Waveform is doubled up on cuts and zoom in / zoom out of timeline

[JamesRichards22]

Describe the bug: When viewing a timeline with the video as Waveform, on zooming in or out the waveform rewrites itself over to the top and doesn't refresh. This happens for cuts as well. In effect you see the old waveform, and the new zoomed one at the same time.

It seems to happen on longer files, and only when zoomed in quite a lot. There seems to be a point where it starts happening, but when zoomed out a lot it doesn't happen.

This seems to happens in the 3.3.0 Release as well.

Steps to reproduce the behavior:

1. Add a file to the timeline
2. Right click -> Display -> Show Waveform
3. Zoom in with mouse scroll or adjust the size of the blue timeline thing (not sure of the name)
4. See error

Expected behavior: Waveform displays as single waveform.

System Details: I'm using OpenShot-v3.4.0-release-candidate-13932-515c4ff5-0b018e34-x86_64.AppImage

Loaded modules from: /tmp/.mount_OpenShL5NdvE/usr/bin
INFO app: ------------------------------------------------
INFO app:             Mon Jun 16 21:03:49 2025            
INFO app:               Starting new session              
INFO app: ------------------------------------------------
INFO app:             OpenShot (version 3.4.0)            
INFO app: ------------------------------------------------
INFO app: openshot-qt version: 3.4.0
INFO app: libopenshot version: 0.5.0
INFO app: platform: Linux-6.14.0-15-generic-x86_64-with-glibc2.4
INFO app: processor: x86_64
INFO app: machine: x86_64
INFO app: python version: 3.8.10
INFO app: qt5 version: 5.12.8
INFO app: pyqt5 version: 5.14.1
INFO app: Frozen version info from build server:
{
    "build_name": "OpenShot-v3.4.0-release-candidate-13932-515c4ff5-0b018e34",
    "date": "2025-06-15 21:35",
    "libopenshot": {
        "CI_COMMIT_REF_NAME": "release-20250612",
        "CI_COMMIT_SHA": "515c4ff5099e516cb485c117a1927464c7a96d56",
        "CI_JOB_ID": "43399",
        "CI_PIPELINE_ID": "13931",
        "CI_PROJECT_NAME": "libopenshot",
        "SO": "28",
        "VERSION": "0.5.0"
    },
    "libopenshot-audio": {
        "CI_COMMIT_REF_NAME": "release-20250612",
        "CI_COMMIT_SHA": "0b018e347c7973e4253e29ec41394f3dfa87df4d",
        "CI_JOB_ID": "43309",
        "CI_PIPELINE_ID": "13911",
        "CI_PROJECT_NAME": "libopenshot-audio",
        "SO": "10",
        "VERSION": "0.5.0"
    },
    "openshot-qt": {
        "CI_COMMIT_REF_NAME": "release-20250612",
        "CI_COMMIT_SHA": "a616d424323cd9bd30b33ddbf09d82747ffb848a",
        "CI_JOB_ID": "43405",
        "CI_PIPELINE_ID": "13932",
        "CI_PROJECT_NAME": "openshot-qt",
        "SO": null,
        "VERSION": "3.4.0"
    }
}

Log Files: No output in the logs when this happens.

Exception / Stacktrace: n/a

Screenshots: Before zoom

After zoom

[Colorjet3]

@jonoomph this needs your attention

[JamesRichards22]

It happens on longer files, over at least 60 seconds, and only when zoomed in with waveform showing.

[Colorjet3]

Hello @JamesRichards22 I am running OpenShot-v3.4.0-release-candidate-13932 in Windows 11 Pro environment and I am unable to replicate this issue.

1. Does this happen with other .mp4 files as well or just this one?
2. Ensure that your display drivers are up-to-date?
3. Ensure that all your Windows and hardware related drivers are up-to-date?
4. Close OpenShot, if running.
5. Make a backup of c:\users\username.openshot_qt folder.
6. Delete c:\users\username.openshot_qt folder.
7. Start OpenShot and test again.

[JamesRichards22]

Hi,

I'm on Linux and I'm using the latest AppImage, which you can see in the log snippet from above. Starting with a fresh environment doesn't resolve the issue.I have AMD drivers that come with the Linux kernel, and I'm running OpenShot-v3.4.0-release-candidate-13951-22cd5633-0b018e34 and

Linux cog 6.14.0-15-generic #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

You need to use a longer video file, and zoom in quite a bit and then do a cut or ripple cut.

1. I used a 4.6GB 4K video file dragged onto the timeline
2. Go Display -> Show Waveform
3. I zoomed in a lot so I could clearly see the waveform

Way to reproduce this

1. Zoom in and out a little, the timeline rewrites itself

https://github.com/user-attachments/assets/c060efba-cf83-48a5-9758-b9ded92ff634

2. Do a cut and the timeline writes over itself

https://github.com/user-attachments/assets/ffb0f1f4-e5c1-411d-81e8-936b4eb3b8bc

But if you're zoomed out enough, or using a short video this doesn't happen.

https://github.com/user-attachments/assets/b8700e1e-1f83-4b37-b110-5dbdd581acec

[Colorjet3]

Thank you for all the details. Unfortunately I do not have a Linux environment that I can test in. I am also unable to replicate this in my Winodws 11 Pro environment.

I am going to ask the lead developer to review this and see if he has any ideas.

In general, are you able to still work with your project? Are you able to Export and things are good? I am asking to get an idea if this is just an issue during the editing/previewing but everythying else is ok.

[JamesRichards22]

Hi, yeah, I found for the longer files if I pre-cut them into shorter segments and the turning on waveform it works. I also logged #5796 because the large files with waveform don't perform very well.