It’s literally impossible to play at 23.976 file in 29.97 timebase. That’s like saying “if I go 50mph, I am really going 55mph.” It’s impossible because of what things mean and how they are. In some contexts, we manipulate different timebases and playback to create overcrank or undercrank. Mostly, though, the computer assumes editors want persistence of vision, so it will render the clip to whatever the sequence settings are. There are literally more frames of picture at 30fps than there are at 24fps. So the computer has to play that bit faster. When footage is interpreted, then the audio associated with that particular clip will also be interpreted. It will playback either faster or slower. It’s probably unwise to deliver a wedding video of the bride and groom sounding like chipmunks.
Premiere helps us out. In the sequence area, just below the timecode marks, you will see a red, yellow, or green bar.
Red means “this footage needs to be rendered.”
Yellow means “this footage does not need to be rendered but it is processor intensive.”
Green means “this footage is rendered and export will be quick.”
We always want green render bars. If they are not green, then render the sequence, and you will create NEW MEDIA of the correct timecode.
Since you will be making new media anyway (the render files of the time code), it is BEST PRACTICE to transcode first.
If you have any sync sound (like exchanging vows or first dance, etc) then use the A camera footage as your sequence. That means, all the footage that is not in that exact format needs to be transcoded to that exact format of the A camera..
This is a relatively painless process, but it can be shocking because your amount of media is about to double (but again, it will double anyway because you will make renders of it all anyway, and if you do any color correction you will make renders of the renders and so on).
TRANSCODE FIRST USING ADOBE MEDIA ENCODER. If you’ve already started cutting. Stop. Transcode.
Here’s how:
1. Memorize, write down, or screen cap the target codec from Premiere’s Project Pane.
2. Open Adobe Media Encoder. In the bottom right is a window called WATCH FOLDERs. If you can’t see it, then turn it on in the window menu.
3. Hit the + button and navigate to a place on your media drive (probably in the same folder as your project)
4. The drop down arrows allow you to chose the EXACT FORMAT from step 1.
5. From the finder/explorer, drag 1 and only 1 (for now) of your original media into the newly created watch folder. (Open Adobe Media Encoder, if it isn’t already.
6. In Premiere Pro, use the Media Browser to import the newly transcoded files into Premiere and compare their settings. If you did everything correctly, then the settings should all match. Right click a piece of the targeted media and choose “New Sequence from Clip.” It should be either green or yellow. We can live with yellow. Then add a file from the newly transcoded footage into the sequence. It should also be yellow. If it is red, something is mismatched, and you’ll need to transcode again. When you have the settings correct, drag all that footage to the watch folder.
7. Grab some lunch while the footage transcodes.
8. It all lands in the output folder, so now Media Browser that folder into Premiere.
Believe it or not this is an overview. Haha! So if you need more detail, just ask, and I will post pictures.