pat is correct as Media Composer manages the sources differently than what a DI or other third party system might use depending on source file, and REEL name preferences, etc.
When using AMA or importing, all filenames are tracked in the “Source File” column. If captured via Tape, or via an ALE import first with Tape, or made in a third party system such as Resolve or Redcine X Pro, then the filename will be in the TAPE column.
It is possible for a project to be tracking sources in both TAPE and SOURCE FILE.
When generating an EDL, the process is:
1. Use value in TAPE. If none found then:
2. Use value in SOURCE FILE
So there should always be a value in either of those columns to track source via EDL. EDL Manager also allows the user to insert values found in Labroll, Camroll, and Soundroll should the source file allow for different naming as with ProRes from an ARRI Alexa; full filename or REEL from QT Header).
If using AAF, then the AAF contains all the metadata and it is up to the receiving application to parse the proper fields. That is why you want to test it with that application. Also note, that if using AMA and the sources are still linked (live), then you cannot generate an AAF without first checking the “use edit protocol”.
Michael