iPhone麦克风级别:代码在一个项目中工作,而不是在另一个项目中

iPhone麦克风级别:代码在一个项目中工作,而不是在另一个项目中,iphone,microphone,avaudiorecorder,Iphone,Microphone,Avaudiorecorder,这个代码对我来说很好用。我将其设置为吐出lowPAssResult的值。在电话上运行它,果然如预期 2011-07-04 14:28:08.672微吹[280:707]检测到微吹:0.036449 …等等,如果我向它吹气,它的值会上升。一切都好 但当我把它放在我自己的项目框架中时,它就不起作用了。我把这段代码放在我的init函数中 //Set up the mic stuff NSURL *url = [NSURL fileURLWithPath:@"/dev/null"]; NSDictio

这个代码对我来说很好用。我将其设置为吐出lowPAssResult的值。在电话上运行它,果然如预期

2011-07-04 14:28:08.672微吹[280:707]检测到微吹:0.036449 …等等,如果我向它吹气,它的值会上升。一切都好

但当我把它放在我自己的项目框架中时,它就不起作用了。我把这段代码放在我的init函数中

//Set up the mic stuff
NSURL *url = [NSURL fileURLWithPath:@"/dev/null"];

NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
                          [NSNumber numberWithFloat: 44100.0],                 AVSampleRateKey,
                          [NSNumber numberWithInt: kAudioFormatAppleLossless], AVFormatIDKey,
                          [NSNumber numberWithInt: 1],                         AVNumberOfChannelsKey,
                          [NSNumber numberWithInt: AVAudioQualityMax],         AVEncoderAudioQualityKey,
                          nil];

NSError *error;

recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&error];

if (recorder) 
{
    [recorder prepareToRecord];
    [recorder record];
    recorder.meteringEnabled = YES;        
    levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.03 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
} 
并添加了这个回调

- (void)levelTimerCallback:(NSTimer *)timer {
[recorder updateMeters];

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

    NSLog(@"Mic blow detected -  peakPowerForChannel : %f, lowPassResults: %f",peakPowerForChannel,lowPassResults);
}
输出如下所示

2011-07-04 14:30:32.974分钟摄像头[290:707]检测到话筒吹出:0.000001 反复地每帧

不管我吹多少次。请帮忙,我相信这一定很简单