On 20/02/2015 15:28, Rivoire David wrote:
Yeah, but there is a link between this two topics, after having analysed the harmonics I would like to create a sequence of notes about it and automatically get chords that fit into it...
In general, this is not an "easy" task. I'm currently working (research) on the audio chord estimation (ACE) topic. For a "standard" song (polyphonic, poly-intrument) the accuracy is still far from perfect (~75% of accuracy on a given, limited, test-set).
However, for a single instrument, you can achieve good results with a simple template matching. You can't work directly on the FFT, but from the FFT you have to calculate a 12-dimensional mid-level descriptor (called Pitch Class Profile). Then you can train your chord templates using a specified instrument (i.e. if you want to estimate piano chords, you have to train your templates with your piano).
Cheers