How can I create a waveform image of an MP3 in Linux?

Question

Given an MP3 I would like to extract the waveform from the file into an image (.png)

Is there a package that can do what I need ?

Answer 1

This is a standard function in SoX (command line tool for sound, Windows & Linux) Check the 'spectrogram' function on http://sox.sourceforge.net/sox.html

"The spectrogram is rendered in a Portable Network Graphic (PNG) file, and shows time in the X-axis, frequency in the Y-axis, and audio signal magnitude in the Z-axis. Z-axis values are represented by the colour (or optionally the intensity) of the pixels in the X-Y plane. If the audio signal contains multiple channels then these are shown from top to bottom starting from channel 1 (which is the left channel for stereo audio)."