IPhone之AVAudioRecorder

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

//获取document目录的路径

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1. - (NSString*) documentsPath {
2.  if (! _documentsPath) {
3.   NSArray *searchPaths =
4.    NSSearchPathForDirectoriesInDomains
5.    (NSDocumentDirectory, NSUserDomainMask, YES);
6.   _documentsPath = [searchPaths objectAtIndex: 0];
7.   [_documentsPath retain];
8.  }
9.  return _documentsPath;
10. }
12. //(document目录的路径)
13.  NSString *destinationString = [[self documentsPath]
14.    stringByAppendingPathComponent:filenameField.text];
15.  NSURL *destinationURL = [NSURL fileURLWithPath: destinationString];
16. //初始化AVAudioRecorder
17.  NSError *recorderSetupError = nil;
18.  AVAudioRecorder audioRecorder = [[AVAudioRecorder alloc] initWithURL:destinationURL
19.    settings:recordSettings error:&recorderSetupError];
20.  [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)

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1. NSMutableDictionary *recordSettings =
2.   [[NSMutableDictionary alloc] initWithCapacity:10];
3.   //1 ID号
4.   [recordSettings setObject:
5.    [NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];
6.   float sampleRate =
7.    [pcmSettingsViewController.sampleRateField.text floatValue];
8.   //2 采样率
9.   [recordSettings setObject:
10.    [NSNumber numberWithFloat:sampleRate] forKey: AVSampleRateKey];
12.   //3 通道的数目
13.   [recordSettings setObject:
14.    [NSNumber numberWithInt:
15.     (pcmSettingsViewController.stereoSwitch.on ? 2 : 1)]
16.    forKey:AVNumberOfChannelsKey];
17.   int bitDepth =
18.    [pcmSettingsViewController.sampleDepthField.text intValue];
20.   //4 采样位数  默认 16
21.   [recordSettings setObject:
22.    [NSNumber numberWithInt:bitDepth] forKey:AVLinearPCMBitDepthKey];
24.   //5
25.   [recordSettings setObject:
26.    [NSNumber numberWithBool:
27.      pcmSettingsViewController.bigEndianSwitch.on]
28.     forKey:AVLinearPCMIsBigEndianKey];
30.   //6 采样信号是整数还是浮点数
31.   [recordSettings setObject:
32.    [NSNumber numberWithBool:
33.      pcmSettingsViewController.floatingSamplesSwitch.on]
34.     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

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1. -(void) startRecording {
2.  [audioRecorder record];
3. }
4. -(void) pauseRecording {
5.  [audioRecorder pause];
6.  recordPauseButton.selected = NO;
7. }
8. -(void) stopRecording {
9.  [audioRecorder stop];
10. }