Occasionally, you may come across an MP4 file that Lostify will fail to read. Lostify may complain that it’s an invalid MP4 file, but this is not always the case. It may simply mean that while trying to read the existing metadata, Lostify encountered something unexpected and gave up.

In the future, I’ll continue to try to loosen up Lostify’s parsing code, so this happens less and less. I’ll also probably add a “repair file” command to Lostify for serious cases where the metadata may actually be unreadable by AtomicParsley. But in the mean time, you can repair these files manually using AtomicParsley, the command-line tool upon which Lostify is based.

Here are some instructions for doing this type of repair, assuming no prior knowledge of how to use Terminal. If this is your first foray into Terminal, however, please take care to follow the instructions closely!

1. In Finder, go to where you’ve got Lostify saved. Control-click the Lostify application, and choose Show Package Contents.
2. In the new Finder window that comes up, navigate to Contents:Resources. The first file in that list should be AtomicParsley. Leave this window up where you can get it later.
3. Back in the original Finder window, navigate to where you can see the MP4 file you want to fix. Also leave this window up where you can get it later.
4. Open a Terminal window (Applications:Utilities:Terminal.app).
5. Drag AtomicParsley from the Resources window in step #2 into the terminal window. The unix-style path to that file appears at the Terminal prompt, followed by a space.
6. Now drag the MP4 file you want to modify from the Finder window into the same Terminal window; its unix-style path is appended to what you did in the previous step.
7. Now append an instruction onto the end of the command you’re building in the Terminal window:If you want to clear all existing metadata out of the file, type
   

   -P

   Or if you only want to reset the Copyright tag, for example, you could type

   --copyright 'some new copyright text'

   There are lots of commands you can give to AtomicParsley; AtomicParsley will list them out for you if you simply follow steps 1-5 above (to invoke AtomicParsley by itself with no parameters).

8. When you’re done building the command, press Enter and the AtomicParsley program should execute the command you requested on the MP4 file. If everything was entered correctly, it should say something about writing to a temp file.

The output file will appear in the same directory as the input file, with the same name and “-temp-12345″ (actually a random number) appended at the end of the filename. This output file should now be able to be read by Lostify again; the input file should remain unmodified.

I hope this helps folks who have, for one reason or another, encountered MP4 files that Lostify fails to read!

This entry was posted on Saturday, January 19th, 2008 at 5:49 am and is filed under Tips & Hints, Lostify. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.