Understanding The Session File Structure


You may have noticed that when you create a new session, a folder is created which contains a number of files and additional folders, most people have no interest in what is going on here but it can never hurt to have an understanding of what is happening behind the scenes.

These folders contain each and every piece of the puzzle which makes up your session, from fade files to session backups, everything is organised in a very efficient way.

The name of the first folder created will be based on the name of your session, this acts as the ‘master’ folder and holds everything to do with your session.

So let’s have a look into all the contained files and folders and their purpose.


Session File

Each and every session will have a core ‘Session File’ with the extension ‘.ptx’ (Versions of Pro Tools prior to version 10 will have the extension ‘.ptf’, this file should be regarded as the brain behind the session.

Despite being deceptively small in size, this single file has a lot of work on its hands, every region placement, automation breakpoint, track height, track name… You get the idea, is stored within this file.

The folders which we will look at next act as an organised storage system for everything which the session file will call up into the session.

WaveCache File

The WaveCache file is another one of those files that gets a lot less credit then it deserves. Often overlooked, this file stores all of the data calculations related to the session and helps to load the session quickly.

If you delete the wavecache file, Pro Tools will regenerate the file, although this will take a little time when loading the session.


Audio Files Folder

As you will have probably guessed, this is where all recorded and imported audio is contained, this folder will also contain any audio which you may have processed such as regions which have had an audio suite plug-in effect applied to them, or a region with committed elastic audio changes.

Quick Tip: You will find us saying this a lot in many of our tutorials, naming audio regions prior to recording will make your life much easier later on when trying to locate certain regions. Region names will advance numerically from your track title such as Bass > Bass.01 > Bass.02 and so on…

Fade Files Folder

For pre version 10 systems, Pro Tools generates individual fade files rather than real time fades. Despite the fact a new fade audio file is created, the original information will still exist meaning that a fade can always modified or deleted without losing any of the original recording. Fade files are also one of the most secure files, by this I mean if you were to accidentally delete or lose a fade file, Pro Tools has the functionality to regenerate them again, not that we recommend you make a habit of it!

Region Groups Folder

To understand the contents of this folder it is probably best to read on up how region groups first of all, you can read our guide of region groups HERE.

As you will have hopefully read, region group information is stored within the session ‘.ptf’ file, it is only when they are exported that a new file is created with the extension ‘.rgrp’, these region group files hold a reference to the audio files and their placement within the group. When exporting a region group it will, by default, be placed within this folder unless otherwise changed.

Video Files Folder

There is a little more thought required when working with video files within your session in terms of how it is stored, video files can be rather large which means you may not have enough storage space to duplicate it into your session, most commonly Pro Tools will reference the session to wherever the video file is stored on your computer, however when it comes to fully backing up projects you will need to have the video file included. Whenever a video file is copied and stored within the session it will be located in this folder and all session references to the video file will be changed to this new location at the same time.

MIDI Files Folder

In the more recent versions of Pro Tools, there has been a much larger integration with Sibelius, MIDI information can now be sent directly out of Pro Tools into Sibelius for finer score adjustments, when this process is performed, the exported MIDI file is stored within this folder for safe keeping.

Rendered Audio Files Folder

When working with Elastic Audio there are a number of ways in which the changes can be applied to an audio region, elastic audio processing can either be performed in real time processing or as a rendered process, the benefit of real time processing is that changes can be made as you please, rendered processing saves the information within the ‘Rendered Audio Files Folder’ both of which will still utilise system resources so it is a common practice that when you are happy with your changes you can commit the elastic audio changes. Once you have committed to the change, the elastic audio plug-in can be removed and a new audio region will be created into the ‘Audio Files Folder’, at the same time the rendered audio reference file will get removed.

Session File Backups

Hopefully you will know of, and make full use of the ‘Auto Backup’ function within Pro Tools, this feature will save an updated version of your session based on time increments setup within the Operation section of your Preferences. Each and every session backup will be saved within this folder with the extension ‘.bak00.ptx’ (.ptf prior to version 10) and will increase numerically as the number of backups increase.

Test Yourself

If you would like to test your new knowledge of the Pro Tools session structure then why not head over to our quiz HERE and see how much new information you have taken on board!

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