IPhone之AVAudioRecorder

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

 

//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];

}