b2btest audio - audio data support for back-to-back tests

This package adds audio file support to b2btest. b2btest is a tool to automate tests that compare results to some previous ones, and this plugin, is helpful to compare audiofiles in a sensible way.

See b2btest README for a deeper discussion on why you should avoid back-to-back testing, although sometimes it is the lesser evil way to proceed.

This plugin handles audiofiles specially in several ways:

• Instead of doing a text or byte difference, it interprets the audio contents and compares them sample by sample.
• It considers two outputs to be different if:
  • Metadata differs
  • Sample-by-sample differs relative to the audio level
• In the case of differences, it generates a diff audio by substracting both waves sample by sample.

By means of python-wavefile, it supports floating point samples, and multichannel waves.

How to install

Just use:

$ pip install b2btest_audio

Dependencies

This plugin requires the wavefile module, which in turn requires having libsndfile library installed in your system.

Back2Back testing of cli programs

When you are testing back-to-back the output of a command line, you define a yaml file like this (name it b2bcases.yaml).

#!/usr/bin/env back2back 

datapath: "b2bdata" # Point it to the directory containing your reference data
testcases:

  Generate1KHzSine:
    command: sox -n /tmp/sine.wav synth 1.0 sine  1000.0
    outputs:
    - /tmp/sine.wav

Ouputs with supported audio file extension will be recognize and this plugin diff will be used for them.

See [b2btest] documentation on how to use this file.

Command line tool

The package also provides a diffaudio CLI tool to generate the audio difference