PAL to NTSC - frame rate question?

cal79 wrote on 9/23/2013, 5:29 AM
Hi Guy's

I've shot a live concert dvd in the UK, shot in PAL, it has a mix of 25p and 50i on the timeline. I have successfully made a PAL dvd, but I've now been ask to produce an NTSC version.

Regarding workflow:
Do I keep my project properties as they are to match the media, which is mostly PAL 50i and then choose an NTSC wide screen render template?

I notice the field order is the opposite to that of the my PAL template, should I change this or leave it be?

Do I output to 30p or 24p for an NTSC DVD? Will this cause any sync issues?



farss wrote on 9/23/2013, 5:43 AM
I'd make a 24p DVD.
It's quite easy to convert 25p to 24p, no sync issues, 50i can be de-interlaced to 25p pretty well these days as well. Multiple posts about all of this here.

musicvid10 wrote on 9/23/2013, 8:59 AM
cal79 wrote on 9/23/2013, 12:05 PM
OK, so on the DVD A 24p render template, frame rate is set at 23.976+ 2-3 pulldown as default, so do I need to change this?
johnmeyer wrote on 9/23/2013, 6:03 PM

There are several details about how to do the conversion that you can find in other posts. I've not done this for a long time, so those who have can correct me if this workflow is incorrect, but here goes.

1. Yes, you do want to use the render template you describe because 24p for playback in the USA is 23.976. A pulldown flag is added to tell the player to add fields to make the DVD play at 29.97 fps for a normal TV set. Modern DVD players and TV sets ignore this flag and actually play back the content at 23.976.

2. Because your original is 25 fps, if you simply render at 23.976, Vegas will decimate (delete) frames from your source. This is not what you want. Instead, what you want to do is to slow down your 25 fps material to 23.976. This is how most movies are shown on TV in PAL-land, and the slight slowdown is not noticed. To do this, right-click on your PAL clip(s) and reduce the playback rate. I believe that the correct number to enter is:

(1000/1001) * (24/25) = 0.959

Enter this in the Event playback rate for every event on the timeline. You should also disable resample. You can Copy/Paste Event Attributes if you need to apply this to multiple events.

3. Since the event is now playing more slowly, you need to do two more things. First, click on the video event and press "U" to ungroup it from the audio. Drag the right edge of the video event to the right until you see and "feel" the end of the clip (the diamond at the top of the event signals the end of the clip). Then, do the same for the audio event, except press and hold the Ctrl key prior to dragging the edge. This will stretch the audio to fit the video (Vegas only applies the "playback rate" setting to the video, so you have to handle the audio slowdown separately). Right-click on the audio and change the method to Elastique, and the quality to Pro. Finally, re-group the audio and video.

Now that you know the "magic" slowdown number, you can search this forum for "PAL" and "959" and come up with some additional posts that may fill in the blanks in my explanation, like this old post which contains advice from one of the ultimate Vegas gurus, "Spot:"

PAL 25P to NTSC 24P conversion - please help

cal79 wrote on 9/25/2013, 6:01 AM
Hi John,

Thanks for sharing your workflow with me, my project is very complexed so this could be a hugh task for me to do correctly.. i've got 7 video tracks, 1 stereo track and 6 audio layered tracks for 5.1

Is doing this ok for live concert dvd's ? the playback rate won't be noticed?

If I make these changes what would the result be on a multiregion NTSC Disc for playback be in PAL land? I know I should be making a PAL version, but I have been requested for an NTSC only version for all regions. If I had known this before I shot the event things might be different.
farss wrote on 9/25/2013, 7:42 AM
I'm not John but I'll do my best to help you out here.

1. AFAIK you cannot author a DVD that contains both PAL and NTSC.
2. No, the difference in playback rate will not be noticed, have you ever noticed the difference when watching a movie in PAL land? You're see it 4% faster than it's seen in NTSC land and in the cinema.

What I would suggest you do is this.

1. Make certain you edit project is set to 50i.
2. Nest it into a new project. Using JM's method or similar retime it to 23.976fps.
3. Apply the YADIF plugin using the script that comes with it.
4. Render out as required.

What'll hopefully happen is Vegas will covert your 25p footage to 50i in the child project but both fields will be identical, the 50i will stay as is. All that 50i will then be de-interlaced by YADIF in the parent project. I strongly suspect the 25p material will just have the two fields merged back into frames and the 50i content will be actually de-interlaced.

Kimberly wrote on 9/25/2013, 8:20 AM

I'm not a Guru, but here's a workflow that I follow when I need to convert from NTSC 24p (23.97) to PAL. Maybe something in the reverse will help you? However I wonder if you would lose sync in audio with video. I don't have that problem in my projects because I mute the native audio and play music.

1. Render the audio for your project in the customary way. I'm not an audio person so I cannot say whether the audio knows it's PAL or NTSC. But I think it just knows it's audio.

2. Resize (if going from HD to SD) and change the frame rate on your video in VirtualDub. I use AviSynth to frameserve to VirtualDub so that I don't have to create intermediate files.

3. Bring the AVI file back into Vegas with the appropriate DVD-A template and your audio from step one.

4. Stretch/shrink the audio to match your AVI file. Or stretch/shrink your AVI file to match the audio.

The above workflow is courtesy of vxtrocketeer and others. I left out a few details but that's the gist.

Good luck!

cal79 wrote on 9/25/2013, 9:07 AM
Thanks everyone for sharing your method,

Bob, could I also use the Boris Continuum Complete deinterlace plugin? i've got that installed.

When nesting a project how would that effect my 5.1 audio tracks? would this remain the same? I have to render out a stereo track and a 5.1 track for dvd selection.

Would I be safer to copy and paste audio from the main project, then stretch it?

markymarkNY wrote on 9/25/2013, 10:22 AM
I would render all the audio clips in a particular track together into one large file first. Then when you add it back to a reduced playback rate timeline you can stretch the entire audio track at once.

Something like Vegasaur may have some built in scripts that might automate some of the tedious things. For example, you can disable resample to all your clips in one shot instead of copy/ paste event attributes. Vegasaur has a 30-day fully functional trial so you can take advantage of that.
farss wrote on 9/25/2013, 2:29 PM
[I]"Bob, could I also use the Boris Continuum Complete deinterlace plugin? i've got that installed."[/I]

Cannot think of a reason why not.

[I]" When nesting a project how would that effect my 5.1 audio tracks? would this remain the same?"[/I]

Never tried a 5.1 output buss with nesting.

[I]"Would I be safer to copy and paste audio from the main project, then stretch it?"[/I]

That should work just fine.
Always check that Vegas is using Elastique for the pitch shifting.