iOS 音頻錄製

建立Empty Applicaton,添加HomeViewController檔案。還是看代碼吧，將理論太枯燥，理論在代碼中會提到。  HomeViewController.h代碼： #import <UIKit/UIKit.h> #import <AVFoundation/AVFoundation.h>   @interface HomeViewController : UIViewController <AVAudioRecorderDelegate, AVAudioPlayerDelegate>{   }   @property (nonatomic, retain) AVAudioRecorder *audioRecorder; @property (nonatomic, retain) AVAudioPlayer *audioPlayer;   - (NSString *)audioRecordingPath; - (NSDictionary *)audioRecordingSettings;   @end   HomeViewController.m代碼：   #import "HomeViewController.h"   @interface HomeViewController ()   @end   @implementation HomeViewController   @synthesize audioPlayer; @synthesize audioRecorder;   //設定錄製的音頻檔案的位置 - (NSString *)audioRecordingPath{       NSString *result = nil;     NSArray *folders = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);     NSString *documentsFolde = [folders objectAtIndex:0];     result = [documentsFolde stringByAppendingPathComponent:@"Recording.m4a"];     return (result); }   //在初始化AVAudioRecord執行個體之前，需要進行基本的錄音設定 - (NSDictionary *)audioRecordingSettings{       NSDictionary *result = nil;          NSMutableDictionary *settings = [[[NSMutableDictionary alloc] init] autorelease];//錄音時所必要參數設定          [settings setValue:[NSNumber numberWithInteger:kAudioFormatAppleLossless]                  forKey:AVFormatIDKey];          [settings setValue:[NSNumber numberWithFloat:44100.0f] forKey:AVSampleRateKey];          [settings setValue:[NSNumber numberWithInteger:1] forKey:AVNumberOfChannelsKey];          [settings setValue:[NSNumber numberWithInteger:AVAudioQualityLow]                  forKey:AVEncoderAudioQualityKey];          result = [NSDictionary dictionaryWithDictionary:settings];          return (result); }   //停止音訊錄製 - (void)stopRecordingOnAudioRecorder:(AVAudioRecorder *)recorder{       [recorder stop]; }   //當AVAudioRecorder對象錄音終止的時候會調用audioRecorderDidFinishRecording:successfully:方法 - (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag{       //如果flag為真，代表錄音正常結束，使用AVAudioPlayer將其播放出來，否則日誌記錄失敗原因     if (flag == YES) {         NSLog(@"錄音完成。");         NSError *playbackError = nil;         NSError *readingError = nil;         NSData *fileData = [NSData dataWithContentsOfFile:[self audioRecordingPath] options:NSDataReadingMapped error:&readingError];                  AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithData:fileData                                                                   error:&playbackError];                  self.audioPlayer = newPlayer;         [newPlayer release];                  if (self.audioPlayer != nil) {             self.audioPlayer.delegate = self;             if ([self.audioPlayer prepareToPlay] == YES &&                  [self.audioPlayer play] == YES) {                 NSLog(@"開始播放錄製的音頻。");             } else {                 NSLog(@"不能播放錄製的音頻。");             }         }else {             NSLog(@"音頻播放失敗。");         }              } else {         NSLog(@"錄音過程意外終止。");     }     self.audioRecorder = nil; }   - (void)viewDidLoad {     [super viewDidLoad];          NSError *error = nil;     NSString *pathOfRecordingFile = [self audioRecordingPath];          NSURL *audioRecordingUrl = [NSURL fileURLWithPath:pathOfRecordingFile];          AVAudioRecorder *newRecorder = [[AVAudioRecorder alloc]                                      initWithURL:audioRecordingUrl                                      settings:[self audioRecordingSettings]                                     error:&error];     self.audioRecorder = newRecorder;     [newRecorder release];          if (self.audioRecorder != nil) {         self.audioRecorder.delegate = self;                  if ([self.audioRecorder prepareToRecord] == YES &&             [self.audioRecorder record] == YES) {             //如果audioRecorder執行個體化成功，則開始錄製聲音，並且通過performSelector方法設定在錄製聲音10s以後執行stopRecordingOnAudioRecorder方法，用於停止錄音             NSLog(@"錄製聲音開始。");                          [self performSelector:@selector(stopRecordingOnAudioRecorder:)                        withObject:self.audioRecorder                        afterDelay:10.0f];                      } else {             NSLog(@"錄製失敗。");             self.audioRecorder =nil;         } } else {     NSLog(@"auioRecorder執行個體建立失敗。"); } }   - (void)viewDidUnLoad{       if (self.audioRecorder != nil) {         if ([self.audioRecorder isRecording] == YES) {             [self.audioRecorder stop];         }         self.audioRecorder = nil;     }          if (self.audioPlayer != nil) {         if ([self.audioPlayer isPlaying] == YES) {             [self.audioPlayer stop];         }         self.audioPlayer = nil;     } }   - (void)dealloc{       [audioPlayer release];     [audioRecorder release];     [super dealloc]; }   @end    PS: 錄製音頻時所必要參數設定   AVFormatIDKey  錄製音訊格式。 kAudioFormatLinearPCM: lpcm格式  kAudioFormatAC3: ac-3格式 kAudioFormatMPEG4AAC: aac格式 kAudioFormatMPEG4CELP: celp格式  kAudioFormatMPEG4HVXC: hvxc格式  kAudioFormatMPEG4Layer1: mp1格式  kAudioFormatMPEG4Layer2: mp2 格式  kAudioFormatMPEG4Layer3: mp3 格式  kAudioFormatTimeCode: time格式  kAudioFormatMIDIStream: midi格式  kAudioFormatAppleLossless：alac格式     AVSampleRateKey 錄製音頻時的採用視頻 AVNumberOfChannelsKey  錄製音頻時的通道數量 AVEncoderAudioQualityKey  錄製音訊品質  AVAudioQualityMin  AVAudioQualityLow AVAudioQualityMedium AVAudioQualityHigh AVAudioQualityMax