unmixer 1.0.0

Create and explore isolated tracks from music files

unmixer - create and explore isolated tracks from music files

unmixer is a graphical utility and Python package for creating isolated tracks (drums, bass, vocals, etc.) from music files.

unmixer is a frontend for demucs, an excellent command-line utility for music source separation from the Meta Research team. The creation of isolated tracks is handled entirely by demucs; unmixer provides a graphical interface for viewing, playing, and exporting the isolated tracks in any combination.

Installation

The easiest way to install the package is to download it from PyPI using pip. Note that unmixer depends on Python 3.11 or newer; please ensure that you have a recent version of Python installed before proceeding.

Run the following command in a shell (Linux or macOS is assumed):

$ pip install unmixer

The package does depend on a few external Python packages available on PyPI. If you wish to sandbox your installation inside a virtual environment, you may choose to use virtualenvwrapper or a similar utility to do so.

When successfully installed, a program called unmixer will be placed on your PATH. See the Usage section below for details about how to use this program.

Dependencies

• The utility expects ffmpeg to be installed for mixing isolated tracks. See the project's Downloads page for instructions on downloading and installing ffmpeg.

Usage

The unmixer program is a graphical utility for exploring isolated tracks extracted from a music file.

At any time, you can use the -h or --help flags to see a summary of options that the program accepts.

$ unmixer -h
usage: unmixer [-h] [-o OUTPUT] [-g | -p] [music_file_or_track_dir]

create and explore isolated tracks from music files

positional arguments:
  music_file_or_track_dir
                        path to the file to unmix, or path to a directory containing isolated tracks

options:
-h, --help            show this help message and exit
-o OUTPUT, --output OUTPUT, --output-dir OUTPUT
                      path to the directory for output isolated tracks (default: ~/unmixer)
-g, --guitar          show "Guitar" track instead of "Other"
-p, --piano           show "Piano" track instead of "Other"

Creating Isolated Tracks

To create isolated tracks for a specific song, pass the path to the song to unmixer. For example:

$ unmixer /path/to/Limelight.mp3

When invoked with no arguments, unmixer will open a window containing a button labeled Choose... (see the screenshot below).

Click the Choose... button and select a music file that you want to create isolated tracks from. The interface will change to reflect that the song is being processed (see the screenshot below).

Please be patient during the process of creating the isolated tracks, as it will take some time to complete! It typically takes about as long as the source song itself (or a bit longer) to create the isolated tracks for a song. For example, if a song is 5 minutes long, it will likely take roughly 5 minutes to create isolated tracks for that song.

NOTE: Although unmixer does not display a progress bar in its graphical interface showing the status of processing the song, the progress will be shown in the process's standard output (assuming the standard output is not redirected to a file). Check the shell or terminal from which you launched the unmixer UI to get a better approximation of how long it will take to process the song. A visual progress bar may be added in a future version.

Although it may be possible to speed up the process by adjusting the flags passed to demucs, the current implementation tends to favor producing higher quality isolated tracks at the expense of taking a bit longer. A future version of unmixer may allow customizing the quality, output format, machine learning model, or other settings that can be configured by demucs; the current version does not allow any such customization.

Output Tracks

The following isolated tracks are created by default:

• bass.wav
• drums.wav
• other.wav
• vocals.wav

These are the sources that are supported by demucs; unfortunately, there is currently no specific source available for guitar, piano, or any others besides bass, drums, and vocals. Any part of the song's audio that is not identified as bass, drums, or vocals will be found in the other.wav file.

Customizing the "Other" Track Name

In some cases, the isolated track other.wav may contain primarily a single instrument, such as a guitar or piano. In these cases, it may be useful for the resulting output track to have a corresponding name such as guitar.wav or piano.wav instead of the default other.wav.

To change the name of the "other" track to guitar.wav, the -g/--guitar flag may be passed to unmixer. Similarly, to change the name of the "other" track to piano.wav, the -p/--piano flag may be passed to unmixer instead. (It is an error to pass both -g and -p at the same time.) It is not currently possible to customize the name of the "other" track to be any arbitrary name, although this feature may be added in a future version.

Output Directory

By default, unmixer creates isolated tracks in subdirectories of the directory ~/unmixer. Each song's isolated tracks will be placed in a new subdirectory of the output directory named based on the song's filename. For example, isolated tracks for a song named Subdivisions.mp3 would be placed in the directory ~/unmixer/Subdivisions by default (note that the subdirectory does not include the .mp3 file extension).

NOTE: Creating isolated tracks for multiple songs with the same filename will result in any previous songs' isolated tracks being overwritten! If you need to process multiple distinct songs with the same filename, be sure to rename the created directories (or rename the song files themselves) to avoid conflicts!

Use the -o/--output/--output-dir flag to customize the output directory for isolated tracks created by unmixer. A subdirectory of this directory will be created for the isolated tracks, as described above.

Exploring Isolated Tracks

To explore isolated tracks located in a specific directory, pass the path to the directory to unmixer. For example:

$ unmixer ~/unmixer/YYZ

NOTE: If you used unmixer to create isolated tracks for a song, the Track Explorer window will open automatically when the song is finished processing. (Again...please be patient!)

The Track Explorer window displays the name of the song at the top, a set of playback controls at the bottom, and a waveform and a set of controls for each isolated track found in the input directory (see the screenshot below).

Playback Controls

Use the Play/Pause button found in the playback controls at the bottom of the Track Explorer to control playback of the currently selected track(s). Click the Restart button to start playback at the beginning of the song.

When the song is playing, you can drag the triangular playhead (displayed above the very topmost track, with a white line extending down over all of the waveforms) to skip to a specific part of the song. Dragging the playhead while the song is paused is not currently supported.

Track Controls

Each track has its own Mute button and Solo button displayed to the left of the track's waveform. Use a track's Mute button to remove that track from the mix you hear when playing the song. Inversely, use a track's Solo button to hear only that track when playing the song. As the name implies, only one track may have the Solo button active at a time. A track may not be both soloed and muted at the same time; soloing a muted track will unmute the track automatically. Playback will pause automatically if all tracks are muted at the same time.

Exporting a Custom Mix

Use the Export... button found in the playback controls at the bottom of the Track Explorer to export the currently selected (i.e., unmuted) tracks as a new file. A dialog box will open, allowing you to select a destination for the file and click Save. For example, to create an instrumental mix of a song, mute the Vocals track and export the remaining tracks as a new mix.

NOTE: Exporting is disabled when only a single track is selected, since that single track is already a self-contained file that does not need to be re-exported. Similarly, exporting is also disabled when all tracks are selected, since the resulting mix is the same as the original song file that produced the isolated tracks in the first place.

If you export custom mixes in the same directory where the isolated tracks are located, the custom mixes will also be loaded if you reopen the same directory using unmixer in the future. If you want to avoid this, save any custom mixes to a different directory, such as a remixes subdirectory of the directory where the isolated tracks are located.

Customizing the "Other" Track Name

In the same way as when creating isolated tracks (see above), the -g/--guitar flag may be passed to unmixer to change the displayed name of the Other track (if present) to Guitar. Similarly, to change the name of the Other track to Piano, the -p/--piano flag may be passed to unmixer instead. (It is an error to pass both -g and -p at the same time.) It is not currently possible to customize the name of the Other track to be any arbitrary name, although this feature may be added in a future version.