#GPUImage-waterMark

完美解决GPUImage加水印的需求，在视频录制的任意时刻加自定义水印，修改水印，移除水印。 一、开启实时视频

• (void)videoFilter{ //GPUImageVideoCamera 必须声明为 全局变量或属性，否则开不到视频

  videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPreset640x480 cameraPosition:AVCaptureDevicePositionFront]; videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;

  //画面镜像 videoCamera.horizontallyMirrorFrontFacingCamera = YES;

  //视图对象 filterView = [[GPUImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, ScreenWidth, ScreenHeight)];

  filterView.center = self.view.center; [self.view insertSubview:filterView atIndex:0];

  //过滤器 beautifyFilter = [[GPUImageBeautifyFilter alloc] init]; [videoCamera addTarget:beautifyFilter]; [beautifyFilter addTarget:filterView];

  [videoCamera startCameraCapture];/到此开启视频/

  /为加水印初始化对象/ //加水印的过滤器 blendFilter = [[GPUImageAlphaBlendFilter alloc] init]; blendFilter.mix = 1.0;

  /为录制初始化对象/

  //将视频流写到文件 NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.m4v"]; unlink([pathToMovie UTF8String]); NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie]; movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(480.0, 640.0)];

  //添加录制对象 [beautifyFilter addTarget:movieWriter];

  //添加音频输入 videoCamera.audioEncodingTarget = movieWriter;

  movieWriter.shouldPassthroughAudio = YES;

} 二、录制视频

• (IBAction)clickRecord:(UIButton*)sender {

  if (sender.tag == 0) { sender.tag = 1;

    /*开启这个方法，......*/
  

// movieWriter.encodingLiveVideo = YES;

    //调用刻录方法
    [movieWriter startRecording];
    [sender setTitle:@"停止录制" forState:UIControlStateNormal];
} else {
    sender.tag = 0;
    [sender setTitle:@"开始录制" forState:UIControlStateNormal];
    //滤镜移除输出视频流对象
    [beautifyFilter removeTarget:movieWriter];
    //调用完成刻录方法
    [movieWriter finishRecording];
    //注销音频输入
    videoCamera.audioEncodingTarget = nil;
    /*水印过滤器移除录制对象*/
    [blendFilter removeTarget:movieWriter];
}

} 三、加上水印

• (IBAction)addWaterMask:(UIButton*)sender {

  if (sender.tag == 0) { sender.tag = 1;

  /初始化水印视图/ UIView *contentView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, filterView.frame.size.width,filterView.frame.size.height)]; contentView.backgroundColor = [UIColor clearColor]; UIImage *image = [UIImage imageNamed:@"waterMark"]; UIImageView *ivTemp = [[UIImageView alloc] initWithFrame:CGRectMake(0, 150, image.size.width, image.size.height)]; ivTemp.image = image; ivTemp.tag = 500; ivTemp.hidden = NO; [contentView addSubview:ivTemp];

  if (_uiElementInput) {

    [_uiElementInput removeAllTargets];
  

  } if (beautifyFilter) {

    [beautifyFilter removeTarget:filterView];
  

  }

  if (!_uiElementInput) { _uiElementInput = [[GPUImageUIElement alloc] initWithView:contentView]; } if (blendFilter) { [blendFilter removeAllTargets]; }

  [beautifyFilter addTarget:blendFilter]; [_uiElementInput addTarget:blendFilter]; [blendFilter addTarget:filterView];

  /一定要把beautyFilter的视频流对象movieWriter移除，在赋值给水印过滤器blendFilter/ [beautifyFilter removeTarget:movieWriter]; [blendFilter addTarget:movieWriter];

  __weak typeof(self) weakSelf = self; [beautifyFilter setFrameProcessingCompletionBlock:^(GPUImageOutput * filter, CMTime frameTime){ // [contentView viewWithTag:500].hidden = NO; [weakSelf.uiElementInput update];/一定要调用 GPUImageUIElement 对象的update，对每一帧图片加水印处理/ }]; // _writefilter = blendFilter;/这里是借鉴了别人的，加上好像没什么用/ } else { sender.tag = 0;

    /*显示视图的切换*/
    [blendFilter removeTarget:filterView];
    [beautifyFilter addTarget:filterView];
    
    /*视频流对象切换*/
    [blendFilter removeTarget:movieWriter];
    [beautifyFilter  addTarget:movieWriter];
  

  } }

有兴趣的同学可以继续研究水印动画、