有一个观点来获得ios 7中的麦克风音量？
@H_403_2@NSURL *url = [NSURL fileURLWithPath:@"/dev/null"];
NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat: 44100.0],AVSampleRateKey,[NSNumber numberWithInt: kAudioFormatAppleLossless],AVFormatIDKey,[NSNumber numberWithInt: 0],AVNumberOfChannelsKey,[NSNumber numberWithInt: AVAudioQualityMax],AVEncoderAudioQualityKey,nil];
NSError *error;
recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&error];
if (recorder) {
//recorder.delegate = self;
[recorder prepareToRecord];
recorder.meteringEnabled = TRUE;
[recorder record];
levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.1 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
} else {
NSLog(@"");// mic error message
}
- (void)levelTimerCallback:(NSTimer *)timer {
[recorder updateMeters];
const double ALPHA = 0.05;
double peakPowerForChannel = pow(10,(ALPHA * [recorder averagePowerForChannel:0]));
db = 20* log10(peakPowerForChannel);
db += taraturaDb;
db = db < 0 ? 0 : db;
lowPassResults = ALPHA * peakPowerForChannel + (1.0 - ALPHA) * lowPassResults;
if (lowPassResults < 0.95) {
NSLog(@"%f",db);
}
这在iOS6中有效,在iOS 7中不起作用
谢谢
