I would like to ask on what approaches could one attempt to generate a colored waveform out of an audio file. Below are two examples of waveform coloring by commercial products along an audio sample of that music at this position:
Audio sample at this position:
By looking at the output, one can infer the following:
- low frequency content is colored in red
- mid frequency content is colored in green
- high frequency content is colored in blue
Obviously, this is a very simplistic analysis of the situation and doesn't really tell how it's been done.
What kind of algorithm is at work under the hood to produce such colored waveforms?
I have asked a similar question a while ago, now I feel it's time to ask it again for these reasons:
- question has been asked 6 years ago!
- the EchoNest web service used for detecting audio features has closed shop
- couldn't really make good use of @pichenettes answer by lack of knowledge
- still little public information on the web about this subject
- there might be fresh minds that can suggest interesting approaches
(let me know how this question can be improved to be complementary to the one previously asked)