如何在现有视频中添加过滤器？

Question

我想在我现有的捕获的视频中添加滤镜效果，我试图用GPUImageMovie(<GPUImage/GPUImage.h>)来做到这一点，但碰到[movieWriter startRecording];，所以如果有任何其他适当的方式来做到这一点，请你给我建议。

在此先感谢。

Answer 1

只要通过您现有的videoURL，它将被过滤，不要忘记添加GPUImage框架。

- (void)testFilterOptions:(NSURL*)videoUrl{ 

    movieFile = [[GPUImageMovie alloc] initWithURL:videoUrl]; 
    movieFile.runBenchmark = YES; 
    movieFile.playAtActualSpeed = NO; 
    //filter = [[GPUImagePixellateFilter alloc] init]; 
    filter = [[GPUImageSepiaFilter alloc] init]; 

    [movieFile addTarget:filter]; 

    // Only rotate the video for display, leave orientation the same for recording 
// GPUImageView *filterView = (GPUImageView *)self.previewView; 
// [filter addTarget:filterView]; 

    // In addition to displaying to the screen, write out a processed version of the movie to disk 
    NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.mov"]; 
    unlink([pathToMovie UTF8String]); // If a file already exists, AVAssetWriter won't let you record new frames, so delete the old movie 
    NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie]; 

    movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(480.0, 480.0)]; 
    [filter addTarget:movieWriter]; 

    // Configure this for video from the movie file, where we want to preserve all video frames and audio samples 
    movieWriter.shouldPassthroughAudio = NO; 
    movieFile.audioEncodingTarget = nil; 
    [movieFile enableSynchronizedEncodingUsingMovieWriter:movieWriter]; 

    [movieWriter startRecording]; 
    [movieFile startProcessing]; 

    [movieWriter setCompletionBlock:^{ 
     [filter removeTarget:movieWriter]; 
     [movieWriter finishRecording]; 

     dispatch_async(dispatch_get_main_queue(), ^{ 
     //Recording complete do whatever you want 
     }); 
    }]; 
}