Import Meyda and define a signal to test against
var Meyda = require('meyda');
We construct a signal that crosses the zero threshold 15 times. The signal is of a length that is a power of 2 - 32 - this is because Meyda requires input signals to be a power of two in order to optimize for the fast fourier transform that is required for most other feature extractors
var signal = (new Array(32).fill(0).map((element, index) => {
const remainder = index % 3;
if (remainder === 0) {
return 1;
} else if (remainder === 1) {
return 0;
}
return -1;
}));
Finally, we call the Zero Crossing Rate audio feature extractor on the signal we defined.
Meyda.extract('zcr', signal);
As we can see, it correctly counts 15 crosses of zero in the signal duration.
1 comment
- posted 5 years ago byHello, how do I extract this signal from an audio?
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