iOS简单直播实现（二：推流）

　推流用的是一个第三方的IFLiveKit框架。这个框架基于rtmp协议的，c语言和oc语言分开的非常清楚，对oc语言非常友好，使用起来相对简单。

　　IFLiveKit内部集成了GPUIImage。内部实现了图片渲染等美艳效果。减少了开发时候美艳效果的调试。

　　需求：创建一个简单的推流页面。包含功能有：1.推流状态监听。2.切换摄像头。3.切换美艳效果。4.开关推流。

一.推流之前需要检查摄像头和麦克风等权限是否开启，并启动摄像头，核心代码如下：

//判断是否有摄像头
    if(![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
        [self showInfo:@"您的设备没有摄像头或者相关的驱动, 不能进行直播"];
        return;
    }
    //判断是否有摄像头权限
    AVAuthorizationStatus  authorizationStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (authorizationStatus == AVAuthorizationStatusRestricted|| authorizationStatus == AVAuthorizationStatusDenied) {
        [self showInfo:@"app需要访问您的摄像头。\n请启用摄像头-设置/隐私/摄像头"];
        return ;
    }
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    if ([audioSession respondsToSelector:@selector(requestRecordPermission:)]) {
        [audioSession performSelector:@selector(requestRecordPermission:) withObject:^(BOOL granted) {
            if (granted) {
                return YES;
            }
            else {
                [self showInfo:@"app需要访问您的麦克风。\n请启用麦克风-设置/隐私/麦克风"];
                return NO;
            }
        }];
    }

二.创建一个按钮.点击开始推流代码如下：

- (LFLiveSession*)session{
    if(!_session){
        /***   默认分辨率368 ＊ 640  音频：44.1 iphone6以上48  双声道  方向竖屏 ***/
        _session = [[LFLiveSession alloc] initWithAudioConfiguration:[LFLiveAudioConfiguration defaultConfiguration] videoConfiguration:[LFLiveVideoConfiguration defaultConfigurationForQuality:LFLiveVideoQuality_Medium2]];
        
        /**    自己定制高质量音频128K 分辨率设置为720*1280 方向竖屏 */
        /*
         LFLiveAudioConfiguration *audioConfiguration = [LFLiveAudioConfiguration new];
         audioConfiguration.numberOfChannels = 2;
         audioConfiguration.audioBitrate = LFLiveAudioBitRate_128Kbps;
         audioConfiguration.audioSampleRate = LFLiveAudioSampleRate_44100Hz;
         
         LFLiveVideoConfiguration *videoConfiguration = [LFLiveVideoConfiguration new];
         videoConfiguration.videoSize = CGSizeMake(720, 1280);
         videoConfiguration.videoBitRate = 800*1024;
         videoConfiguration.videoMaxBitRate = 1000*1024;
         videoConfiguration.videoMinBitRate = 500*1024;
         videoConfiguration.videoFrameRate = 15;
         videoConfiguration.videoMaxKeyframeInterval = 30;
         videoConfiguration.orientation = UIInterfaceOrientationPortrait;
         videoConfiguration.sessionPreset = LFCaptureSessionPreset720x1280;
         
         _session = [[LFLiveSession alloc] initWithAudioConfiguration:audioConfiguration videoConfiguration:videoConfiguration liveType:LFLiveRTMP];
         */
        
        // 设置代理
        _session.delegate = self;
        _session.running = YES;
        _session.preView = self.livingPreView;
    }
    return _session;
}

- (IBAction)startTouched:(id)sender {
    LFLiveStreamInfo *stream = [LFLiveStreamInfo new];
    // 本地推流地址
    stream.url = @"rtmp://192.168.199.131:1935/rtmplive/room";
    self.rtmpUrl = stream.url;
    [self.session startLive:stream];
}

3.创建一个按钮点击关闭推流，代码如下

- (IBAction)endTouched:(id)sender {
    // 结束直播
    [self.session stopLive];
    self.stateLable.text = [NSString stringWithFormat:@"状态: 直播被关闭\nRTMP: %@", self.rtmpUrl];
}

4.创建一个按钮点击切换前后摄像头，代码如下

- (IBAction)camaBtnTouched:(id)sender {
    AVCaptureDevicePosition devicePositon = self.session.captureDevicePosition;
    self.session.captureDevicePosition = (devicePositon == AVCaptureDevicePositionBack) ? AVCaptureDevicePositionFront : AVCaptureDevicePositionBack;
    NSLog(@"切换前置/后置摄像头");
}

5.创建一个按钮设置美艳功能，代码如下

- (IBAction)beautiyBtnTouched:(id)sender {
    ((UIButton*)sender).selected = !((UIButton*)sender).selected;
    // 默认是开启了美颜功能的
    self.session.beautyFace = !self.session.beautyFace;
}

6.推流状态监听，接受代理，代码如下：

#pragma mark -- LFStreamingSessionDelegate
/** live status changed will callback */
- (void)liveSession:(nullable LFLiveSession *)session liveStateDidChange:(LFLiveState)state{
    NSString *tempStatus;
    switch (state) {
        case LFLiveReady:
            tempStatus = @"准备中";
            break;
        case LFLivePending:
            tempStatus = @"连接中";
            break;
        case LFLiveStart:
            tempStatus = @"已连接";
            break;
        case LFLiveStop:
            tempStatus = @"已断开";
            break;
        case LFLiveError:
            tempStatus = @"连接出错";
            break;
        default:
            break;
    }
    self.stateLable.text = [NSString stringWithFormat:@"状态: %@\nRTMP: %@", tempStatus, self.rtmpUrl];
}

/** live debug info callback */
- (void)liveSession:(nullable LFLiveSession *)session debugInfo:(nullable LFLiveDebug*)debugInfo{
    
}

/** callback socket errorcode */
- (void)liveSession:(nullable LFLiveSession*)session errorCode:(LFLiveSocketErrorCode)errorCode{
    
}

6.自己也需要看到自己的推流画面，并观察美艳效果，代码如下：

- (UIView *)livingPreView
{
    if (!_livingPreView) {
        UIView *livingPreView = [[UIView alloc] initWithFrame:self.view.bounds];
        livingPreView.backgroundColor = [UIColor clearColor];
        livingPreView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
        [self.view insertSubview:livingPreView atIndex:0];
        _livingPreView = livingPreView;
    }
    return _livingPreView;
}

至此，完成了推流工作。