Convert PAL to NTSC?

tocsese wrote on 11/22/2003, 11:38 AM

Hello All,
If I open an MPEG 2 PAL in Vegas, is it as simple as just rerendering it to convert it to MPEG 2 NTSC? Do I have to worry about resetting the resolution and framerate manually, or does Vegas do it automatically?

Thanks from a Newbie

Comments

farss wrote on 11/22/2003, 3:02 PM

That's all you need to do.

You might want to want to try a small section to see what impact teh de-interlace method setting makes. I haven't been able to notice any but...

BTW it will take a long time to render. VV will have to gofrom PAL mpeg to PAL DV to NTSC mpeg. If you want to do some further tweaking it might be better to first render the PAL mpeg to PAL DV, make any changes here and then encode to NTSC mpeg.

Chienworks wrote on 11/22/2003, 3:31 PM

Slight correction: there isn't any DV step inbetween. Vegas will decompress each frame and then recompress to the other format. You could think of the intermediate frames as being uncompressed AVI. If it actually converted to a DV format inbetween then the video would also experience a 4:1:1 color compression, but this doesn't happen when transcoding MPEG directly to MPEG.

Rendering to a DV file inbetween will require two renders, take a little longer, and suffer more quality loss. Rather than do this step, try a short sample direct to MPEG and evaluate the results. Tweak based on this short section, then render the whole thing direct to MPEG in one shot.

farss wrote on 11/22/2003, 4:37 PM

Good point!

Given then that VV needs to create a series of intermedieate frames to handle mpeg that would explain why it takes so long to convert one mpeg format to another. I'd imagine having a fair bit of RAM would help also, it must need to hold around six to ten frames of uncompressed AVI.

Given the quality of the VV DV Codec how serious is the quality hit likely to be do you think. Guess that's a fairly subjective evaluation anyway.

Chienworks wrote on 11/22/2003, 7:02 PM

The SONY DV codec is very good, however the colorspace is 4:1:1. MPEG is usually 4:4:4, so if you don't have to go through DV inbetween you'll keep the colors more accurate.

tocsese wrote on 11/22/2003, 11:54 PM

Thank you both for the advice and knowledge, it is appreciated!

netkoala wrote on 11/23/2003, 2:15 AM

I'm no expert but you could try converting either NTSC or PAL to 24p 2-3-3-2 pulldown.
Means removing interlacing and good for DVD burns and highly compressed renders.

Least that is my reading.
Comments ????? drawbacks ????

jamcas wrote on 11/23/2003, 3:02 AM

is your mpeg going to end up on DVD and do you use DVD architect ?

I have the need to create PAL and NTSC DVDs.

I gather all my source files that have been edited and then create the DVD with DVDA and let DVD take care of the renering to produce NTSC or PAL DVDs (from the project proerties).

Is there any dis advantage in doing it this way ?

regards
Jc

farss wrote on 11/23/2003, 3:42 AM

Not at all, that's th eway I've done it to date and had no complaints so far.

I have checked it on a broadcast monitor and well it wouldn't accept the output from the DVD player until we switcehd it to NTSC so it looks like it must have worked.

One downside to a NTSC DVD, as far as I can work out you fit less video on it due to the higher frame rate. Going to 24p is an interesting idea but I don't really know how that would work. The again maybe it would. Covert to NTSC and then do the reverse telecine thing to convert to 24p. It'd have to look horrid at real 24p playback but then if the player converts it back to 60i all should be well, I might try it one day, could save a lot of space on the DVD.