Add sources
Choose File → Import Media (⌘I) and select the files. Meridian reads their media properties and adds admitted sources to the library. Watch Background Tasks for progress and individual failures when importing a batch.
An extension such as .mov describes a container, not every codec it might hold. Read the error for the specific file if it cannot be imported.
Review the library
Use the Video, Images, and Audio filters to narrow the browser. Open a source and check its picture, duration, and sound before using it. A thumbnail is a browsing aid; playing a representative range is a better check of the source.
Keep original media in a stable location. If you move it later, use relinking rather than importing an accidental second copy and expecting existing timeline references to change.
Recover a partial import
Review which files succeeded. Retry the failed items after resolving their file access or format issue. Keep source originals when creating alternative encodings, and check the alternative’s timing and audio before using it as a replacement.