#176 Log Frequency Scale for Spectrogram

[Lars Kindermann]

Dear Developers,

I´d love to have the option for a logartihmic (constant Q) frequency scale of the spectrogram plot, along with the option to specify max and also min frequencies for the plot.

This is essential for many sound analysis tasks as it maps equal musical intervalls to equal distances on the freq-scale.
See the attached example image for a comparison.

Relevant code may be found in Audacity which has this option built in.

Thanx, Lars

[Lars Kindermann]

Linear vs. Log Scale Example

[Joe Desbonnet]

I have a patch for that. It adds an -L option to spectrogram and renders frequency on a log scale. Figuring out how to contribute that now.

Details here: http://jdesbonnet.blogspot.ie/2014/02/sox-spectrogram-log-frequency-axis-and.html

Patch/code here: https://github.com/jdesbonnet/joe-desbonnet-blog/tree/master/projects/sox-log-spectrogram

[ianll]

Great work. I hope this gets accepted into the mainline, and that you get to fix the known issues you listed in your blog post.

Ian