How to solve Sluggish recording?

Some of my shotcut videos have shown some sluggish playback. Usually it doesn’t happen often, per video, nor many videos affected. Not sure if’s my Export settings, my PC’s limitations, or what. As I said, it doesn’t happen every video. As a result, I don’t know if this is a bug, or just seeking a suggestion, or how to!

However, the current project I’m working on, about an hour long video, with 3-4 different video clips of in game recording (Xbox Screen recording). Files were saved to an external storage (USB) from the console, and transferred to my PC, then transferred to my my WD My Cloud Ultra Pro 2 (A NAS device, 12T capacity, plugged into my router with LAN, accessed on my PC through my router WiFi).
I have a ASUS Zephyrus something, a ROG series laptop. Specs shown if needed. (White SS).

All this INFORMATION is just for context, if it’s needed to help determine if I’ve got proper settings, or have proper compatibility, or if it’s a problem with Shotcut, or what.

The video in edit contains 3-4 recordings mentioned, with multiple edits and filters as shown, and one audio file of my voice over talking, during the gameplay/recording, but it’s a separate file, as I often do my voice over recordings with headset through PC, using Audacity, while playing the game. Audacity file was exported as mp3 file, and attached to the project when I started it. The video is about 1h 20m long, with calm scenes of me talking and explaining things, and a few transitions, and many short battles sped up, using Shotcut properties on each video, 4x speed. All compiled into the completion of the rough draft. Exported as MP4 in shotcut.

These screenshots shown are me taking screenshots of Armoury Crate performance management, which comes built with my PC as an ASUS product. As seen, it shows details of my PC, and the stats shown were active during the shotcut rendering of the video completion, while over the window of shotcut rendering. If shown in order, you’ll see 1%, 6%, 16%, and 99% on the far right, showing the shotcut progress of the video, and each status of Armoury Crate in front was current at that time. I took the SS sporadically when I was able to look at the screen, but sense the projects take an hr on average to render/export to .mp4, I don’t stare at the screen the entire time, but stop in occasionally! I figure they would be helpful to determine if it’s a performance issue, and took the ss’ because I’ve noticed in the past, sometime it seems my PC struggles making the videos.




THE PROBLEM?
Upon watching the completed video in Windows media, the video starts getting sluggish mid way. Initially, the first few minutes worth seemed fine. about 5 minutes into the video, it’s as if the video freezes, only for a moment. It continues. Hopefully that’s the only issue, but it continues multiple times during the video. It seems, only during the times I’ve sped up the battles 4x speed. Usually this hasn’t been a problem. By the time I’ve watch 30 minutes of an 1h 20 min video, it’s shown skips, freezes, about 6 times maybe more.

I’m wondering if it’s a PC performance issue, is there anything I can do in shotcut to turn down demand of PC, and but allow a smooth recording? Am I putting too much demand with selected pieces of these clips at 4X speed? Or maybe another problem I’m not thinking of off hand?

Sorry for the long description. I know, I’ve been told before I am too detailed, but from my perspective, that’s the only way to get a point across. In this instance, I’m not sure what the problem is, so I’m sharing as much details as I can, so someone might recognize the problem.

It is not a performance problem. If your computer’s CPU is busy, the export will just go slower. The export does not happen in real time. So the computer can take all the time it needs.

These screen capture programs commonly use variable frame rate. VFR clips can result in unsmooth motion or audio/video sync artifacts.

You can post a screenshot of the properties panel for one of your clips to see if it might be VFR.

See the documentation here:

Sure can.
I took 4x ss’, were all consecutive clips below on timeline, the first 4 clips sped up! Parts between clip cuts were normal speed, 1x.

As far as I know, I leave all the details alone in properties, unless changing the speed, which I usually just change the 1x to whatever variable speed, in this case 4x. As far as aspect ratio, scan mode, metadata, or anything else on that property window, I don’t mess with any of it. Most of the time, it seems to have not been an issue, or too little of an issue to notice or worry about.




Thank you, btw!

The frame rate of your clips is 29.970052 - which is very close to the expected value of 29.97003. Your clips might be slightly variable.

As a test, here is my suggestion: pick a clip in your project that shows the “lag” in your exported file. In the properties panel hamburger menu, choose “Convert…”. Accept the default values and wait for the conversion to complete. Export the project and see if the sluggish effect is solved for that clip.

So… edit the properties for the one clip, export the entire project?

Or. cut everything else out of the video but the one clip!? Edit it’s properties, and export that short clip, not effecting the rest (basically a separate but shorter project)?

Another question. If its the VFR as your thinking/describing, if I cut out everything else, making small project for test, so a short only had that clip… but leave the properties as they are, would it still be sluggish? Assuming that’s the problem in the larger video completed, if it’s the only piece and un-edited, would it still cause the sluggish problems?

I suppose I can create a few test videos to find out, but thought I’d ask first if it’s expected to still be a problem. Leading to if this will solve it or not, or rule it out, is why I’m asking.

That is my advice. When you perform the “Convert…” on a clip, Shotcut generates a new clip from the original and then replaces the original clip in your project with the converted clip.

See the section “Converting VFR Clips” in this page:

Screen recordings become VFR and seem laggy when there are late frames or even drops frames, if it must, while recording because of other things going on. When that converts back to constant frame rate, the periods with late/dropped frames will instead have repeated frames. So, often conversion does not remedy the viewing experience, but it still provides determinism to make preview better match export.

I suppose reducing the project frame rate may help if there are only late or occasional dropped frames. The more severe the issue, the less effective it would be. It depends upon how sensitive you are, or if the problem is obvious to everyone. And yes you can edit the bad sections out, and that will be more reliable (predictable) if converted.


How should I proceed then with these options?

This is just to test if this is the problem.
I haven’t touched anything on this convert window yet, besides choosing Advanced to expand window.
the quality slider bar is at the lowest where it was.

Also. I already exported this short clip with a same name with test 001 at end. that export was done without any changes in properties. after I finished this convert, and save as test 002, and export, i’d watch both samples to see if any difference.
than go from there. I could make many of these samples adjusting each setting if I needed to, to run test samples against each other, but i’m not sure what effects each would have, and don’t know what i’m looking for, so that’s just why i’m asking before i do so.

Again, as I’ve opened this window, and taken SS, i have yet to make any changes or push Convert.

Do not change any options. Just click “OK”.

Exporting the clip will not have the same effect as using the convert function. I would not expect this to help.

No what i meant, was I made 001 as a sample for comparison. so if there’s a difference between the conversion, and what i previously had, i should see the difference, after i make 002 with conversion.

But for clarifying the other tip, thank you.

been converting a 2 min video, for 50+ min, only 57% through?? Is converting supposed to take this long?

SO… I’ve Converted, the file 3 times, it seems it’s restoring the cut out clip (15 min clip cut out from close to an hour or more source, than sped up 4x to show the 15 min in about 2.5 min, while I discuss it) with no cuts, and to 1x. Prior to Converting it, it’s only 2.5 min or close to, and already cut from original source (the 50+ min clip), and I open the properties window in the 2.5 min clip, and go through the conversion process, and it’s still reproducing the entire source clip?? Is that supposed to happen?

I’m guessing if I want to reproduce the 2.5 min cut, converted, I need to cut that from the reproduced converted source? than speed that up, and than Export to see if that sample is sluggish?

Yes, it is not an export; it does not edit; it only converts the source. If this was triggered while viewing the properties of a timeline clip, when the convert completes successfully, it replaces the source of the corresponding timeline clips from the original to the converted while keeping filters and speed changes.