iOS 音频录制

iOS实现音频录制常用的三种方式

录制之前应对AVAudioSeeion进行设置

AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryRecord error:nil]; //设置为录音模式, 如果需要可以对采样率sampleRate，缓冲时长ioBufferDuration等进行设置
[audioSession setActive:YES error:nil];

1、AVAudioRecorder：

    AVAudioRecorder的使用相对比较简单

NSError *error;
NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
                                        [NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey,
                                        [NSNumber numberWithFloat:8000], AVSampleRateKey,
                                        [NSNumber numberWithInt:2], AVNumberOfChannelsKey,
                                        [NSNumber numberWithInt:16], AVLinearPCMBitDepthKey,
                                        [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsFloatKey,
                                        [NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,nil];
AVAudioRecorder *recorder = [[AVAudioRecorder alloc] initWithURL:[NSURL fileURLWithPath:filePath] settings:settings error:&error];
if (error) {
    查看具体原因
}
recorder.delegate = self;
if ([recorder prepareToRecord]) {
    [recorder record];
}

这样就实现简单的音频录制。当然AVAudioRecorder还提供了暂停，继续等功能，代理中有录制完成、出错等回掉信息。

2、AVCaptureSession：

_captureSession = [[AVCaptureSession alloc] init]; 

AVCaptureDevice *devices = [AVCap