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Participating Frequently
June 22, 2022
Answered

Why is Adobe software reading a video clip with the incorrect duration?

  • June 22, 2022
  • 3 replies
  • 2105 views

Let me preface this by stating that this issue applies to Premiere Pro, After Effects and Media Encoder; I have not tested it with any other Adobe software.

 

A bit of background information: I have a piece of stock footage that runs at a constant 23.976fps as expected. I work in a cross–platform environment, and it's not uncommon for clips to be used in multiple NLEs. Typically, when dealing with a variable frame rate clip, including stock footage, Premiere Pro will have a slightly different (shorter) length than other editing software, which I've come to expect, but I have never had this problem with a constant frame rate clip before.

 

If I load this clip into any other NLE, it is exactly two frames longer than it is in Premiere Pro/After Effects/Media Encoder, despite the fact that there's no reason why it should be any different in Adobe's software than in other editing tools. Does anyone know what might be causing this? I've taken this piece of stock footage and run it through multiple programs, and only Adobe is missing two frames. If I create a timeline from the clip, I cannot drag it out by two frames, so it's not as if the frames are just "hidden," the clip is simply interpreted as being two frames shorter in Adobe's software than it is in anything else, despite being a constant framerate clip.

 

I'm running Adobe CC 2022 on an M1 iMac, but have also tried this in Adobe CC 2021 on an M1 iMac and a Windows desktop. The specs for the iMacs are 16GB RAM, 2TB SSD and macOS Big Sur; the Windows machine has an Intel i9-7980X, 128GB RAM, GeForce GTX 1080, and runs Windows 10. Platform doesn't make a difference to this issue. Any assistance would be appreciated.

This topic has been closed for replies.
Correct answer Jeff Bellune

If you look at the MediaInfo report, the overall file duration is 7s, 603ms. The audio is also 7s, 603ms.

But if you look at the video duration, it is 7s, 508ms.

2 frames at 23.976 fps is about 84ms. Add the 14ms that it shows as last frame duration in the audio section and you get 508+84+14 = 606ms, which is really close to the 603ms reported by MediaInfo.

The discrepancy in the audio and video duration in the file itself can account for the different durations reported by different apps.

3 replies

Community Expert
June 23, 2022

Right-click on variable frame rate clips in the Finder and choose "Encode Selected Video Files" to transcode the clip to a constant frame rate.

 

You're conforming everything to ProRes to take advantage of Smart Rendering in Premiere Pro and the ProRes encode and decode engines of the M1 hardware, right?

Participating Frequently
June 23, 2022

This particular clip isn't variable framerate, hence why this issue is so baffling. We're not conforming everything to ProRes, at least not at this stage. Right now my concern is with the clip being two frames off in Adobe's software vs. all other tools, not with render speeds.

Jeff Bellune
Brainiac
June 23, 2022

Are you using hardware *decoding*? The way Pr decodes the H.264 stream may cause the frame count variance.

Jeff Bellune
Brainiac
June 23, 2022

Please post a screenshot of the text output or tree view of MediaInfo for the problem clip.

Participating Frequently
June 23, 2022

 In Premiere Pro/After Effects/Media Encoder this file displays a timecode duration of 00:00:07:12. In all other software that duration is 00:00:07:14.

Jeff Bellune
Jeff BelluneCorrect answer
Brainiac
June 24, 2022

If you look at the MediaInfo report, the overall file duration is 7s, 603ms. The audio is also 7s, 603ms.

But if you look at the video duration, it is 7s, 508ms.

2 frames at 23.976 fps is about 84ms. Add the 14ms that it shows as last frame duration in the audio section and you get 508+84+14 = 606ms, which is really close to the 603ms reported by MediaInfo.

The discrepancy in the audio and video duration in the file itself can account for the different durations reported by different apps.

R Neil Haugen
Brainiac
June 22, 2022

Wondering if this is a drop frame/non-drop frame issue? Not an expert on that sort of thing though ...

 

Neil

Everyone's mileage always varies ...
Community Expert
June 23, 2022

For it to be a drop frame / non-drop frame issue, it would have to be running at 29.97 instead of 23.976 and the clip would be between one minute and two minutes in duration to be off 2 frames.