Browsed by
Month: September 2017

SoX – An Introduction

SoX – An Introduction

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…

Read More Read More

Spectrograms with FFMpeg

Spectrograms with FFMpeg

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…

Read More Read More

Depthmapping with FFMpeg and OpenCV

Depthmapping with FFMpeg and OpenCV

Depthmaps are typically greyscale images that represent how far an object is by the degree of shade.  They can be white-near, black-near, or some other color scale such as ironbar.  Depthmaps are useful for creating renders or systems that have a distance sensing need. In this post I’ll be using footage that I shot using 2 Innovv cameras.  The rig was not precise, so I also post processed it to correct distortion and alignment issues.  The post processing topic was…

Read More Read More