Question

我必须实现一个iphone应用程序，它会在你开始说话时录制用户的声音，并改变录制声音的音高并播放。我能够在AVAudiorecorder的帮助下录制声音检测音频，并使用Dirac库我改变了录制声音的音高。这种方法的问题是输出声音足够嘈杂。我得到了使用SoundEngine的响应，但我没有得到实现它的方法。任何人都可以解释一下其他任何实现方法吗？

my code//
        -(void)initialSetup
    { 
        count=0; 
        silenceTime=0;

    //[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error: nil];
    recordSetting = [[NSMutableDictionary alloc] init];
    [recordSetting setValue:[NSNumber numberWithInt:kAudioFormatAppleLossless] forKey:AVFormatIDKey];
    [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey]; 
    [recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
    recordedTmpFile = [NSURL fileURLWithPath:[NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat: @"%.0f.%@",[NSDate timeIntervalSinceReferenceDate]*1000.0,                  @"caf"]]];
    recorder = [[ AVAudioRecorder alloc] initWithURL:recordedTmpFile settings:recordSetting error:&error];
    //recorder = [[ AVAudioRecorder alloc] init];
    [recorder setDelegate:self];
    [recorder updateMeters];
    [recorder prepareToRecord];
    //[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayAndRecord error: nil];
    //In Order To Move Sound To The Speaker
    //UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    //AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof(audioRouteOverride),&audioRouteOverride);

    NSArray *dirPaths;
    NSString *docsDir;
    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = [dirPaths objectAtIndex:0];
    NSString *soundFilePath = [docsDir stringByAppendingPathComponent:@"audio.caf"];
    recordedTmpFile1 =  [NSURL fileURLWithPath:soundFilePath];

    recordSetting1 =   [[NSMutableDictionary alloc] init];
    recordSetting1 =   [NSDictionary dictionaryWithObjectsAndKeys:
                        [NSNumber numberWithInt:AVAudioQualityMin],AVEncoderAudioQualityKey,
                        //[NSNumber numberWithInt:kAudioFormatAppleIMA4],AVFormatIDKey,
                        [NSNumber numberWithInt:16], 
                        AVEncoderBitRateKey,
                        [NSNumber numberWithInt: 2], 
                        AVNumberOfChannelsKey,
                        [NSNumber numberWithFloat:44100.0], 
                        AVSampleRateKey,nil];
    recorder1 = [[AVAudioRecorder alloc] initWithURL:recordedTmpFile1 settings:recordSetting1 error:&error];
    [recorder1 prepareToRecord];
    [recorder1 setDelegate:self];
    if(recorder) 
    {
        recorder.meteringEnabled = YES;
        [recorder record];
        double val=[recorder peakPowerForChannel:0];
        NSLog(@"The Very First Value Of The Recorder Is=%f",val);
        levelTimer = [NSTimer scheduledTimerWithTimeInterval:0.4 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
    }
    else
    {
        NSLog(@"error in initilising of the recorder=%@",[error localizedDescription]);
    }
}


-(void)levelTimerCallback:(NSTimer *)timer                      
{ 
    [recorder updateMeters];
    const double ALPHA = 0.05;
    //NOISE FILERATION ALGORITHMS
    double peakPowerForChannel = pow(10,(0.05 *[recorder peakPowerForChannel:0]));
    double audioMonitorResults1 = ALPHA * peakPowerForChannel + (1.0 - ALPHA) * audioMonitorResults1;
    double audioMonitorResults;
    audioMonitorResults= [recorder peakPowerForChannel:0];
    NSLog(@"This time only  frequency is==>%f",audioMonitorResults1);
    //if (audioMonitorResults1 >0.020)
    if(audioMonitorResults1 > .05)//the value of audioMonitorResults may be equal to -10 for device
    {

        [recorder1 updateMeters];
        recorder1.meteringEnabled=YES;
        //recorder.meteringEnabled=YES;
        [recorder1 record];
        NSLog(@"SOUND IS DETECTED");
        NSLog(@"%f",[recorder1 peakPowerForChannel:0]);
        NSLog(@"Recording is going on");
        count=1;
        silenceTime=0;

    }
    else
    {

        NSLog(@"NO SOUND IS DETECTED");
        silenceTime=silenceTime+0.3;
        if(count==1 && silenceTime>1)
        { 

            [levelTimer invalidate];
            [recorder1 stop];

        }

    }

}
- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag
{
    NSLog(@"Recorder stop delegate is processing");
    if(flag)
    {
        NSLog(@"Player has finished successfully");
        [self playRecording];
    }
    else
    { 
        NSLog(@"problem in recording.......not recorded");
    }
}

Answer 1

如何检测声音？
我在教程的帮助下解决了我的第一个问题。这里有链接，链接：http://mobileorchard.com/tutorial-detecting-when-a-user-blows-into-the-mic/
在这里，我们可以很容易地理解在检测到某些噪音时录制的声音。
如何改变录制声音的音高并进行播放我在改变声音音高时面临的第二个问题。由于我们只能在AVAudioRecorder的帮助下录制声音，因此我们不能改变音高为此，我使用了外部库 DIRAC 。 Here is the link for the Dirac library.
这为应用程序提供了关于dirac库实现的一些示例项目（适用于移动应用程序以及桌面应用程序）。

我发现通过使用Dirac实现Cocoas2D，Cocos Denshion解决此问题的另一种方法。因为上述问题与我的应用程序不兼容。 Here is the link for implementing this（关于改变音高并播放录制声音的示例项目）。

我发现another link与录音有关。

Answer 2

实际上有一个更简单的解决方案。使用音频播放器的速率功能。它的范围在0.1f - 2.0f之间，其中较高的数字意味着更快更尖锐的音调，更低的数字意味着缓慢的拖出声音（深沉的声音）

player = [[AVAudioPlayer alloc] initWithContentsOfURL:
                  [NSURL fileURLWithPath:path] error:&err];
        player.volume = 0.4f;
        player.enableRate=YES;
        [player prepareToPlay];
        [player setNumberOfLoops:0];
        player.rate=2.0f;
        [player play];

录制声音并以改变的音高播放

2 个答案: