IPhone之AVAudioRecorder

#import <AVFoundation/AVFoundation.h>  需要引入
 

//獲取document目錄的路徑 
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    - (NSString*) documentsPath {   
     if (! _documentsPath) {   
      NSArray *searchPaths =   
       NSSearchPathForDirectoriesInDomains   
       (NSDocumentDirectory, NSUserDomainMask, YES);   
      _documentsPath = [searchPaths objectAtIndex: 0];   
      [_documentsPath retain];   
     }   
     return _documentsPath;   
    }   
        
    //(document目錄的路徑)   
     NSString *destinationString = [[self documentsPath]   
       stringByAppendingPathComponent:filenameField.text];   
     NSURL *destinationURL = [NSURL fileURLWithPath: destinationString];   
    //初始化AVAudioRecorder   
     NSError *recorderSetupError = nil;   
     AVAudioRecorder audioRecorder = [[AVAudioRecorder alloc] initWithURL:destinationURL   
       settings:recordSettings error:&recorderSetupError];   
     [recordSettings release];   

第二個(gè)參數(shù)  settings是一個(gè)容納鍵值對(duì)的NSDictionary有四種一般的鍵

1:一般的音頻設(shè)置

2:線性PCM設(shè)置

3:編碼器設(shè)置

4:采樣率轉(zhuǎn)換設(shè)置

NSMutableDictionary  需要加入五個(gè)設(shè)置值(線性PCM)

    NSMutableDictionary *recordSettings =   
      [[NSMutableDictionary alloc] initWithCapacity:10];   
      //1 ID號(hào)   
      [recordSettings setObject:   
       [NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];   
      float sampleRate =   
       [pcmSettingsViewController.sampleRateField.text floatValue];   
      //2 采樣率   
      [recordSettings setObject:   
       [NSNumber numberWithFloat:sampleRate] forKey: AVSampleRateKey];   
          
      //3 通道的數(shù)目   
      [recordSettings setObject:   
       [NSNumber numberWithInt:   
        (pcmSettingsViewController.stereoSwitch.on ? 2 : 1)]   
       forKey:AVNumberOfChannelsKey];   
      int bitDepth =   
       [pcmSettingsViewController.sampleDepthField.text intValue];   
          
      //4 采樣位數(shù)  默認(rèn) 16   
      [recordSettings setObject:   
       [NSNumber numberWithInt:bitDepth] forKey:AVLinearPCMBitDepthKey];   
          
      //5   
      [recordSettings setObject:   
       [NSNumber numberWithBool:   
         pcmSettingsViewController.bigEndianSwitch.on]   
        forKey:AVLinearPCMIsBigEndianKey];   
        
      //6 采樣信號(hào)是整數(shù)還是浮點(diǎn)數(shù)   
      [recordSettings setObject:   
       [NSNumber numberWithBool:   
         pcmSettingsViewController.floatingSamplesSwitch.on]   
        forKey:AVLinearPCMIsFloatKey]   
 
 
; 

AVAudioRecorder成功創(chuàng)建后,使用他非常直接.它的三個(gè)基本方法如下

-(void) startRecording {   
 [audioRecorder record];   
}   
-(void) pauseRecording {   
 [audioRecorder pause];   
 recordPauseButton.selected = NO;   
}   
-(void) stopRecording {   
 [audioRecorder stop];   
}