Convert 30i Footage to 24p with After Effects

There’s something magical about 24 frames per second video.  It just feels more natural and “film-like” than 30.  To me, 30 fps can make even well produced videos feel like cheap TV sitcoms.  24 fps has a much more professional look and feel to it.  I am by no means saying “OMG 24 fps = teh big screan mooveez!!1!” and I’m not about to get caught in the crossfire of the never ending “You can’t tell the difference between those 6 missing frames” debate.  Truth be told, the average viewer probably can’t see the difference, and I’m certain it is just because of my video editing background that I am able to.  Still, I’ve been searching for years on how to convert 30i to 24p because unfortunately, my camera only shoots 30i.  So you can imagine my excitement when I stumbled across Andrew Kramer’s frame rate converter tutorial for After Effects.  Hold it, don’t get excited just yet, it doesn’t really work.  I love Andrew’s tutorials, but this one has never worked well for me.  The video always comes out with really strange artifacts and random, completely garbled frames.  And if you try to convert an already edited video, each edit will result in more contorted frames.  This is on top of incredibly long render times.  On a decent computer, a 30 second clip might take 2 plus hours to render.  It’s that bad.  Which is why I decided to find a better method, particularly one that didn’t cost money.  First I should note that I can’t take full credit for this method because I’m still using one of Andrew’s tutorials, just not the one relating to frame rate.

So to begin, you should have:

• A 30i video to convert
• Adobe After Effects
• Andrew Kramer’s scanlines.psd from the “Deinterlace in AE” tutorial

To get the scanlines.psd, go here and download the project file.  Andrew has included scanlines for both SD and HD footage, so you can apply this method to either format.  These beginning steps are taken directly from Andrew’s deinterlace tutorial, so you can either follow along here, or watch the video on videocopilot.net for more in depth explanation.  If you do want to follow Andrew’s video, complete steps 1-5, then do Andrew’s tutorial, then skip to step 14 of this tutorial.  Or, skip to the bottom and watch the tutorial I made.

1. Create a new After Effects project.
2. Import your 30i video.
3. Right click on the video and select interpret footage–>main
4. In the pop up select “conform to frame rate” and enter 23.976 in the input box.
5. Change “separate fields” to off, then click OK.
6. Drag the video down to the “new comp” button to create a composition with the correct settings and length.
7. Import the “scanlines.psd” file into After Effects and place on the top layer of your composition.  You may need to scale it horizontally to cover the entire video.
8. Set the track matte on the video layer to “luma matte”
9. Precompose these layers.
10. Duplicate the precomp layer.
11. On the bottom layer apply a directional blur effect with “1.0″ length.
12. Also on the bottom layer apply a levels color correction effect.  Change the channel to alpha and pull down the highs near the bottom until the video looks solid.
13. Add an adjustment layer to the top of the composition and apply another directional blur this time with “0.5″ length.
14. Precompose all of these layers.  Now you should have a really nice deinterlace, thanks to Andrew Kramer.  It is important to use this method of deinterlacing.  If you let After Effects do it, you will end up with very flickery footage in the end.
15. Right click on the precomp layer and select time–>time stretch, then change the duration percentage to 80 and click OK.  You can either trust me that it is 80% or conduct your own experiment to find out.  If you do this process with a clip that ends in a nice rounded off time (no frames, only minutes/seconds) and instead of changing the percentage in this step you enter the actual duration of the clip, you will see that it is in fact 80% exactly.
16. Add the original footage to the bottom layer of the composition.  Turn the video off for this layer, and turn the audio off for the precomp layer.
17. Trim the timeline to the duration of the precomp clip.
18. Pat yourself on the back, because that’s all it takes.  You can now export a 24p video.  The nice thing about this method is that you can edit your video in 30i then simply convert that to 24p after.  Of course you could always convert the raw footage to 24p before editing, but that may be impractical depending on the amount of video.
19. If you are exporting to an AVI, which I would assume you will, make sure you turn the audio on and change the compression type to “Microsoft DV”.  If you don’t change it to Microsoft DV it will export squished into 4:3 aspect ratio.

Update: To be honest I didn’t really know what I was doing when I wrote this tutorial.  So here’s an explanation.  This method is a lot like the “posterize time” method in that it drops every fifth (I think) frame.  The difference is that this method actually produces a 24 fps video instead of a 30 fps video that looks like 24 fps.  This works, but it doesn’t provide the smoothest results.  You may like it, you may not.  If you want it smooth you can enable frame blending and use pixel motion for some pretty good results.  The only problem is this will now result in garbled frames on edits.  So you can’t use frame blending with an already edited video, but you could use it on raw footage.  That could be pretty impractical though, as frame blending adds a considerable amount of time to rendering.