I had the idea for this a long time ago, and wanted to make it to prove a point. This program is not intended for, nor should it be used for, copyright infringement and piracy. Nightcore is not, and has never been, fair use.

Installation

FFmpeg is a required dependency - see here for instructions on how to set it up!

With FFmpeg installed, you can use pip to install nightcore (although pipx is recommended when only installing the CLI)

pip install nightcore

Building from source

nightcore is built using Poetry.

$ git clone https://github.com/SeparateRecords/nightcore
$ poetry install
$ poetry build

CLI Usage

nightcore is predictable and ensures there is no unexpected behaviour. As nightcore relies on FFmpeg under the hood, any format supported by FFmpeg is supported by the CLI.

Speed/pitch

Speeding up a track is super easy. By default, it will increase the pitch by 1 tone.

$ nightcore music.mp3 > out.mp3

You can manually set the speed increase by passing a number after the file. Without specifying a type, the increase will be in semitones.

$ nightcore music.mp3 +3 > out.mp3

Types

You can change the type of speed increase by providing it after the number. At the moment, nightcore can take any of semitones, tones, octaves or percent.

$ nightcore music.mp3 +3 tones > out.mp3

When using percentages, 100 percent means no change, 150 percent is 1.5x speed, 80 percent is 0.8x speed, etc.

$ nightcore music.mp3 150 percent > out.mp3

Format & Codec

If file's format cannot be inferred from its extension, you can specify it manually with --format (-f).

$ nightcore --format ogg badly_named_file > out.mp3

The codec can be manually set using --codec (-c).

Output

If the output cannot be redirected, you can specify an output file with --output (-o). The format will be guessed from the extension.

$ nightcore music.mp3 --output out.mp3

To manually set the output format (useful if redirecting), use --output-format (-x).

$ nightcore music.mp3 --output-format ogg > music_nc.ogg

If this option is not provided, the output format will be guessed in this order, defaulting to MP3 if all fail:

1. Output option file extension (--output example.wav)
2. Explicit input file type (--format ogg)
3. Input file extension (music.ogg)

EQ

To compensate for a pitch increase, the output track will have a default +2db bass boost and -1db treble reduction applied. To disable this, pass in --no-eq. Note that if the speed is decreased, there will be no automatic EQ.

$ nightcore music.mp3 --no-eq > out.mp3

API Usage

The nightcore API is built using pydub, a high level audio processing library. It's worth reading a bit of its documentation (or at least the section on exporting), but you'll get by with only having read the examples below.

The API itself performs no equalization, unlike the CLI - see nightcore/cli.py for the implementation (search "parameters").

As the word nightcore is long, it's recommended to import the module as nc.

Quickstart

You can use any of Octaves, Tones, Semitones, or Percent to change speed. These are all subclasses of the base RelativeChange class.

Using the @ operator with one of the above classes is the most convenient way to nightcore a path-like object or AudioSegment.

import nightcore as nc

nc_audio = "tests/test.mp3" @ nc.Tones(1)

nc_audio.export("tests/test_nc.mp3")

Advanced Usage

nightcore(audio_or_path, amount, **kwargs) -> AudioSegment

The @ operator is shorthand for the nightcore function. The function only needs to be called manually if:

• You need to provide additional keyword arguments to AudioSegment.from_file
• The operator is less readable in context
• You need to use a function

There is also an equivalent async function in its own namespace (nightcore.aio).

import nightcore as nc

# Additional keyword args are passed to AudioSegment.from_file
audio = nc.nightcore("/tmp/badly_named_audio", nc.Semitones(2), format="ogg")

Contributing

Contributions, feedback, and feature requests are all welcome and greatly appreciated, no matter how small.

License

This project is licensed under the MIT license.