Random very short choppy video - pannig.

Question

Level 1

4 points

Random very short choppy video - pannig.

4K 30fps video from iPhone 14Pro is smooth, but after rendering in FCX it is randomly stuck for a very short time mainly during panning or during shots from a moving car. This is a very short video stutter and it is random in different shots. Mostly in panning or shots through the windshield of a car. It resembles a drop frame, but the original mov video is ok.

I have the latest version of FCX and iPhone 14 Pro. The original video from iPhone does not contain it, but the render in Compessor does. Interesting, the iPhone 13 Pro did not do this. Don't know where the error is. Thanks. Jirka.

Posted on Feb 22, 2025 10:36 AM

Reply

Answer 1

BenB

Level 6

12,799 points

Feb 25, 2025 2:37 PM in response to terryb

I record 30fps at 4K across iPhones from 10 - 16 and don't have this issue, when the timeline is also 30fps. I've not noticed iPhones set to 30fps recording at variable frame rates, either.

I'd like to see the clips themselves, how fast is this panning? May simply need to slow it down when shooting? Text that out.

Are there any effects applied or titles on top of these specific clips?

Reply

Answer 2

jiri73 Author

Level 1

4 points

Feb 25, 2025 7:19 AM in response to terryb

original MOV from iPhone 14 Pro is OK, but rendered video has random very short stutter like 1-2 frames drop or very short move back ..with iPhone 13Pro was it ok. Thank you for Your help. Jirka, Prague

Reply

Answer 3

terryb

Level 4

2,820 points

Feb 25, 2025 1:34 PM in response to jiri73

I believe the iPhone Camera app records with variable frame rate which FCP does not like. Try optimizing one of the shorter clips that exhibits the issue and see if there's any change. Note that optimizing can create large ProRes files so be sure you keep an eye on disk space.

Reply

Answer 4

jiri73 Author

Level 1

4 points

Feb 25, 2025 7:16 AM in response to terryb

sending FCP settings and compressor render settings:

Reply

Answer 5

terryb

Level 4

2,820 points

Feb 22, 2025 12:10 PM in response to jiri73

What are the FCP project specs? What are the Compressor render settings? You're sharing to a Compressor preset?

Reply

Answer 6

jiri73 Author

Level 1

4 points

Feb 25, 2025 7:22 AM in response to terryb

iPhone 14 Pro camera settings : 4K30 FPS, automatic FPS -off

Reply

Answer 7

jiri73 Author

Level 1

4 points

Feb 25, 2025 7:30 AM in response to jiri73

! Problem is already on timeline preview in FCP before rendering. But original file played in Quick time is without this problem...

J.

Reply

Answer 8

jiri73 Author

Level 1

4 points

Feb 26, 2025 12:34 AM in response to terryb

I think also that quickly changing scene can resulte in lower frame rate and FCP has problem with it ... but problem is probably in source file iPhone 14Pro mov file. thanx for your help. Jiri

Reply

Quick Links

Random very short choppy video - pannig.