counting the number of frequency in wav file
4 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
faiz hazizi
am 24 Apr. 2018
Kommentiert: faiz hazizi
am 29 Apr. 2018
hi, i would like to count the number of frequency on my sample audio file. it is a recorded drum audio file which contain 8 beat of kick pedal in 7 seconds. so the problem is, how to make a simulation to count the number of kick pedal in this audio file (.wav)
here are my .wav file
[y,fs]=audioread('C:\Users\Faiz\Desktop\Kick.wav');
t=linspace(0,length(y)/fs,length(y));
plot (t,y)
7 Kommentare
Jan
am 26 Apr. 2018
@faiz hazizi: Remember that a diagram without labels does not explain anything. What do the two diagram represent?
The original signal has positive and negative values. You are not interested in the maximum value, but in the maximum amplitude. This can be positive or negative. Using abs helps to move all values to the positive side. If you have a single signal (mono sound), this is exactly the same as RMS: The mean of a scalar is the scalar, and Root of Squared value makes the sign positive. For a stereo signal, RMS considers both channels.
There is no "relationship" between RMS and findpeaks. The first one converts the signal to do what you want, the second one finds the peaks.
"your_signal" is the "y" in your code: The variable in which the audio signal is stored.
Akzeptierte Antwort
Jan
am 26 Apr. 2018
[y, fs] = audioread('C:\Users\Faiz\Desktop\Kick.wav');
yRMS = sqrt(sum(y .^ 2, 2)); % Root mean square, same as abs(y) for mono signal
[pk, loc] = findpeaks(yRMS, 'MinPeakHeight', std(yRMS));
Weitere Antworten (1)
Von Duesenberg
am 25 Apr. 2018
A possible workflow:
%compute the envelope of y (your signal)
%assuming it's mono, and adjust the second
%parameter of the envelope function with
%successive plots of myEnv
[myEnv, ~] = envelope(y, 3000, 'peak');
%apply findpeaks, and adjust 'MinPeakProminence'
%to your needs
[pk, loc] = findpeaks(myEnv, 'MinPeakProminence', .5);
%get the number of peaks
nbPk = length(pk);
6 Kommentare
Von Duesenberg
am 26 Apr. 2018
Bearbeitet: Von Duesenberg
am 26 Apr. 2018
If you do
size(y)
And the second output says 2, then your audio is stereo; if it says 1, your audio is mono.
Jan
am 26 Apr. 2018
@faiz: "Mono" means, that the sound has been recorded with 1 channel. "Stereo" uses 2 channels, and needs 2 microphones. Ask WikiPedia for details.
If a sound is recorded with 2 channels, the output of audioread must have two columns also. See: doc audioread.
Siehe auch
Kategorien
Mehr zu Get Started with Signal Processing Toolbox finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!