PAL to NTSC conversion

Rickrender wrote on 5/20/2010, 1:52 PM
What is the best way to convert PAL to NTSC in Movie Studio 9 Platinum? I have MPEG2 footage shot in Switzerland at 720 x 576 x 32, 25fps, 1.0926 pixel aspect ratio, upper field first, and delivered to me via SDHC. I am trying different combinations of file and project properties, but at best am getting severe "ghosting" and audio sync problems.

Comments

david_f_knight wrote on 5/20/2010, 7:16 PM
I haven't done this before, but I'm offering an answer because I suspect not many others have either. If anyone else has experience with this, I defer to them. In the meantime....

I had once read about how film shot at a standard frame rate (i.e., 24 or 25 fps) is transferred to NTSC and PAL video. You could try a similar approach with your video. I believe the standard approach is to just transfer frames one-to-one. In other words, take your 25 fps PAL video and render it to 25 fps NTSC (but which will be shown at 24 fps, making your video run about 4% longer, and the pitch of all sound will be shifted something like a semitone lower, than the PAL version). The advantage is that that should eliminate all ghosting and the audio sync problems.

As you have currently rendered your video, I suspect that VMSP9 is interpolating frames to render your 25 fps source at 24 fps, and that is causing your severe ghosting and audio sync problems. The advantage is that your NTSC video should play the same length of time and have the same pitch as your PAL video.

Unfortunately, there is no ideal way to convert 25 fps material to 24 fps, i.e., without any artifacts of one sort or another. So, you have to choose which problem you are willing to live with. If you've watched foreign films from PAL format countries transferred to NTSC DVDs, chances are pretty good that you've watched a 25 fps movie transferred in the way I described to 24 fps. If you didn't find that objectionable (i.e., the 4% time lengthening and pitch change), then that's probably the way you will want to go. Most people don't notice the change, but the pitch shift can be an issue for some if your video is of music or if you will be cutting it with video shot at 24 fps and it has, say, the same person as in the 25 fps video, or if your video is of some time critical subject.

I don't have any specific render option settings to suggest, other than to render your video at 25 fps in NTSC format, and to turn off the resampling option. As for the difference in resolution, I believe that PAL has the same aspect ratio as NTSC even though a different resolution. I'm not sure how to deal with this problem, and in the absence of other advice I'd suggest some experimentation. It is a separate problem from the frame rate change, though, so you can work on it after you have figured out how to deal with that.

Good luck!
Rainer wrote on 5/21/2010, 7:20 PM
Set up your project to NTSC. Drop your clips on the timeline. Disable resample for all clips (this is what causes the ghosting). Use the NTSC DV template to render. That's basically it. You might find your audio at times is very slightly out of synch, but I doubt anyone else will notice. If it is a long way off, drop it back on the timeline, stretch or shrink it to fit your footage and render separately, the pitch willl be correct (with HD you get slight black bars top and bottom, this is inevitable since HD isn't exactly 16:9. You could resize to get rid of these, but they are mostly outside your viewing area). Don't worry about how frame rates and resolution is composed. Digital video is just a data stream which your software interprets and renders at any required frame rate (hard for people used to working with film to understand).