音频播放AVAudioPlayer，AVAudioRecorder，AVAudioSession

AVAudioPlayer

• 播放对象

  self.player = [[AVAudioPlayer alloc]initWithContentsOfURL:self.fileUrl error:nil];
    
    // 3.音频信息
    NSString *msg = [NSString stringWithFormat:@"音频文件声道数:%ld\n 音频文件持续时间:%g",self.player.numberOfChannels,self.player.duration];

    
    NSLog(@"%@",msg);
    
    if (self.player) {
        
        [self.player prepareToPlay];
        
        [self.player play];
        
    }

AVAudioRecorder

• 录音对象

//(1)url
    NSString *urlStr = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/recoder.aac"];
    
    //删除之前的录音
    [[NSFileManager defaultManager]removeItemAtPath:urlStr error:nil];
    
    
    self.fileUrl = [NSURL fileURLWithPath:urlStr];
    
    
    
    //(2)设置录音的音频参数
    /*
     1 ID号:acc
     2 采样率(HZ):每秒从连续的信号中提取并组成离散信号的采样个数
     3 通道的个数:(1 单声道 2 立体声)
     4 采样位数(8 16 24 32) 衡量声音波动变化的参数
     5 大端或者小端 (内存的组织方式)
     6 采集信号是整数还是浮点数
     7 音频编码质量
     
     
     */
    NSDictionary *info = @{
                           AVFormatIDKey:[NSNumber numberWithInt:kAudioFormatMPEG4AAC],//音频格式
                           AVSampleRateKey:@8000,//采样率
                           AVNumberOfChannelsKey:@1,//声道数
                           AVLinearPCMBitDepthKey:@8,//采样位数
                           AVLinearPCMIsBigEndianKey:@NO,
                           AVLinearPCMIsFloatKey:@NO,
                           AVEncoderAudioQualityKey:[NSNumber numberWithInt:AVAudioQualityHigh],
                           
                           };
    
    
    /*
     url:录音文件保存的路径
     settings: 录音的设置
     error:错误
     */
    
    NSError * error;
    
    self.recorder = [[AVAudioRecorder alloc]initWithURL:self.fileUrl settings:info error:&error];
    
    self.recorder.delegate = self;
    
    if(error) {
        NSLog(@"错误%@", error); // 在这里我们简单打印错误, 在实际项目中我们要做容错判断
    }
    
   BOOL isno = [self.recorder prepareToRecord];
    
    if (!isno) {
        NSLog(@"失败");
    }
    
    [self.recorder record];

AVAudioSession

• 硬件设置单例

//开启扩音
   self.section = [AVAudioSession sharedInstance];
    
    NSError *sessionError;
    
    [self.section setCategory:AVAudioSessionCategoryPlayAndRecord error:&sessionError];
    
    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    AudioSessionSetProperty (
                             kAudioSessionProperty_OverrideAudioRoute,
                             sizeof (audioRouteOverride),
                             &audioRouteOverride
                             );
    
    if(self.section == nil)
        
        NSLog(@"Error creating session: %@", [sessionError description]);
    
    else
        [self.section setActive:YES error:nil];