I have mentioned my code in Java mode , can anyone suggest me how to convert this amplitude values to decibels.
import processing.sound.*;
Amplitude amp;
AudioIn in;
void setup() {
size(640, 360);
background(255);
// Create the Input stream
amp = new Amplitude(this);
in = new AudioIn(this, 0);
in.play();
amp.input(in);
}
void draw() {
println(amp.analyze());
}
The conversion formula for decibels is:
100 + 20./2.302585092994 * log(x), where x is the linear volume or RMS. It looks like analyze() gives you the RMS value so just replace that with x.
I hope that is what you’re looking for.
Yaa but not exactly, I am having a problem like when I use float it shows that it is unexpected.
Hi @hemangi_2810, Can you provide the code that is not working for you? I’m not able to reproduce that problem.
I used your code but changed the draw() method to:
void draw() {
println( 100 + 20./2.302585092994 * log(amp.analyze()) );
}
And it prints the dB values as expected. Was there another functionality you were looking for?
Yes it is working, thank you 
Hello,
Adding some references to the topic…
https://processing.org/reference/libraries/sound/Amplitude.html
The Description states that it returns RMS value.
log() \ Language (API) \ Processing 3+
Description and example of converting to log base-10
println(log(10)); will print 2.3025851 to the console
What is a decibel (dB)?
https://www.rapidtables.com/electric/decibel.html
You can use the Math class directly
// Using the Power quantities (See Wikipedia reference):
float P = 0.5; // Power measured
float Po = 1; // Using 1 as reference
// Using Math class directly
double dB1 = 10 * Math.log10(P/Po);
println(dB1);
// Using Processing helper function
float dB2 = 10 * log(P/Po)/log(10);
println(dB2);
The example code is for power levels and may need to be modified for field levels.
See the Wikipedia reference for above example:
https://en.wikipedia.org/wiki/Decibel
For the RMS values it will be factor of 20 instead of 10.
See the formulas in the Wikipedia reference (above) for Root-power (field) quantities.
:)