Making sound spectrum images from command line

Question

Most of the audio editors are able to show us different kinds of audio analysis like this:

• Wave form (whole file);
• spectral frequency (whole file);
• spectrum analysis (for a slice).

The generated images can be saved one way or another.

Is there a command line alternative to do this?

Windows 7. A multi-OS solution is preferred.

Answer 1

One of three tasks could be performed with SoX:

sox file.wav -n spectrogram

Answer 2

You can use ffmpeg to create spectrogram

ffmpeg -i inputfile.mp3 -lavfi showspectrumpic=s=800x400:mode=separate spectrogram.png

Filter documentation: https://ffmpeg.org/ffmpeg-filters.html#showspectrumpic

Answer 3

Since I couldn't find any windows examples, I've created a batch file you might find useful for automating all flac audio files in a directory, or which ever extension you choose to run, and creating a spectrogram for it (just change the (".*.flac") to (".*.extension") if you want them for different audio files) here:

FOR %%F IN (".\*.flac") DO sox.exe "%%F" -n spectrogram -p 2 -S 5 -y 240 -c "%%~NXF" -o "%%~NF.png"

Create a text file and put that code in it and save it as filename.bat, then run it with the files you choose in the sox directory, unless specified in another place. You can modify the colors as you see fit with -p 1 to 6.

Answer 4

I've just released specky which can do this for you as well.

pip install specky

specky-show my.mp3

Answer 5

For #3, Amplitude-Frequency plots, also called Bode plots,

• the libre software Audacity produces these under the name "Plot Spectrum..."
• a github project called WaveSpecter aims to tackle this from the command line.

Answer 6

Imagemagick would be the solution, but the screen capture does not seem to work in Windows (it's looking for an X server).

Refer to the answers to this similar question here for other options.