Menu
I allready have FFT and pitch + absolute frequency calculated in real-time from input of microphone. Now I want to calculate the timbre.
I saw Mel Frequency Cepstrum Coefficients - MFCCs but I didn't understand it very well. Can someone give me some tips on this..
721
MFCCs are commonly used as features in speech recognition systems, such as the systems which can automatically recognize numbers spoken into a telephone. MFCCs are also increasingly finding uses in music information retrieval applications such as genre classification, audio similarity measures, etc.
Cepstrum of speech segment. The most visually prominent feature in this cepstrum is the peak near quefrency 7 ms. It corresponds to a fundamental frequency of 1000/(7 s) = 143 Hz.
The MFCC feature extraction technique basically includes windowing the signal, applying the DFT, taking the log of the magnitude, and then warping the frequencies on a Mel scale, followed by applying the inverse DCT. The detailed description of various steps involved in the MFCC feature extraction is explained below.
MFCCs combine consideration of aspects of human hearing (logarithmic frequency perception, the mel scale) and physics of musical instruments (these systems often have well defined overtones that are harmonic -- which is why the MFCCs use the FFT of the FFT), to give a simplified representation of the timbre of an instrument (where the fundamental frequency and loudness are factored out).
One could write endless pages on this topic, and there are many available on the web, so a more specific question that explains clearly what you want to know would be helpful. The algorithm for calculating MFCCs is listed at the top of the wikipedia page.
71
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
