Pro Tools Fundamentals - Pro Tools Session Structure

04-19-2014 11:00 AM

One of the most common mistakes I come across with new users of Pro Tools is confusion around the difference between the Pro Tools session file and the Pro Tools project folder. People who misunderstand the role of the Pro Tools session file (.ptx file) will at some point open a session and be presented with a missing files dialogue and ultimately a session with no audio present, just grey blocks showing where your audio would have been if it were available.

The Pro Tools session structure uses an “edit decision list” which references assets elsewhere on the system. However if you’re making the mistake described above that explanation probably isn’t helping so a different approach might be more helpful.
Where are the assets?

Most people are familiar with Word documents (other word processors are available…). There is a document file on your computer and if you want to backup, move or share that document you just locate it and take it with you. This works because a word document is monolithic - i.e. everything in that document is stored in that single .docx file. If the document is all text then this is all very unsurprising but what if you import an image? For the sake of this description think of the image as an asset (i.e. a thing which belongs to that document) does the image file get mixed together with the body of the text in this one .docx file? In this example it does, and the advantage of this is that file management is straightforward. The downside of this monolithic way of doing things is that if you wish to make an alternative version of your document with different text but the same image, you will end up making a second copy of the image with that second version although the two images are identical.

This duplication of assets is not a problem if you are working with jpegs which are a few kilobytes in size but the bigger your assets are the greater the benefit of referencing your assets. Referencing assets is an approach where instead of including the asset in the file the file contains a reference or link to the file to be used. An advantage of this approach is that multiple references can be made to the same asset from many different files without any additional copies being made. With modern cheap, large hard drives you could argue that for the majority of users a monolithic file structure which bundles up the assets with the file would be better but the Pro Tools file structure has been around since a time when storage was expensive and for large projects and collaborative workflows this referenced system is still the most effective.

The image above shows the Pro Tools project structure. There are lots of useful things in there, if your file management is at all in question you should definitely investigate the session file backups folder. The only really important parts for this discussion are the project folder itself (in this case “PT File Structure Demo”), the Pro Tools session file (the .ptx file) and the Audio Files folder. The really important thing is that your Pro Tools project is the whole session folder, not just the session file. The .ptx file is just a list of references to the files in the audio files folder (as well as, amongst other things, mixer and plug-in settings and any midi your session contains).

Things you need to know to stay out of trouble with Pro Tools file management:

  1. Don’t move or copy a .ptx file on its own unless you understand exactly why it is OK to do this (there are lots of times it is fine but if you don’t know when they are just leave it in the project folder).
  2. If you want to copy or move a Pro Tools session move the project folder, not the session file.
  3. Don’t make any changes to the contents of the audio files folder from Finder. If you want to remove files it should be done from the clips list in Pro Tools.
  4. If you want to back up or move your session to another computer then save a copy from the file menu and tick the include all audio files checkbox and move the copy not the original