iOS 直播-获取音频(视频)数据

---

//
//  ViewController.m
//  capture-test
//
//  Created by caoxu on 16/6/3.
//  Copyright © 2016年 caoxu. All rights reserved.
//

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>

@interface ViewController ()<AVCaptureAudioDataOutputSampleBufferDelegate>


@property (nonatomic, strong) AVCaptureSession * session;
@property (nonatomic, strong) AVCaptureAudioDataOutput *audioOutput;
@property (nonatomic, strong) dispatch_queue_t audioQueue;
@property (nonatomic, strong) AVCaptureConnection *audioConnection;



@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.session = [[AVCaptureSession alloc]init];
    
    NSError *error = nil;
    AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    
    if (error) {
        
        NSLog(@"Error getting video input device: %@", error.description);
        
    }
    if ([self.session canAddInput:audioInput]) {
        
        [self.session addInput:audioInput];
        
    }
    
    // 配置采集输出，即我们取得音频的接口
    self.audioQueue = dispatch_queue_create("Audio Capture Queue", DISPATCH_QUEUE_SERIAL);
    self.audioOutput = [[AVCaptureAudioDataOutput alloc] init];
    [self.audioOutput setSampleBufferDelegate:self queue:self.audioQueue];
    
    if ([self.session canAddOutput:self.audioOutput]) {
        [self.session addOutput:self.audioOutput];
    }
    
    // 保存Connection，用于在SampleBufferDelegate中判断数据来源（是Video/Audio？）
    self.audioConnection = [self.audioOutput connectionWithMediaType:AVMediaTypeAudio];
    
    
    [self.session startRunning];
    
    
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{
    // 这里的sampleBuffer就是采集到的数据了，但它是Video还是Audio的数据，得根据connection来判断
    if (connection == self.audioConnection) {  // Audio
        
        
        NSLog(@"%@",sampleBuffer);
        
        
        NSLog(@"这里获得audio sampleBuffer，做进一步处理（编码AAC）");
        
    }
   
}


@end