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我想知道这个应用程序RoboStrobe如何检测节拍。我正在使用“AVAudioRecorder”来收听麦克风并获取声级计，但我不知道计算电平和节拍并触发我的方法的正确方法。

这是我现在要做的：

调用更新方法：

levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.05 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];

还有我的更新方法

-(void)update
{
[recorder updateMeters];


const double ALPHA = 0.05;
double peakPowerForChannel = pow(10, (0.05 * [recorder peakPowerForChannel:0]));
lowPassResults = ALPHA * peakPowerForChannel + (1.0 - ALPHA) * lowPassResults;

double scale = lowPassResults * 5;
NSLog(@"Result = %f",scale);
if (scale>4.5) {
    [[UIScreen mainScreen] setBrightness:1.0];
    NSLog(@"HEAVY Scale = %f",scale);
    [self turnTorchOn:YES];
    [self performSelector:@selector(off) withObject:Nil afterDelay:0.4];
}

else
{
    [self turnTorchOn:NO];
    [[UIScreen mainScreen] setBrightness:0.1];
}
}
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1 回答 1

2

Beat detection requires non-trivial audio processing (comb filter, onset detection etc.). You'll want to use a library for it. Possible candidates are:

But there are many more out there. And there are many related questions on StackOverflow.

于 2013-10-05T14:32:29.417 回答