iphone之AVAudioRecorder

//获取document目录的路径

- (NSString*) documentsPath {

 if (! _documentsPath) {

  NSArray *searchPaths =

   NSSearchPathForDirectoriesInDomains

   (NSDocumentDirectory, NSUserDomainMask, YES);

  _documentsPath = [searchPaths objectAtIndex: 0];

  [_documentsPath retain];

 }

 return _documentsPath;

}

  

//(document目录的路径)

 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];

 

第二个参数  settings是一个容纳键值对的NSDictionary有四种一般的键

1:一般的音频设置

2:线性PCM设置

3:编码器设置

4:采样率转换设置

 

NSMutableDictionary  需要加入五个设置值(线性PCM)

NSMutableDictionary *recordSettings =

  [[NSMutableDictionary alloc] initWithCapacity:10];

  //1 ID号

  [recordSettings setObject:

   [NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];

  float sampleRate =

   [pcmSettingsViewController.sampleRateField.text floatValue];

  //2 采样率

  [recordSettings setObject:

   [NSNumber numberWithFloat:sampleRate] forKey: AVSampleRateKey];

   

  //3 通道的数目

  [recordSettings setObject:

   [NSNumber numberWithInt:

    (pcmSettingsViewController.stereoSwitch.on ? 2 : 1)]

   forKey:AVNumberOfChannelsKey];

  int bitDepth =

   [pcmSettingsViewController.sampleDepthField.text intValue];

   

  //4 采样位数  默认 16

  [recordSettings setObject:

   [NSNumber numberWithInt:bitDepth] forKey:AVLinearPCMBitDepthKey];

   

  //5

  [recordSettings setObject:

   [NSNumber numberWithBool:

     pcmSettingsViewController.bigEndianSwitch.on]

    forKey:AVLinearPCMIsBigEndianKey];

 

  //6 采样信号是整数还是浮点数

  [recordSettings setObject:

   [NSNumber numberWithBool:

     pcmSettingsViewController.floatingSamplesSwitch.on]

    forKey:AVLinearPCMIsFloatKey];

 

AVAudioRecorder成功创建后,使用他非常直接.它的三个基本方法如下

-(void) startRecording {

 [audioRecorder record];

}

-(void) pauseRecording {

 [audioRecorder pause];

 recordPauseButton.selected = NO;

}

-(void) stopRecording {

 [audioRecorder stop];

}

一个setting的设置

- (NSDictionary *) audioRecordingSettings

{

    

   NSDictionary *result =nil;

    NSMutableDictionary *settings = [[NSMutableDictionaryalloc]init];

    [settings

     setValue:[NSNumbernumberWithInteger:AVAudioQualityMin]forKey:AVEncoderAudioQualityKey];

    [settings

     setValue:[NSNumbernumberWithFloat:MP3_SAMPLERATE]forKey:AVSampleRateKey];//44100.0f

    [settings

     setValue:[NSNumbernumberWithInteger:2]forKey:AVNumberOfChannelsKey];

    [settings

     setValue:[NSNumbernumberWithInteger:16]forKey:AVEncoderBitRateKey];

    result = [NSDictionarydictionaryWithDictionary:settings];

   return result;

    

    

}

#define MP3_SAMPLERATE 16000.0f

保存下 以便以后的使用！

本文转载自：http://www.cnblogs.com/lm3515/archive/2011/03/11/1981381.html