2.6.x runs incredibly slowly

[danielrcollins1]

Describe the bug: OpenShot version 2.6 (both 2.6.0 and 2.6.1) run so incredibly slowly on my system as to be nonfunctional. Any preview clip runs at about 1 second of footage every 30 real-time seconds. Meanwhile, CPU usage stays close to zero (0-2% on four cores) throughout the process. This was not the case with prior versions.

Steps to reproduce the behavior:

1. Open OpenShot
2. Add any video to Project Files
3. Add that file to a track
4. Preview play the video

Expected behavior: A single short video track should play at normal speed, as was the case for any version of OpenShot up to 2.5.1 for me.

System Details:

• OpenShot Version 2.6.0 and 2.6.1
• Operating System / Distro: Windows 7 SP 1, Intel Core i3-3240 @ 3.4 Ghz, 8 GB, 64-bit

Log Files: N/A (not a crash)

Exception / Stacktrace: N/A

Screenshots: (Optional) N/A

[DanPinGF]

Looks like a duplicate of #4515.

[awunes]

Looks like a duplicate of #4515.

which is a duplicate of #4375

[DanPinGF]

Looks like a duplicate of #4515.

which is a duplicate of #4375

But #4375 is different! That issue has to do with audio output devices, and OpenShot can only handle one output source per session (see #4303). Removing or disabling the device simply induces the problem.

[awunes]

Looks like a duplicate of #4515.

which is a duplicate of #4375

But #4375 is different! That issue has to do with audio output devices, and OpenShot can only handle one output source per session (see #4303). Removing or disabling the device simply induces the problem.

Except #4375 doesn't have anything to do with audio output devices. It's literally only about opening the program, adding a video source, trying to preview it. You were the first to say it had to do with #4303 however the OP stated "That's not the problem." right after your post: https://github.com/OpenShot/openshot-qt/issues/4375#issuecomment-946323329

[DanPinGF]

Oh...

[braintweak]

Same for me. Win 10 Version 10.0.17763.2330 Ryzen 3600, AMD r9 280 gpu. 2.6.1 is a slideshow while previewing a an imported video. Old 2.4.4 I've been using for a long time has no such issues.

Tested OpenShot-v2.5.1-x86_64 - works fine. v2.6.1-dev-daily-8906-3c8dc71b-2b8b05c7-x86_64 has preview sped up and no sound, but at least not that laggy.

[robin-a-meade]

I had some luck after deleting the ~/.openshot_qt directory; preview speed returned to normal. (I use the openshot-2.6.2-0.1.20211104gitb72327d.fc35 package from rpmfusion on Fedora 35). Warning: deleting that directory will delete your OpenShot preferences.

[danielrcollins1]

I had some luck after deleting the ~/.openshot_qt directory; preview speed returned to normal. (I use the openshot-2.6.2-0.1.20211104gitb72327d.fc35 package from rpmfusion on Fedora 35). Warning: deleting that directory will delete your OpenShot preferences.

I just tried that on Windows 7. Fails to fix the behavior for me; OpenShot 2.6 still an unusable slideshow.

[DanPinGF]

I just tried that on Windows 7. Fails to fix the behavior for me; OpenShot 2.6 still an unusable slideshow.

Well, doing a fix that doesn't apply to your operating system won't work. The fix that @robin-a-meade did is perhaps a Linux-only thing.

[awunes]

Well, doing a fix that doesn't apply to your operating system won't work.

Doesn't hurt to try.

Though I had already tried and found further issues. See #4688 The last 2 daily builds fail to open. Also, the OP here was for 2.6.2 which isn't a thing for windows from what I can see.

[danielrcollins1]

Also, the OP here was for 2.6.2 which isn't a thing for windows from what I can see.

That's a good point. I tested against the most recent version (for Windows) which is what I assumed we were talking about. But indeed, that's 2.6.1, not 2.6.2.

[stale[bot]]

Thank you so much for submitting an issue to help improve OpenShot Video Editor. We are sorry about this, but this particular issue has gone unnoticed for quite some time. To help keep the OpenShot GitHub Issue Tracker organized and focused, we must ensure that every issue is correctly labelled and triaged, to get the proper attention.

This issue will be closed, as it meets the following criteria:

• No activity in the past 180 days
• No one is assigned to this issue

We'd like to ask you to help us out and determine whether this issue should be reopened.

• If this issue is reporting a bug, please can you attempt to reproduce on the latest daily build to help us to understand whether the bug still needs our attention.
• If this issue is proposing a new feature, please can you verify whether the feature proposal is still relevant.

Thanks again for your help!