XPJ Utils

Tools to manipulate XPM files from modern Akai workstations (Akai Force, Akai MPC series)

XPJ file format

A XPJ file is a gzipped text file basically serializing a big JSON structure.

The format is as follows, once gunzipped:

ACVS\x0a<ProgramVersionInAscii>\x0a<KindOfFile>\x0a<FileFormat>\x0a<ProductionPlatform>\x0a<Payload>

The first characters are "ACVS", the program version is a text string of numbers, the kind of file is "SerialisableProjectData", the file format is "json", the production platform is "Linux" for my example, and the payload is a simple JSON string.

Manipulating XPJ data

gunzip the file, make the changes you want, gzip the file, you're done. This python library helps with that.

Filter architecture for keygroup

The keygroup architecture is as follows:

• A keygroup instrument is made of keygroups
• Each keygroup covers a potentially overlapping keyboard range
• Each keygroup is made of 4 layers, potentially empty. A Layer will hold info about how to play a given sample
• In a keygroup track, each keygroup is considered its own instrument, and because of that:
  • Each keygroup has a unique filter settings set for it

Because of that if you want to control filter parameters for your entire keygroup, you need to drive several parameters at once.

I want to automate my filters, how do I do it?

• Step 1: save your .xpj, back it up, no warranty in case of data loss.
• Step 2: copy your .xpj to your computer and load this program
• Step 3: run python -m xpjutils <your-xpj-file> make-mapping-template <path-to-yaml.yml>. This will scan any drum/keygroup track and prepare a template item for each of them.
• Step 4: edit path-to-yaml.yml and set the right midi CC codes for your device and for each track.
• Step 5: run python -m xpjutils <your-xpj-file> change-mappings >path-to-yaml.yml> <new-xpj-file>
• Step 6: copy to your MPC/Force overwriting the original xpj file.
• Step 7: see that it works.