Mixed frame rates

[Shane Ross]

Well, you can mix 29.97 and 59.94 easily enough. They divide evenly…one is 30fps, the other is 60fps. It’s the 23.98 that becomes the issue. It is better to convert 23.98 to 29.97 than 29.97 to 23.98…because you get better results doing so. In doing this, you will need to have an interlaced timeline, and convert the 23.98 to interlaced 30fps…that’s how it spreads out the frames, but converting them to fields. So use 1280×1080 as the default sequence setting.

Here’s how you do it:

23.98 to 29.97 via Compressor:

1. Drop clips you want to convert into Compressor

2. In Compressor, select your video then right click and choose NEW TARGET WITH SETTING > APPLE > FORMATS > QUICKTIME > APPLE PRORES 422 (HQ). Or pick whatever codec you like to work with.

3. Click on that newly created compression setting to open it in the Inspector window. Click the Encoder tab. Click the Video: (Settings…) button. Make the frame rate 29.97. Check the interlaced box. Set it’s drop down menu to Bottom field first. Click OK.

4. Click the Frame Controls tab. Set Frame Controls to On. Set Output Fields to Bottom first. Leave Deinterlace on Fast. Leave Adaptive Details checked. Leave Rate Conversion set to Fast. Leave the Set Duration to: on 100% and make sure it’s radio button is selected and NOT the “so source frames play at 29.97 fps” button.

5. Make changes to the Filters or Geometry sections as needed. Those settings listed above are the ones critical to getting the proper 3:2 pulldown added.

6. Submit the compression, then bring the resulting video back into Final Cut Pro. Place it in a 29.97 timeline and make sure you watch it on an NTSC monitor to verify that it looks good. If you step through it frame-by-frame you should see the familiar pattern of 2 split/interlaced frames followed by 3 whole frames. This is a very important step. I tried many solutions that looked OK playing back on the computer monitor, but looked terrible on the NTSC monitor.

Yes, this will make the clips no longer reference the originals. But you are at full quality, so you might not need to reference them.

Shane
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[Jordan Shane]

Thanks so much for your quick and detailed response, Shane! Just a quick follow up question if you don’t mind- is there no way to do a frame rate conversion and still be able to reference the originals?

Thanks again, I really appreciate it!

[Shane Ross]

[Jordan Shane] ” is there no way to do a frame rate conversion and still be able to reference the originals?”

Nope. Once you convert the frame rate, FCP cannot relink to the originals. Frame rate is a BIG deal.

Shane
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[Jordan Shane]

Much appreciated. Thanks!

[Bret Williams]

There’s another option I’ve used, but Shane might know a good reason not to. He knows his stuff in this arena for sure. But I’ve edited in a 720p60 timeline in this circumstance. Usually it’s not an option in my book because of the lack of quality compared to 1080, but since much of your footage is already 720p, this might actually be acceptable to you. In a 720p60 timeline FCP actually spreads out the 24 frames correctly over the 60 frames. And of course your 60p remains the same and your 30p just doubles the frames. You’re left with a 720p60 master than can be broadcast as is, or interlaced to 1080i or downscaled and interlaced to 480i for DVD.

This has always been a shortcoming of FCP. Other editing apps, FCP X included, can drop 24p into an interlaced timeline and they simply add the appropriate pulldown.

[Shane Ross]

Ah, yes. That’s a good option too. A 720p60 sequence mixes 24p well.

Shane
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[Jordan Shane]

Thanks for the alternative, Bret!

[Joseph Owens]

[Shane Ross] ” A 720p60 sequence mixes 24p well.”

Because the 60P is mimicking the behaviour of an interlaced 60-field 29.97 timeline. Be aware that true 720P60 should have an AP Advanced Pulldown pattern of 2:3:3:2, which makes it easier to reverse telecine — one caveat is that the Panasonic pulldown removal tool will only work with DVCProHD in that format.

The reason why should be obvious as it is much more difficult to reverse telecine 2:3:2:3 cadence than throwing away the redundant “middle” frame in an AP codec.

I wold not choose DVCProHD as an editing format — although it is fairly compact, that is one of the reasons it is also a fairly lossy codec.

jPo

“I always pass on free advice — its never of any use to me” Oscar Wilde.

[Bret Williams]

In FCP 7 it puts the proper cadence on 60p when you drop in 24p. It’s a shame they can’t add interlaced pulldown when you add 24p to a 60i sequence. FCP X does a wonderful job. And I’ll assume Avid and Premiere. Not sure why legacy was never able to pull this off. So much wasted transcoding time.

[Jordan Shane]

Thanks for the responses guys. I have a few more questions regarding this issue. Tape has now been added to this project. So the specs are:

23.98 fps/ 640×480
29.97 fps/ 1280×1080
23.98fps / 960×720
59.94 fps /960×720

The majority of the footage was shot at 29.97 fps, 1280×1080. The finished film will be delivered for both DVD and web. The highest quality possible is important so I was going to continue with Shane’s original suggestion of converting all the 23.98 to 29.97 and working in a 1280×1080 timeline. Is this still recommended?

Also, regarding DVC Pro – I would prefer to work in Pro Res but the majority of the files are MXF. FCP 7 would only allow me to convert to DVC Pro (I believe it’s the only option), and when I tried a number of the MXF converters (to convert to Pro Res) they either didn’t work, or when they did and I tried to import the Pro Res, FCP 7 said it wasn’t a suggested file format.(strange) The producer does not want to spend the money on Calibrated or one of the other softwares so I figured I was left with DVC Pro. However if someone knows another solutions, I’d love to hear it.

Thanks so much for the help guys!!!