Midi Offset Remover

This tool removes empty spacing before the first midi event.

Problem

If you export a Midi region as a Midi file in Logic Pro, the position of all Midi events in the Midi file are absolute and not relative.

What does that mean? If you have a Midi note or Midi command in a Logic Pro project at minute 02:00:00 and you make a Midi export, starting at that note, the resulted Midi file will include a Midi Note at minute 02:00:00. What we want is a Midi note at 00:00:00. This tool transforms the Midi notes/cc/program changes according to that.

Midi file before:

Example data

Midi Channel	Midi CC	Time	Time diff to note before
2	1	02:30	-
2	2	02:40	00:10
3	3	03:00	00:20

Midi file after:

Example data

Midi Channel	Midi CC	Time	Time diff to note before
2	1	00:00	-
2	2	00:10	00:10
3	3	00:30	00:20

How to use

Setup

1. Clone repo
2. Run yarn to install packages
3. Install py-midicsv pip install py_midicsv. This project uses its command line tool

Run

1. Create an empty folder and put your Midi files in there which you want to be transformed, e.g. /Downloads/TRANSFORM_MIDI
2. Run yarn start <your_directory> or sh midi-offset-remove-all.sh <your_directory>. Following the example, it would be yarn start /Downloads/TRANSFORM_MIDI
3. All files will be transformed. The new files will be places in the out directory inside the same folder.

Hint

• Keep in mind that the first event in the source Midi file will always be at time 00:00:00 in the new file.
• You can also setup Automator (Mac) to auto-transform files as soon as you put them inside the folder.