xcode：使用AVFoundation錄制音頻后如何保存音頻文件

Question

我瀏覽了與該主題相關的各種帖子，但是答案並沒有真正的幫助。 我使用本教程來實現音頻文件的錄制和回放。 似乎缺少的是如何永久保存記錄。 當我退出應用程序時，聲音文件在那里，但是里面什么也沒有。 我什至不知道它是保存rocerd還是只是創建文件。 這是一個代碼示例：

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

tempRecFile = [NSURL fileURLWithPath:soundFilePath];

NSDictionary *recSettings = [NSDictionary 
                                    dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithInt:AVAudioQualityMin],
                                    AVEncoderAudioQualityKey,
                                    [NSNumber numberWithInt:16], 
                                    AVEncoderBitRateKey,
                                    [NSNumber numberWithInt: 2], 
                                    AVNumberOfChannelsKey,
                                    [NSNumber numberWithFloat:44100.0], 
                                    AVSampleRateKey,
                                    nil];

recorder = [[AVAudioRecorder alloc] initWithURL:tempRecFile settings:recSettings error:nil];
[recorder setDelegate:self];
[recorder prepareToRecord];
[recorder record];

我在這里看到了可能解決此問題的方法，但是由於我是iOS的新手，所以我沒有真正了解它，或者它對我不起作用。

請幫助並提供代碼示例。 我閱讀了有關AVFoundation和其他類的文檔，但沒有得到積極的結果。

SOS :)

UPDATE這是我的錄制方法：

-(IBAction)recording{
    //***** METHOD for recording

    if(isNotRecording){
        isNotRecording = NO;
        [recButton setTitle:@"Stop"  forState:UIControlStateNormal];
        recStateLabel.text = @"Recording";

        [recorder setDelegate:self];
        [recorder prepareToRecord];
        [recorder record];

    }
    else{
        isNotRecording = YES;
        [recButton setTitle:@"Rec Begin" forState:UIControlStateNormal];
        playButton.hidden = NO;
        recStateLabel.text = @"Not recording";
        [recorder stop];
    }


}

這是我的viewDidLoad：

- (void)viewDidLoad
{
    //record sound test code - start
    isNotRecording = YES;
    //playButton.hidden = YES;
    recStateLabel.text = @"Not recording";

    AVAudioSession *audioSession = [AVAudioSession sharedInstance];

    [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

    [audioSession setActive:YES error:nil];
    //record sound test code -  END

    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

    // code for generating the sound file that is to be saved
    NSArray *dirPaths;
    NSString *docsDir;

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

    NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

    NSDictionary *recordSettings = [NSDictionary 
                                    dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithInt:AVAudioQualityMin],
                                    AVEncoderAudioQualityKey,
                                    [NSNumber numberWithInt:16], 
                                    AVEncoderBitRateKey,
                                    [NSNumber numberWithInt: 2], 
                                    AVNumberOfChannelsKey,
                                    [NSNumber numberWithFloat:44100.0], 
                                    AVSampleRateKey,
                                    nil];

    NSError *error = nil;

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

    if (error)
    {
        NSLog(@"error: %@", [error localizedDescription]);

    } else {
        [recorder prepareToRecord];
    }

}

這是我的playBack方法：

-(IBAction)playback{
    //AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:temporaryRecFile error:nil];
    NSError *error;
    // setting the uri of the formed created file
    NSArray *dirPaths;
    NSString *docsDir;



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

NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

AVAudioPlayer *player = [[AVAudioPlayer alloc]initWithContentsOfURL:soundFileURL error:&error];



[player setNumberOfLoops:0];
[player prepareToPlay];
[player setVolume:1];
[player play];
NSLog(@"URL je: %@", soundFileURL);


//method 2
if (error)
    NSLog(@"Error: %@", 
          [error localizedDescription]);
else
{

    [player play];
    if(player.isPlaying==YES)
    {
        NSLog(@"It's playing");
    }
}

}

我希望這可以使我清楚地知道自己在做什么。 有什么建議我可能錯了嗎？

Answer 1

問題是當您將XCode（在viewDidLoad方法中）告訴[recorder prepareToRecord]時； 它擺脫了以前錄制的音頻文件。 消除“ if”語句中的那段代碼，當您退出並返回應用程序時，音頻文件將被保存。

Answer 2

您需要停止記錄才能將數據永久保存到文件中：

[recorder stop];

Answer 3

僅供參考-“ [recorder prepareToRecord]”方法創建一個新的音頻文件，覆蓋以前的所有已記錄文件。