ios - AVAudio 的最佳麦克风录音设置是什么？

所以我有当前的代码:

- (void)viewDidLoad
{
    [super viewDidLoad];
    //for recording audio
    _stopButton.enabled = NO;
    _playButton.hidden = true;

    NSArray *dirPaths;
    NSString *docsDir;

    dirPaths = NSSearchPathForDirectoriesInDomains(
                                                   NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = dirPaths[0];

    NSString *soundFilePath = [docsDir
                               stringByAppendingPathComponent"recording.caf"];

    NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

    NSDictionary *recordSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithInt:kAudioFormatMPEG4AAC], AVFormatIDKey,
                                    [NSNumber numberWithFloat:44100.0], AVSampleRateKey,
                                    [NSNumber numberWithInt:1], AVNumberOfChannelsKey,
                                    [NSNumber numberWithInt:AVAudioQualityHigh], AVSampleRateConverterAudioQualityKey,
                                    [NSNumber numberWithInt:128000], AVEncoderBitRateKey,
                                    [NSNumber numberWithInt:16], AVEncoderBitDepthHintKey,
                                    nil];

    NSError *error = nil;

    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord
                        error:nil];

    _audioRecorder = [[AVAudioRecorder alloc]
                      initWithURL:soundFileURL
                      settings:recordSettings
                      error:&error];

    if (error)
    {
        NSLog(@"error: %@", [error localizedDescription]);
    } else {
        [_audioRecorder prepareToRecord];
    }
    //----------------------------
    //end

}

---

还有玩家:

- (IBAction)playAudioid)sender {
    [_playButton setEnabled:NO];
    if (!_audioRecorder.recording)
    {
        _stopButton.enabled = YES;
        _recordButton.enabled = NO;

        NSError *error;

        _audioPlayer = [[AVAudioPlayer alloc]
                        initWithContentsOfURL:_audioRecorder.url
                        error:&error];
        _audioPlayer.volume = 5;
        _audioPlayer.delegate = self;

        if (error)
            NSLog(@"Error: %@",
                  [error localizedDescription]);
        else
            [_audioPlayer play];
    }else{
        NSLog(@"errormax");
    }
}

我在 5 有 _audioPlayer.volume，因为再低一点，你就几乎看不到它了。但在那个音量下，它看起来和听起来都非常失真。为什么它听起来不像“语音备忘录”，它以合理的音量播放而不会失真？

什么是最好的质量设置？

---

Best Answer-推荐答案

我个人更喜欢 PCM 编码，我使用它的质量更好。

尝试:

NSDictionary *recordSettings = 
[NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey,
[NSNumber numberWithFloat:44100.0], AVSampleRateKey,
[NSNumber numberWithInt:2], AVNumberOfChannelsKey,
[NSNumber numberWithInt:16], AVLinearPCMBitDepthKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
[NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey,
nil];

或使其更具可读性:

NSDictionary * recordSetting;
recordSetting = [[NSMutableDictionary alloc] init];
[recordSetting setValue :[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];
[recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];
[recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
[recordSetting setValue :[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[recordSetting setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];

像这样调整你的函数:

- (IBAction)playAudioid)sender {
    [_playButton setEnabled:NO];
    if (!_audioRecorder.recording)
    {
        _stopButton.enabled = YES;
        _recordButton.enabled = NO;

        //force the session to play to come out of speakers!
        UInt32 sessionCategory = kAudioSessionCategory_MediaPlayback;
        AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(sessionCategory), &sessionCategory);
        UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
        AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);

        NSError *error;

        _audioPlayer = [[AVAudioPlayer alloc]
                        initWithContentsOfURL:_audioRecorder.url
                        error:&error];
        _audioPlayer.delegate = self;
        [_audioPlayer prepareToPlay];

        if (error)
            NSLog(@"Error: %@",
                  [error localizedDescription]);
        else
            [_audioPlayer play];
    }else{
        NSLog(@"errormax");
    }
}

关于ios - AVAudio 的最佳麦克风录音设置是什么？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/23323928/