Label-studio slow for longer video (+2 minutes, mp4)

**Describe the bug**
I have tried different videos (mp3) for 16sec, 2mins, 5mins, and 10mins for importing into Label-studio to label objects in the video. For the first two videos, the import is completed in less than a minute. However, it is not responding and keeps running for the later two videos with more duration.

Is there any one who had the same issue and solved?

**To Reproduce**
- created virtual environment and activated
- Installed Label-studio locally using pip install label-studio
- Launched label-studio from terminal
- From Label-studio UI, created a project configuration, import the video
- Tested on Window and VM Ubuntu (both the same result)

**Expected behavior**
- I expected the video to be imported.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (please complete the following information):**
- OS: [e.g. WIndow 10, Ubuntu 20]
- Label Studio Version [e.g. 0.8.0]

**Additional context**