初探GPUImage(三)水印篇

{
    GPUImageMovie *movieFile;
    GPUImageOutput *filter; 
// 强引用  取消警告
    GPUImageMovieWriter *movieWriter;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    GPUImageView *filterView = [[GPUImageView alloc] initWithFrame:self.view.frame];
    self.view = filterView;
    
    self.mLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
    self.mLabel.textColor = [UIColor redColor];
    [self.view addSubview:self.mLabel];
    
    // 滤镜
    filter = [[GPUImageDissolveBlendFilter alloc] init];
    [(GPUImageDissolveBlendFilter *)filter setMix:0.5];
    
    // 播放
    NSURL *sampleURL = [[NSBundle mainBundle] URLForResource:@"qidong" withExtension:@"mp4"];
    AVAsset *asset = [AVAsset assetWithURL:sampleURL];
    CGSize size = self.view.bounds.size;
    movieFile = [[GPUImageMovie alloc] initWithAsset:asset];
    //    这使当前视频处于基准测试的模式，记录并输出瞬时和平均帧时间到控制台 每隔一段时间打印： Current frame time : 51.256001 ms，直到播放或加滤镜等操作完毕
    movieFile.runBenchmark = YES;
    /*  控制GPUImageView预览视频时的速度是否要保持真实的速度。
     如果设为NO，则会将视频的所有帧无间隔渲染，导致速度非常快。
     设为YES，则会根据视频本身时长计算出每帧的时间间隔，然后每渲染一帧，就sleep一个时间间隔，从而达到正常的播放速度。*/
    movieFile.playAtActualSpeed = YES;
    
    // 水印
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
    label.text = @"我是水印";
    label.font = [UIFont systemFontOfSize:30];
    label.textColor = [UIColor redColor];
    [label sizeToFit];

    UIImageView *imageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"test.jpg"]];
    UIView *subView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, size.width, size.height)];
    subView.backgroundColor = [UIColor clearColor];
    imageView.center = CGPointMake(subView.bounds.size.width / 2, subView.bounds.size.height / 2);
    [subView addSubview:imageView];
    [subView addSubview:label];
    


    GPUImageUIElement *uielement = [[GPUImageUIElement alloc] initWithView:subView];
    
    /*
     *moveWriter用来记录保存视频
     */
    NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.m4v"];
    unlink([pathToMovie UTF8String]);
    NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie];
    
    movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(640.0, 480.0)];
    
    GPUImageFilter* progressFilter = [[GPUImageFilter alloc] init];
    [movieFile addTarget:progressFilter];
    // 强引用
    [progressFilter addTarget:filter];
    [uielement addTarget:filter];
    movieWriter.shouldPassthroughAudio = YES;
    movieFile.audioEncodingTarget = movieWriter;
    [movieFile enableSynchronizedEncodingUsingMovieWriter:movieWriter];
    // 显示到界面
    [filter addTarget:filterView];
    [filter addTarget:movieWriter];
    
    [movieWriter startRecording];
    [movieFile startProcessing];
    
    
    CADisplayLink* dlink = [CADisplayLink displayLinkWithTarget:self selector:@selector(updateProgress)];
    [dlink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
    [dlink setPaused:NO];
    
    __weak typeof(self) weakSelf = self;
    //设置帧处理完成  写动画在这里
    [progressFilter setFrameProcessingCompletionBlock:^(GPUImageOutput *output, CMTime time) {
        CGRect frame = imageView.frame;
        frame.origin.x += 1;
        frame.origin.y += 1;
        imageView.frame = frame;
        [uielement updateWithTimestamp:time];
    }];
    //完成
    [movieWriter setCompletionBlock:^{
        __strong typeof(self) strongSelf = weakSelf;
        [strongSelf->filter removeTarget:strongSelf->movieWriter];
        [strongSelf->movieWriter finishRecording];
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(pathToMovie))
        {
            [library writeVideoAtPathToSavedPhotosAlbum:movieURL completionBlock:^(NSURL *assetURL, NSError *error)
             {
                 dispatch_async(dispatch_get_main_queue(), ^{
                     
                     if (error) {
                         UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"视频保存失败" message:nil
                                                                        delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                         [alert show];
                     } else {
                         UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"视频保存成功" message:nil
                                                                        delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                         [alert show];
                     }
                 });
             }];
        }
        else {
            NSLog(@"error mssg)");
        }
    }];
}


// 更新进度
- (void)updateProgress
{
    self.mLabel.text = [NSString stringWithFormat:@"Progress:%d%%", (int)(movieFile.progress * 100)];
    [self.mLabel sizeToFit];
}

感谢http://www.jianshu.com/p/965df0f28014 真的是大神,膜拜
越学越会觉得自己的不足,趁年轻要更好的丰富自己,加油,生命不息,代码不止