Comment 6 for bug 696863

Trying to import that many clips in one go is going to take some time - for each file that is imported, an Openshot file object is created, an instance of MLT is created to obtain various properties of the file, these and other properties are set on the file object, and a frame is extracted from the clip to use as the thumbnail image - it is an intensive process.

There haven't been any changes in this area in 1.3, or with regards to files having the same ID.