Video Cadence Problem – 4:1/3:2

[Bouke Vahl]

well, the source files probably have been 24 P.
And somewhere they were reverse telecined, and somewhere the bad pulldown was added.
(besides, i don’t agree with this kind of pulldown to be suitable for air)

Now, if the cadance is consistent, it is easy.
Park on a frame just after the first duplicated, and go back as many multiple of 5 frames you can. (If you’re lucky, you end up on the first frame)

Do a QT export to 23.976 and QT will dismiss the added frames.
You then have a perfect file of the same duration, so you can paste in your original sound.
No pulldown, very suitable for digital, and you have the option to add normal pulldown for broadcast.

Now if there are cadence breaks, you need to do this per shot, so you have to razor the entire clip and do a batch export of all the clips.
Doable with a bit of scripting, but more work and hard on effects / transitions.

Bouke

https://www.videotoolshed.com/
smart tools for video pros

[Olin Padilla]

There is a difference between cadence and pull down. The pull down (where you wrote 3:2) is the pattern that 4 progressive frames are split into 10 interlaced fields. The cadence refers to a reference point for the pull down to start.

Your footage was probably shot at 24p with a 2:3:3:2 pull down. It is obviously very easy to confuse with 3:2, and means that one in every five frames is a duplicate.

To restore your footage to the original 24p, you need to run some kind of reverse telecine (in this case you need to remove 1 out of every 5 frames). Bouke’s method would be awesome if your video was that simple, but realistically there will be a cadence break at every edit point.

Then again, Bouke’s method of exporting shot by shot at 24p, is a lot simpler then any way I know to do it, and will probably be much easier to re-sync on a new 24p time line.

Just beware that the math isn’t going to be perfect here. After converting and re-importing your clips, you will have to go though meticulously and check for sync issues or small gaps in your time line.

[Mike Krause]

Sounds like your easy setup and/or sequence settings didn’t match your footage. I’m with Olin on the guess about the advanced pulldown as I deal with footage with similar end-result issues all the time.

There are a few of ways to fix this:

Long way is to go back to your original footage, verify the pulldown (normal 2:3 or advanced) and recut. (Yeah, didn’t think you had time for that)

Option 2 is Cinema Tools reverse telecine, but choosing the right frame pattern is hard (you do it by hand) and you need to work from a copy (copies!) of your final output since CT reverse telecine changes are destructive.

Option 3: if the pattern is rock solid consistent, drop your finished 29.97 w/ the 2:2:2:4 pulldown into a 23.98 sequence. It may take some fiddling, but the 23.98 sequence will discard frames in a specific pattern to fit the 23.98 frame rate. You’ll need to set your “in” on your element a few times probably and/or set your “in” in the sequence on different frames, but it works.

Option 4: JES Deinterlacer. Again you’ll need to figure out how to tweak the settings and set the removal pattern but it’ll work nicely.

Option 5: Bouke’s QT export trick (above), which is another good one.

Once you’re at a clean 23.98 “master” again, don’t use FCP to export to 29.97 if you need a 29.97 file, you’ll get that same bad pulldown pattern. Output to tape to get clean 2:3, or use Compressor to add it if you need to deliver a file.