Objective C：AVFoundation Recording Issue ..

Question

先生，您認爲我的代碼錯誤是什麼......因爲我無法錄製音頻。你能幫我完成我的項目嗎？我想製作一個簡單的錄音工程。有三個按鈕（PLAY，STOP，RECORD）......順便說一句，我沒有使用nib文件。在Objective-C IM新手我的做法是純粹Programmatically..Thanks提前更多的權力..

，這是我在viewDidLoad中的代碼（）

-(void)viewDidLoad 
{ 
    [super viewDidLoad];{ 
     playButton.enabled = NO; 
    stopButton.enabled = NO; 

    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; 

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

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

    } 
    else 
    { 
     [audioRecorder prepareToRecord]; 
    } 

} 


-(void) recordButton:(UIButton *)sender 
{ 
     if (!audioRecorder.recording) 
     { 

      playButton.enabled = NO; 
      stopButton.enabled = YES; 
      [audioRecorder record]; 
      NSLog(@"Record"); 
     } 
} 


-(void)stop:(UIButton *)sender 
{ 
     stopButton.enabled = NO; 
     playButton.enabled = YES; 
     recordButton.enabled = YES; 

     if (audioRecorder.recording) 
     { 
      [audioRecorder stop]; 
      NSLog(@"Stop"); 
     } 
     else if (audioPlayer.playing) 
     { 
      [audioPlayer stop]; 
     } 
} 

-(void) playAudio:(UIButton *)sender 
{ 
    NSError *error; 
     if (!audioRecorder.recording) 
     { 
      stopButton.enabled = YES; 
      recordButton.enabled = NO; 
      NSLog(@"Play"); 
      if (audioPlayer) 
      { 


      audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:audioRecorder.url error:&error]; 

      audioPlayer.delegate = self; 
      } 
      if (error) 

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

Answer 1

蘋果提供了一個名爲SpeakHere一個示例應用程序，這將大大幫助您使用音頻文件服務創建，錄製並讀取CAF（核心音頻格式）音頻文件。

您可以在Apple的開發人員網站here上找到它。

希望這會有所幫助。

Answer 2

首先，將代碼從viewDidLoad移出到viewDidAppear或函數調用。接下來，閱讀關於AVAudioSession。簡而言之，當您分別錄製或播放時，您希望將其類別更改爲AVAudioSessionCategoryRecord或AVAudioSessionCategoryPlay。

- (void)beginRecording { 

    AVAudioSession *audioSession = [AVAudioSession sharedInstance]; 
    NSError *err = nil; 
    [audioSession setCategory:AVAudioSessionCategoryRecord error:&err]; 
    if(err){ 
    NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]); 
    return; 
    } 
    err = nil; 
    [audioSession setActive:YES error:&err]; 
    if(err){ 
    NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]); 
    return; 
    } 
    if (audioSession.inputIsAvailable) { 
    if ([audioRecorder prepareToRecord]) { 
     [audioRecorder record]; 
    } 
    else { 
     UIAlertView *alert = 
     [[UIAlertView alloc] initWithTitle:@"Error!" 
           message:@"Could not begin recording" 
           delegate:nil 
         cancelButtonTitle:@"OK" 
         otherButtonTitles:nil]; 
     [alert show]; 
     [alert release]; 
    } 
    } 
} 

- (void)stopRecording { 
    [audioRecorder stop]; 
} 

這些都是你需要開始記錄（在他們的工作對我來說是最起碼的最低參數，但你可以設置質量要作爲AppleLoseless權重一噸的任意值，但要注意分質量施** IEST在已知的星系的東西）：

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

    NSURL *url = [NSURL fileURLWithPath:filePath]; 
    NSError *err = nil; 
    self.audioRecorder = [[AVAudioRecorder alloc] initWithURL:url 
                 settings:settings 
                  error:&err]; 
    if(err){ 
     UIAlertView *alert = 
     [[UIAlertView alloc] initWithTitle:@"Warning" 
            message:[err localizedDescription] 
            delegate:nil 
         cancelButtonTitle:@"OK" 
         otherButtonTitles:nil]; 
     [alert show]; 
     [alert release]; 
     } 

請注意，我完全不顧內存管理，這個帖子是不是內存管理指南。