audiolab

A Python library for audio processing built on top of bv (bindings for FFmpeg). audiolab provides a simple and efficient interface for loading, processing, and saving audio files.

Features

• Load audio files in various formats (WAV, MP3, FLAC, AAC, etc.)
• Save audio files in different container formats
• Support for audio streaming and real-time processing
• Integration with popular audio libraries like Lhotse
• Command-line interface for audio file inspection
• Support for audio transformations and filtering

Installation

pip install audiolab

Quick Start

Load an audio file

import audiolab

# Load an audio file
audio, rate = audiolab.load_audio("audio.wav")
print(f"Sample rate: {rate} Hz")
print(f"Audio shape: {audio.shape}")

Save an audio file

import audiolab
import numpy as np

# Create a simple sine wave
rate = 44100
duration = 5
t = np.linspace(0, duration, rate * duration)
audio = np.sin(2 * np.pi * 440 * t)

# Save as WAV file
audiolab.save_audio("tone.wav", audio, rate)

Get audio file information

import audiolab

# Get information about an audio file
info = audiolab.info("audio.wav")
print(info)

Command-line usage

# Get information about an audio file
audi audio.wav

# Show only specific information
audi -r -c audio.wav  # Show sample rate and channels only
audi -d audio.wav     # Show duration in hours, minutes and seconds
audi -D audio.wav     # Show duration in seconds

CLI Options

• -S, --stream-id INTEGER The index of the stream to load (default: 0)
• -f, --force-decoding Force decoding the audio file to get the duration
• -t, --show-file-type Show detected file-type
• -r, --show-sample-rate Show sample-rate
• -c, --show-channels Show number of channels
• -s, --show-samples Show number of samples (N/A if unavailable)
• -d, --show-duration-hms Show duration in hours, minutes and seconds (N/A if unavailable)
• -D, --show-duration-seconds Show duration in seconds (N/A if unavailable)
• -b, --show-bits-per-sample Show number of bits per sample (N/A if not applicable)
• -B, --show-bitrate Show the bitrate averaged over the whole file (N/A if unavailable)
• -p, --show-precision Show estimated sample precision in bits
• -e, --show-encoding Show the name of the audio encoding
• -a, --show-comments Show file comments (annotations) if available
• --help Show this message and exit

If no specific options are selected, all information will be displayed by default.

API Overview

Core Functions

• load_audio(): Load audio from file or stream
• save_audio(): Save audio to file or stream
• info(): Get information about an audio file
• encode(): Transform audio to PCM bytestring

Classes

• Reader: Read audio files with advanced options
• StreamReader: Read audio streams
• Writer: Write audio files with custom parameters

Advanced Usage

Apply filters during loading

import audiolab
from audiolab.av import aformat

# Load audio and convert to mono with specific sample rate
filters = [aformat(rate=16000, to_mono=True)]
audio, rate = audiolab.load_audio("audio.wav", filters=filters)

Stream processing

import audiolab

# Process audio in chunks
reader = audiolab.Reader("audio.wav", frame_size=1024)
for chunk, rate in reader:
    print(chunk.shape)

License

Apache License 2.0