SndObj: Realtime audio input with SndCoreAudio

extend
1

Hey guys. I’m rather new to C++ programming, and I’m having a little trouble. I’m trying to generate some realtime graphics with SndObj. I tried working it out with ofxSndObj, but I couldn’t figure out how to connect startSystemInOut to the FFT function. So I’ve tried using SndObj directly.

testApp.cpp

  
#include "testApp.h"  
#include "stdio.h"  
  
  
//--------------------------------------------------------------  
void testApp::setup(){  
	  
	ofSetWindowTitle("template project");  
	ofSetFrameRate(60);  
	  
	audio.SetInput(&io, 1);  
	  
	window.SetParam(2500);  
	analysis.SetWindow(&window);  
	analysis.SetInput(&audio);  
	  
}  
  
//--------------------------------------------------------------  
void testApp::update(){  
	cout << "UPDATING...\n\n";  
	  
	io.Read();  
	audio.DoProcess();  
	analysis.DoProcess();  
	  
	cout	<< "SndIO:\t"	<< io.ErrorMessage()			<< "\n"  
			<< "SndIn:\t"	<< audio.ErrorMessage()	<< "\n"  
			<< "FFT:\t"		<< analysis.ErrorMessage()		<< "\n";  
	  
	int i = 0;  
	int len = analysis.GetFFTSize();  
	cout << "FFT length:\t" << len << "\n\n";  
	cout << "Analising:\t";  
	while(i < len) {  
		fft[i] = analysis.Output(i);  
		i++;  
		cout << fft[i] << ", ";  
	}  
}  
  
//--------------------------------------------------------------  
void testApp::draw(){  
	ofNoFill();  
	int i;  
	for (i = DEF_FFTSIZE; i > 0 ; i--) {  
		ofCircle(300, 300, fft[i]/(i*2));  
	}  
}

testApp.h

  
#ifndef _TEST_APP  
#define _TEST_APP  
  
#define MACOSX  
  
  
#include "ofMain.h"  
#include "ofxSndObj.h"  
#include "AudioDefs.h"  
  
class testApp : public ofBaseApp{  
	  
public:  
	  
	void setup();  
	void update();  
	void draw();  
	  
	SndCoreAudio io;  
	SndIn audio;  
	HammingTable window;  
	  
	FFT analysis;  
	float fft[1024];  
	  
	  
};  
  
#endif

Program outputs this:

UPDATING…

SndIO: No error

SndIn: No error.
FFT: No error

FFT length: 1024

Analising: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0, -0, 0,

There are no errors when it compiles, but nothing happens when the program runs. I couldn’t find a pre-built version of SndObj, so I’m just using it through ofxSndObj. After stumbling around google, I tried building the library on my own, but I really couldn’t figure it out. I’m using XCode on Snow Leopard.

I feel relatively stupid right now - could someone help me? I’ve tried my best on google, as I’m sure somebody’s done this before, but I can’t find anything that helps. :frowning: I’ve got a copy of Programming Interactivity (great book) but that hasn’t shed any light on my particular problem.

2

For realtime fft analysis on input channels you should check out the ofxFft extension. Here is a topic about it: http://forum.openframeworks.cc/t/ofxfft:-fftw-±kiss-fft-wrapper/2184/0
Dont forget to also install the KISS library for this. Works quite well for me (although I still have to figure out whats the best way to get a logarithmic scale).

Good luck. :slight_smile:

3

Yeah, I posted on that one. Maybe I might have learned enough by now to take another look at it. Thanks for reminding me!

4

Ah, I see… Yeah, I also don’t understand it fully yet, but slowly Im learning it. :slight_smile: