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Extract the melody from an audio file and export to MIDI
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Latest commit 988b3e5 Apr 24, 2019


Extract the melody notes from an audio file and export them to MIDI and (optionally) JAMS files.

The script extracts the melody from an audio file using the Melodia algorithm, and then segments the continuous pitch sequence into a series of quantized notes, and exports to MIDI using the provided BPM. If the --jams option is specified the script will also save the output as a JAMS file. Note that the JAMS file uses the original note onset/offset times estimated by the algorithm and ignores the provided BPM value.

Note: extracting a MIDI melody from a polyphonic audio file involves two main steps:

  1. melody extraction
  2. note segmentation.

Melody extraction is the task of estimating the continuous fundamental frequency (f0) of the melody from a polyphonic audio recording. This is achieved using the Melodia melody extraction algorithm, which is the result of several years of research. Note segmentation is the task of converting the continuous f0 curve estimated by Melodia (which can contain e.g. glissando and vibrato) into a sequence of quantized notes each with a start time, end time, and fixed pitch value. Unlike Melodia, the note segmentation code used here was written during a single-day hackathon and designed to be as simple as possible. It will most likely not provide results that are as good as those provided by state-of-the-art note segmentation/quantization algorithms.


>python infile outfile bpm [--smooth SMOOTH] [--minduration MINDURATION] [--jams]

For example:

>python ~/song.wav ~/song.mid 60 --smooth 0.25 --minduration 0.1 --jams


usage: [-h] [--smooth SMOOTH]
                                [--minduration MINDURATION] [--jams]
                                infile outfile bpm

positional arguments:
  infile                Path to input audio file.
  outfile               Path for saving output MIDI file.
  bpm                   Tempo of the track in BPM.

optional arguments:
  -h, --help            show this help message and exit
  --smooth SMOOTH       Smooth the pitch sequence with a median filter of the
                        provided duration (in seconds).
  --minduration MINDURATION
                        Minimum allowed duration for note (in seconds).
                        Shorter notes will be removed.
  --jams                Also save output in JAMS format.


Non-python dependencies

Python dependencies

This program requires Python 2.7 (it has not been tested on Python 3 and will most likely crash).

All python dependencies (listed below) can be installed by calling pip install -r requirements.txt.

Known to work with the following module versions on python 2.7:

  • SoundFile==0.10.2
  • resampy==0.2.1
  • vamp==1.1.0
  • MIDIUtil==1.2.1
  • jams==0.3.3
  • numpy==1.16.2
  • scipy==1.2.1

How to contribute

If you would like to contribute a feature and/or bugfix to this repository, please follow the following steps:

  1. Create an issue describing the bug/feature
  2. I will reply on the issue thread to determine whether the feature can/should be added
  3. Discuss design/implementation details in the issue thread and reach consensus
  4. Once consensus is reached re: design/implementation, start a pull request
  5. Request code review once the pull requets is ready for review
  6. Fix requested changes to the pull request (if any)
  7. Pull request will then be merged

IMPORTANT: please be sure to always discuss a proposed feature/fix in an issue before creating a pull request.

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