Errors in headers of mp4 files

<img width="1470" height="920" alt="Image" src="https://github.com/user-attachments/assets/57890a42-29c0-41a2-8e80-95ba99fa4510" />

Some of the mp4 files can't be read, when FPS values are fetched. Need to check if those files are not corrupt, and if they are: delete them and download again (potentially manuallly, if pytube can't handle them for some reason).