np3 0.2

Fast library to load MP3 into NumPY arrays

NP3

A fast python library to load mp3 data into NumPy arrays.

It is based on lieff's minimp3

Installation

pip install np3

Usage

import np3

mp3 = np3.MP3(path="/my/mp3/file")

# or

with open("/path/to/file.mp3") as mp3_fh:
    mp3 = np3.MP3(file=mp3_fh)

# or

data: bytes = obtain_mp3_data()
mp3 = np3.MP3(data=data)

print(f"Channels: {mp3.channels}")
print(f"Sampling rate: {mp3.hz} Hz")

length = len(mp3.samples[0]) / mp3.hz
print(f"Length: {length:.1f} seconds")

Threaded performance

GIL is released before decoding starts. On multi core machines this brings additional performance when decoding in separate threads. While decoding a single file does not parallelise, other python threads can continue working while the file is being processed. Where multiple files need decoding this performance gain becomes particularly significant.

from concurrent.futures import ThreadPoolExecutor

files = ["/path/to/file1.mp3", "/path/to/file2.mp3", ...]

with ThreadPoolExecutor() as executor:
    mp3s = executor.map(
        lambda p: np3.MP3(path=p),
        files,
    )