#include <SDL/SDL.h>
#include <stdio.h>
 
using namespace std;
 
void func_callback(void *unused, Uint8 *stream, int len) {
 
    for (int i=0;i<len;i++) {
        stream[i] = i;
    }

NSData *soundData = [NSData dataWithContentsOfURL:url];
AVAudioPlayer  *avPlayer = [[AVAudioPlayer alloc] initWithData:soundData error: nil];
[avPlayer play];