to use cooledit for stretching or shrinking audio, but it is very long story.
with avisynth i am able to resample very easily.
for example the script below will resample audio to compensate for slight audio out of sync:

ResampleAudio(48000-7)
AssumeSampleRate(48000)