trustytrojan/speedup.py

A simple Python script to speed up your music/audio

speedup.py

A simple Python module to speed up (or slow down) audio. It also comes with a commandline interface and a Flask server.

Installation

To install speedup.py run:

pip install speedup.py

The speedup.py module has optional dependencies required for the CLI and API modules. Run one of the three lines below to:

pip install speedup.py[cli]			# Only install CLI dependencies
pip install speecup.py[server]		# Only install server dependencies
pip install speedup.py[cli,server]	# Install dependencies for both

Usage

Assuming you have soundfile for reading in audio files, speeding up audio from a file called audio.mp3 by a factor of 1.5 takes four lines of Python code:

from speedup import speedup
import soundfile as sf
audio, samplerate = sf.read("audio.mp3")
spedup_audio = speedup(audio, 1.5)

The speedup function returns the sped up audio as a NumPy array, which you can then save to a file like so:

sf.write("spedup-audio.mp3", spedup_audio, samplerate)

CLI usage

The CLI abstracts everything in the previous section away.

To speed up audio.mp3 by a factor of 1.5, run:

speedup audio.mp3 1.5

Despite the project's name, multipliers below 1 work as well. The audio will be slowed down in this case:

speedup audio.mp3 0.75

In this case, the sped up audio is saved to audio-1.5x.mp3 by default. You can specify the output file using --output-file:

speedup audio.mp3 1.5 --output-file spedup.mp3

Since the resample operation takes some time, the --play option lets you hear your spedup audio without resampling:

speedup audio.mp3 1.5 --play

Using --play prevents saving the audio to a file, since the exact same file would be created, except the sample rate would be multiplied. This is because compressed audio formats (especially MPEG-3) don't support custom sample rates.

The --output-file and --play options are mutually exclusive.

Running the Flask server

You can run the Flask development server with:

python -m speedup.api

For production environments however, you should use a WSGI server like gunicorn:

pip install gunicorn
gunicorn -w 4 speedup.api:app

Building

To build the Python package, run the below commands in your terminal:

git clone https://github.com/trustytrojan/speedup.py
cd speedup.py
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python -m build