AVFoundation之录音及播放

录音

在开始录音前，要把会话方式设置成AVAudioSessionCategoryPlayAndRecord

//设置为播放和录音状态，以便可以在录制完之后播放录音
    AVAudioSession *session = [AVAudioSession sharedInstance];
    NSError *setCategoryError = nil;
    [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&setCategoryError];
    NSError *activationError = nil;
    [session setActive:YES error:&activationError];

创建AVAudioRecorder

给出录音存放的地址，录音的设置等

//录音存放位置
-(NSURL *) getRecordAudioPath{
    NSString *urlStr=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    //#define kRecordAudioFile @"myRecord.caf"
    urlStr=[urlStr stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.caf",[[NSUUID UUID]UUIDString]]];
    NSLog(@"save file path at:%@",urlStr);
    NSURL *url=[NSURL fileURLWithPath:urlStr];
    return url;
}

- (void) startRecord{
    if (recorder.isRecording) {
        return;
    }
    recorderUrl = [self getRecordAudioPath];

    NSError *err =nil;
    NSMutableDictionary *dicM=[NSMutableDictionary dictionary];
    //    [dicM setValue :[NSNumber numberWithInt:kAudioFormatAppleIMA4] forKey:AVFormatIDKey];

    //设置录音格式
    [dicM setObject:@(kAudioFormatLinearPCM) forKey:AVFormatIDKey];
    //设置录音采样率，8000是电话采样率，对于一般录音已经够了
    [dicM setObject:@(8000) forKey:AVSampleRateKey];
    //设置通道,这里采用单声道
    [dicM setObject:@(1) forKey:AVNumberOfChannelsKey];
    //每个采样点位数,分为8、16、24、32
    [dicM setObject:@(8) forKey:AVLinearPCMBitDepthKey];
    //是否使用浮点数采样
    [dicM setObject:@(YES) forKey:AVLinearPCMIsFloatKey];

    recorder = [[AVAudioRecorder alloc]initWithURL:recorderUrl settings:dicM error:&err];
    recorder.delegate = self;
    ////如果要监控声波则必须设置为YES
    recorder.meteringEnabled = YES;
    [recorder updateMeters];
    if (err) {
        NSLog(@"创建录音机对象时发生错误，错误信息：%@",err.localizedDescription);
        recorder = nil;
        return ;
    }
    [recorder prepareToRecord];
    [recorder record];

}

录制暂停

    //暂停录音，且可以继续录音
    [recorder pause];
   //[recorder record];

录制结束

    //录制结束，录音文件关闭,会执行代理方法audioRecorderDidFinishRecording/* stops recording. closes the file. */
    [recorder stop];

代理方法

pragma mark — AVAudioRecorderDelegate

-(void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag
{
NSLog(@”录音完成!”);

}
-(void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder )recorder error:(NSError )error
{
NSLog(@”录音出错!”);

}

播放录音

创建AVAudioPlayer，AVAudioPlayer播放本地音频。

    NSError *err =nil;
    player = [[AVAudioPlayer alloc]initWithContentsOfURL:recorderUrl error:&err];
    player.delegate = self;
    //设置音乐播放次数  -1为一直循环
    player.numberOfLoops = 0;
    //开启仪表计数功能
    player.meteringEnabled = YES;
    [player updateMeters];
    //    player.enableRate = YES;
    //设置左右声道 left:-1,center:0.0,right =1;
    player.pan = 0.0;
    //设置音量，其值0.0～1.0
    player.volume = 0.6;
    [player prepareToPlay];
    [player play];

播放代理AVAudioPlayerDelegate

#pragma mark- AVAudioPlayerDelegate

-(void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer *)player error:(NSError *)error
{
    NSLog(@"player 播放失败%@",error);

}
-(void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
    NSLog(@"player:%@ 播放完成%d",player,flag);
    //    //根据实际情况播放完成可以将会话关闭，其他音频应用继续播放
    //    [[AVAudioSession sharedInstance]setActive:NO error:nil];
    AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
    playBtn.selected = NO;

}