CloudACM – Page 37 – Autonomous Computational Machines

Sox Band-Pass and Band-Reject Filtering

October 2, 2017 Patrick Gilfeather

SoX provides many filters to process audio data. In this post I’ll be covering how to apply pass or reject filtering of frequency bands, commonly referred to as band-pass or band-reject. This filter will take a frequency or a range of frequencies and either remove them from an audio file or remove all other frequencies while keeping only them. I’ll cover 5 filters available in SoX that do this type of audio processing. Here is some information about each of…

SoX – An Introduction

September 25, 2017 Patrick Gilfeather

SoX, short for Sound eXchange, is a command line utility that can convert audio data into other formats. It can also apply various effects, play, record, mix, and filter the audio data. Refer to the development website, http://sox.sourceforge.net/. In a previous post I used it to create a spectrogram of an audio file using this command. sox audio-in.wav -n spectrogram Lets start with basic play operation. SoX can play audio data through the command line using the play command, here…

Spectrograms with FFMpeg

September 18, 2017 Patrick Gilfeather

In this post I’ll be covering how to create image files that represent the sound levels and frequencies of a media file. These images are known as spectrograms. They provide a way to visually locate moments in time. This can be useful for a number of reasons. FFMpeg has a feature that lets us create spectrograms with the showspectrumpic filter. Details about this filter can be found here, https://ffmpeg.org/ffmpeg-filters.html#showspectrumpic. You can also get information about the filter by typing in…