pyloudnorm

Flexible audio loudness meter in Python.

Implementation of ITU-R BS.1770-4.
Allows control over gating block size and frequency weighting filters for additional control.

For full details on the implementation see our paper with a summary in our AES presentation video.

Installation

You can install with pip as follows

pip install pyloudnorm

For the latest releases always install from the GitHub repo

pip install git+https://github.com/csteinmetz1/pyloudnorm

Usage

Find the loudness of an audio file

It's easy to measure the loudness of a wav file. Here we use PySoundFile to read a .wav file as an ndarray. ```python import soundfile as sf import pyloudnorm as pyln

data, rate = sf.read("test.wav") # load audio (with shape (samples, channels)) meter = pyln.Meter(rate) # create BS.1770 meter loudness = meter.integrated_loudness(data) # measure loudness ```

Loudness normalize and peak normalize audio files

Methods are included to normalize audio files to desired peak values or desired loudness. ```python import soundfile as sf import pyloudnorm as pyln

data, rate = sf.read("test.wav") # load audio

peak normalize audio to -1 dB

peaknormalizedaudio = pyln.normalize.peak(data, -1.0)

measure the loudness first

meter = pyln.Meter(rate) # create BS.1770 meter loudness = meter.integrated_loudness(data)

loudness normalize audio to -12 dB LUFS

loudnessnormalizedaudio = pyln.normalize.loudness(data, loudness, -12.0) ```

Advanced operation

A number of alternate weighting filters are available, as well as the ability to adjust the analysis block size. Examples are shown below. ```python import soundfile as sf import pyloudnorm as pyln from pyloudnorm import IIRfilter

data, rate = sf.read("test.wav") # load audio

block size

meter1 = pyln.Meter(rate) # 400ms block size meter2 = pyln.Meter(rate, block_size=0.200) # 200ms block size

filter classes

meter3 = pyln.Meter(rate) # BS.1770 meter meter4 = pyln.Meter(rate, filterclass="DeMan") # fully compliant filters
meter5 = pyln.Meter(rate, filterclass="Fenton/Lee 1") # low complexity improvement by Fenton and Lee meter6 = pyln.Meter(rate, filterclass="Fenton/Lee 2") # higher complexity improvement by Fenton and Lee meter7 = pyln.Meter(rate, filterclass="Dash et al.") # early modification option

create your own IIR filters

myhighpass = IIRfilter(0.0, 0.5, 20.0, rate, 'highpass') myhighshelf = IIRfilter(2.0, 0.7, 1525.0, rate, 'highshelf')

create a meter initialized without filters

meter8 = pyln.Meter(rate, filter_class="custom")

load your filters into the meter

meter8.filters = {'myhighpass' : myhighpass, 'myhighshelf' : myhigh_shelf}

## Dependancies
- **SciPy** ([https://www.scipy.org/](https://www.scipy.org/))
- **NumPy** ([http://www.numpy.org/](http://www.numpy.org/))


Citation
If you use pyloudnorm in your work please consider citing us.

@inproceedings{steinmetz2021pyloudnorm, title={pyloudnorm: {A} simple yet flexible loudness meter in Python}, author={Steinmetz, Christian J. and Reiss, Joshua D.}, booktitle={150th AES Convention} year={2021}} ```

References

Ian Dash, Luis Miranda, and Densil Cabrera, "Multichannel Loudness Listening Test," 124th International Convention of the Audio Engineering Society, May 2008

Pedro D. Pestana and Álvaro Barbosa, "Accuracy of ITU-R BS.1770 Algorithm in Evaluating Multitrack Material," 133rd International Convention of the Audio Engineering Society, October 2012

Pedro D. Pestana, Josh D. Reiss, and Álvaro Barbosa, "Loudness Measurement of Multitrack Audio Content Using Modifications of ITU-R BS.1770," 134th International Convention of the Audio Engineering Society, May 2013

Steven Fenton and Hyunkook Lee, "Alternative Weighting Filters for Multi-Track Program Loudness Measurement," 143rd International Convention of the Audio Engineering Society, October 2017

Brecht De Man, "Evaluation of Implementations of the EBU R128 Loudness Measurement," 145th International Convention of the Audio Engineering Society, October 2018.