Glitch after cut between clips

[MartynMoore]

Hi Adobe Community

I have a two-camera interview on my timeline: MXF clip from a Sony FS5 on V1 and MP4 clip from a Sony A6400 on V2.

When I cut from V2 to V1 I get a glitch (see clip with still). I have found a workaround which involves removing the clip from V1 when V2 is active and then extending the start of the next .MXF clip to under the active .MP4.

I'd rather not have to do that; there may be instances when it's impossible.

Any clues?

Martyn

[Ann Bens]

Did not mention Premiere version and build. OS or comp specs.

If you are using a nvidia card make sure you have the most current Studio driver installed.

[MartynMoore]

Sorry Ann. Premiere Pro version 24.5.0 (Build 57). Windows 10 Pro. Intel i9-7900X CPU @3.30GHz, 64GB RAM, GeForce GTX 1080 Ti, NVIDIA Studio Driver 555.99.

[PaulMurphy]

Were both cameras shooting at the same frame rate? Does the issue go away if you have a black matte under everything on the first track?

On a side note, I recommend editing shoots with multiple cameras using a multi-camera source sequence. It allows you to edit on a single track while easily switching between cameras. Check out this guide for more details: Creating Multi-Camera Source Sequences.

Cheers,
Paul

[MartynMoore]

Hi Paul. Yes, both cameras were shooting at 25fps.

Do you mean a black matte on V1 and then footage on V2 and V3? I've never tried that but will give it a go if the problem persists. Can you explain your thinking on this, please?

Curiously, when I reposition the start of the clip on V1 to the end of V2 now, like it was in the original edit, the glitch has disappeared. I get the feeling it's to do with Prem Pro accessing the file, for some reason. But I have identical edits elsewhere in the timeline and they play and output fine.

Thank you very much for the suggestion to create a multi-camera source sequence. I will certainly do this for my next project. So far I've not had a problem working on multiple tracks, so have never tried it. Time to learn and improve!

[PaulMurphy]

Hi Martyn,

Yes, I'm suggesting adding a black matte on V1 with footage on V2 and V3. This helps determine if the overlapping footage is actually fixing the issue or if any footage has the same effect.

To me, the glitch looks like a long GOP encoding error. This can happen when exporting to a low-bitrate H.264 using source files that are also H.264. These kinds of glitches usually occur around edit points. If this is the case, I would suggest exporting to something like ProRes first, then convert your ProRes to H.264 or whatever your delivery format is.

Hope this helps! If you have any more questions, feel free to ask.

Cheers,
Paul

[MartynMoore]

Thanks Paul. The glitch appears in the Program Monitor when playing back on the timeline and I'm now seeing it on projects where I only have one track of clips, all MXF from the same camera. So the multi-track/camera set-up might be irrelevant. See my new image.

Playing the original file in VLC it looks fine. So I made a copy of it, imported the copy and replaced the clip and it works fine. However, a glitch then appeared in the clip immediately before it! I saved the project and the glitch was back on the next clip. I changed Playback Resolution to Full and the glitch was gone again. I've output the file and the glitch is gone on the .mp4 output.

Summary:

• The glitches appeared in the Program Monitor when editing and in the output file.
• For a while, when I placed the playhead on the first frame of the glitch clip, the glitch was only minor, then after a second it got much worse, without moving the playhead. It did this every time. Then it started to just show the constant glitch.
• Copying the original file outside Prem Pro file, importing it through Media Browser and replacing the clip moved the glitch to the preceding clip.
• Saving the project moved the glitch back to the original clip.
• Changing the Playback Resolution seemed to have fixed all glitches. The whole timeline played glitch-free and the output was clean.
• Playing an MP4-only timeline at full resolution is now laggy.
• Reverting to the glitchy timeline, the glitch is now back and changing the playback resolution doesn't help this time.
• At first, lifting the clip out of its position in the edit and dropping it at the end gave clean playback; when I put it back in place in the edit the glitch is back. Now it glitches in and out of its position in the edit.
• Replacing the new copy clip with the original clip has now fixed the glitch. I've saved the project and closed it.

Who knows what will happen next time I open it?

[Averdahl]

The glitch appears in the Program Monitor when playing back on the timeline and I'm now seeing it on projects where I only have one track of clips, all MXF from the same camera.

By @MartynMoore

What happens if you enable Full Playback Resolution in the Program Monitor instead if 1/2? If that does nothing, click on the wrench and make sure to tick High Quality Playback in the menu that pops up.

Maybe it does close to nothing since from what i gather you get the same glitches in your exports as well. (?)

Are the same glitches in the export present if you export with the setting in the second image i attached? Try it and see if it makes any difference.

Another thing to try is to go to Edit > Preferences > Media and un-check both H.264/HEVC hardware accelerated decoding and H.264/HEVC hardware accelerated encoding and then save/close and restart Premiere Pro.

Yet another thing to try is to go to File > Project Settings > General and set the Renderer to Mercury Playback Engine Software Only and click OK.

[MartynMoore]

Thanks very much Averdahl. I will try your suggestions.

I am seeing the same glitches in the Program Monitor as I am getting in my outputs.

Many things seem to affect the glitches: Program Monitor resolution; moving the clip out of place in the edit and then returning it; opening another sequence has made glitches come back. If I export a sequence that doesn't have glitches when playing back from the timeline, then I don't think the output file has the glitches.

I am monitoring my outputs very carefully now, as you can imagine.

This afternoon I have been editing clips from the same camera but in a different project and have not seen any glitches so far.

Fingers crossed!

[MartynMoore]

And to add to the clue-gathering, a recent upgrade of Premiere Pro coincided with an issue with dropped frame errors on MXF files only. Unfortunately, this occurred around the time I exported a project to work on a laptop on location, then exported it again to finish it on my desktop. So I don't know if it was this or the new version of the app that caused the problem.

Clearing the media cache seems to have fixed the dropped frames errors. Not sure if any of this helps...

[Averdahl]

By @MartynMoore

See my post abowe. I see that it landed in the wrong spot in the thread...