Will this show that there is a moov atom even if it's incomplete?

For example. if the full moov atom was 6mb but only 3mb of it had been downloaded, would `qtfaststart-l file.mp4` show that there is a moov atom even though it's incomplete and if so is there a way to check if it is complete or not?

Start with the qtfaststart-l command and inspect how it parses the moov atom in file.mp4. Verify what happens when the atom is only partially downloaded, then document whether the command detects incompleteness and how completion can be checked.

Written by the indexing model from the issue text.