1080 24p to SD 29.97 Interlaced Conversion

1080 24p to SD 29.97 Interlaced Conversion
by Randy Rubin on Sep 21, 2016 at 3:05:18 pm

Hi All,

I'm prepping a video for broadcast and am trying to determine the best way to do the conversion. I've outlined what I've done via After Effects but I'm not sure it is to spec and I'm curious if there is a way to do this via Premiere or Media Encoder.

Delivery Requirements:
1. Apple ProRes 422(HQ) NTSC 48kHz
2. 29.97 fps
3. 9:10 (D1 Pixels)
4. 720x486 or 720x480
5. Bottom/Lower field first

After Effects Steps:
1. Output 1080 24p ProRes HQ 422 Master
2. Import to After Effects and create a composition
3. Set comp to NTSC D1 (720x486) (not widescreen)
4. Fit to Comp Width
5. Add comp to Render Queue
6. Render Settings -> DV Settings and set 3:2 Pulldown pop-up menu to WSSWW, Lower Field first
7. Set Compression type to Apple ProRes HQ 422 etc.
8. Output

Thanks!

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Tom Laughlin on Sep 21, 2016 at 3:23:43 pm

I'm not an expert on this, but can offer a few suggestions:

1. Drag your uncompressed 24p master into MPEG StreamClip, convert to 29.97, and see how it plays.
2. Convert your 24p footage to 29.97, and save to a separate folder, duplicate your sequence, and then reconnect your raw media folder to the 29.97 folder, render, export, and see how it plays.
3. Broadcasters are getting more and more mixed video every day, so rather than converting from 24 to 29, see if they'll take just 24p. Or, what I've done in the past is, if they want 29.97, let their own techs fight this issue out. Send them the 24p master, let them convert it, or, beat themselves up over it, but in some cases, they may just take it in 24p.
4. Export your 24p sequence directly out of Premiere, at 29.97, see how it plays.
5. There are more expensive routes others have taken, involving taking it to a post production conversions house, where they do a more expensive and it's like a true frame-rate algorithm conversion or something that takes time and money. I heard about this problem on "Meet the Mormons" documentary, when they were using mixed footage and FCP7, and they ultimately had to do a "hardware frame-rate conversion", rather than a software-driven frame-rate conversion".

Sorry if none of this helps,

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah
http://www.digitalchophouse.com

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Dave LaRonde on Sep 21, 2016 at 3:33:48 pm

Your description looks good; it should work fine. Just one question: scaling to comp width results in letterboxed video. Is that part of your delivery spec?

Since you didn't mention it, I have to ask this, too: do you really mean 23.976 fps when you write 24P?

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Randy Rubin on Sep 21, 2016 at 3:35:29 pm

Hi Dave,

Yes, I mean 23.976 Progressive. Should I Scale to Fit Comp?

Thanks!
Randy

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Dave LaRonde on Sep 21, 2016 at 3:46:58 pm

I don't think so. You're working with 16x9 HD and delivering 4x3 SD. It's a question for the client.

Does the client expect letterboxing (your current scaling strategy), images that fill a 4x3 screen, or the complete 16x9 image, which means the images will be squished horizontally?

I'll guess you should fill the 4x3 screen. It's a GUESS, not a statement of fact.

If that's so, you may have to animate the video's horizontal position to keep the significant portions of the 16x9 picture in the 4x3 frame. It's a process called Pan & Scan, and it's not automatic; computers aren't psychic, and they don't know what you think is the significant part of the picture.

In any case, you should contact the client to learn what's expected.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Randy Rubin on Sep 21, 2016 at 3:49:39 pm

Thanks that's helpful. I ended up delivering and receiving approval on the Letterbox format as the client preferred not to crop.

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Dave LaRonde on Sep 21, 2016 at 4:07:18 pm

Cool! You're all set.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: 1080 24p to SD 29.97 Interlaced Conversion
by Tero Ahlfors on Sep 21, 2016 at 4:02:06 pm

AME should do the pulldown automagically. So put your master file into AME and export it with your specs. Note that you need a reference monitor that can show interlaced footage properly to check it. It might look kinda weird with a computer monitor.