iOS 音频录制

     新建Empty Applicaton,添加HomeViewController文件。还是看代码吧，将理论太枯燥，理论在代码中会提到。

 HomeViewController.h代码：

#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代码：

 

#import "HomeViewController.h"

 

@interface HomeViewController ()

 

@end

 

@implementation HomeViewController

 

@synthesize audioPlayer;

@synthesize audioRecorder;

 

//设置录制的音频文件的位置

- (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实例之前，需要进行基本的录音设置

- (NSDictionary *)audioRecordingSettings{

 

    NSDictionary *result = nil;

    

    NSMutableDictionary *settings = [[[NSMutableDictionary alloc] init] autorelease];//录音时所必需的参数设置

    

    [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);

}

 

//停止音频的录制

- (void)stopRecordingOnAudioRecorder:(AVAudioRecorder *)recorder{

 

    [recorder stop];

}

 

//当AVAudioRecorder对象录音终止的时候会调用audioRecorderDidFinishRecording:successfully:方法

- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag{

 

    //如果flag为真，代表录音正常结束，使用AVAudioPlayer将其播放出来，否则日志记录失败原因

    if (flag == YES) {

        NSLog(@"录音完成！");

        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(@"开始播放录制的音频！");

            } else {

                NSLog(@"不能播放录制的音频！");

            }

        }else {

            NSLog(@"音频播放失败！");

        }

        

    } else {

        NSLog(@"录音过程意外终止！");

    }

    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实例化成功，则开始录制声音，并且通过performSelector方法设置在录制声音10s以后执行stopRecordingOnAudioRecorder方法，用于停止录音

            NSLog(@"录制声音开始！");

            

            [self performSelector:@selector(stopRecordingOnAudioRecorder:)

                       withObject:self.audioRecorder

                       afterDelay:10.0f];

            

        } else {

            NSLog(@"录制失败！");

            self.audioRecorder =nil;

        }

} else {

    NSLog(@"auioRecorder实例创建失败！");

}

}

 

- (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: 录制音频时所必需的参数设置 

 AVFormatIDKey  录制音频的格式。

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 录制音频时的采用视频

AVNumberOfChannelsKey  录制音频时的通道数量

AVEncoderAudioQualityKey  录制音频的质量 

AVAudioQualityMin 

AVAudioQualityLow

AVAudioQualityMedium

AVAudioQualityHigh

AVAudioQualityMax