ios：音频和视频（未完）

前提条件：需要引入AVFoundation.frame-work、MediaPlayer.framework、CoreAudio.framework（录制音频时会用到）

AV 框架(Audio 和Video框架)里的 AVAudioPlayer类播放iOS支持的所有音频格式。AVAudioPlayer 实例的delegate属性允许我们通过事件获得通知,例如当音频播放被打断或者播放音频文件出错时。

新建一个类，类中包含一个播放器的属性。而且该类遵守AVAudioPlayerDelegate协议

@interface AVTest : UIViewController<AVAudioPlayerDelegate>@property (nonatomic,retain) AVAudioPlayer *myPlayer;

在.m文件中实现：

- (void)viewDidLoad{    [super viewDidLoad];    self.view.backgroundColor = [UIColor cyanColor];    //添加按钮，点击按钮播放音乐    UIButton *play = [UIButton buttonWithType:UIButtonTypeRoundedRect];    play.frame = CGRectMake(100, 250, 120, 40);    [play addTarget:self action:@selector(playMusic) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:play];}- (void)playMusic{    dispatch_queue_t playDispatchQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);    dispatch_async(playDispatchQueue, ^{    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"aaa" ofType:@"mp3"];    //文件中的数据首先被加载到一个 NSData 实例,然后被传递到 AVAudioPlayer 类的 initWithData:error:方法。    NSData *mp3Data = [NSData dataWithContentsOfFile:filePath];    myPlayer = [[AVAudioPlayer alloc] initWithData:mp3Data error:nil];    if (self.myPlayer != nil)    {        //设置播放器代理，并播放        self.myPlayer.delegate = self;        [self.myPlayer play];    }    });}

处理播放音频时的中断

AVAudioPlayerDelegate中有处理中断的方法：

//当中断发生时调用这个方法- (void)audioPlayerBeginInterruption:(AVAudioPlayer *)player{    //do something    NSLog(@"%s,%d",__FUNCTION__,__LINE__);    NSLog(@"Here is a interruption!");}//当中断结束时调用这个方法- (void)audioPlayerEndInterruption:(AVAudioPlayer *)player withFlags:(NSUInteger)flags{    if (flags == AVAudioSessionInterruptionFlags_ShouldResume&&self.myPlayer != nil)     {        [self.myPlayer play];    }}

(遵守AVAudioRecorderDelegate协议)录制音频：

增加一个AVAudioRecorder属性：

@property (nonatomic,retain) AVAudioRecorder *audioRecorder;

初始化AVAudioRecorder的方法initWithURL:settings:error:的setting参数，很多值都可以保存在这个setting字典里:

• AVFormatIDKey录音的格式,可以是：kAudioFormatLinearPCM、kAudioFormatAppleLossless

• AVSampleRateKey录制音频的采样率

• AVNumberOfChannelsKey录制音频的频道编号

• AVEncoderAudioQualityKey录制音频的质量,可以是：AVAudioQualityMin、AVAudioQualityLow、AVAudioQualityMedium、AVAudioQualityHigh、AVAudioQualityMax

初始化 AVAudioRecorder时,我们使用了一个dictionary作为音频录制器的初始化方法中的setting参数。这个dictionary用audioRecordingSettings方法创建。实现如下:

- (NSDictionary *) audioRecordingSettings{NSDictionary *result = nil;/* 我们在 dictionary 中初始化录制音频的选项。稍后我们会用这个 dictionary 音频录制器*/NSMutableDictionary *settings = [[NSMutableDictionary alloc] init];[settingssetValue:[NSNumber numberWithInteger:kAudioFormatAppleLossless] forKey:AVFormatIDKey];[settingssetValue:[NSNumber numberWithFloat:44100.0f] forKey:AVSampleRateKey];[settingssetValue:[NSNumber numberWithInteger:1] forKey:AVNumberOfChannelsKey];[settingssetValue:[NSNumber numberWithInteger:AVAudioQualityLow] forKey:AVEncoderAudioQualityKey];result = [NSDictionary dictionaryWithDictionary:settings];return result; }

添加一个录音按钮：

//添加录音按钮    UIButton *record = [UIButton buttonWithType:UIButtonTypeRoundedRect];    record.frame = CGRectMake(100, 300, 120, 40);    [record addTarget:self action:@selector(recordAudio) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:record];

录音存放路径：

- (NSString *) audioRecordingPath{     //返回录音存放路径    NSArray *folders = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);    NSString *documentsFolder = [folders objectAtIndex:0];    NSString *result = [documentsFolder stringByAppendingPathComponent:@"Recording.m4a"];    return result;}

录音以及结束录音方法：

- (void)recordAudio{    NSString *recordPath = [self audioRecordingPath];    NSURL *recordURL = [NSURL fileURLWithPath:recordPath];    audioRecorder = [[AVAudioRecorder alloc] initWithURL:recordURL settings:[self audioRecordingSettings] error:nil];    if (self.audioRecorder != nil)     {        self.audioRecorder.delegate = self;        if ([self.audioRecorder prepareToRecord] && [self.audioRecorder record])         {            NSLog(@"Successfully started to record!");            /* 5 秒后,我们终止录制过程 ,具体录制时间可以再写一个接口*/            [self performSelector:@selector(stopRecordingOnAudioRecorder:)                       withObject:self.audioRecorder afterDelay:5.0f];        }    }}- (void)stopRecordingOnAudioRecorder :(AVAudioRecorder *)paramRecorder{    //停止录音    [self.audioRecorder stop];}

在AVAudioRecorderDelegate协议中也存在像AVAudioPlayerDelegate中断与结束的方法：

- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag;- (void)audioRecorderBeginInterruption:(AVAudioRecorder *)recorder;/* Currently the only flag is AVAudioSessionInterruptionFlags_ShouldResume. */- (void)audioRecorderEndInterruption:(AVAudioRecorder *)recorder withFlags:(NSUInteger)flags NS_AVAILABLE_IOS(4_0);