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我试图在顶部添加效果来编辑现有的电影,因此我需要能够扫描所有电影帧,将它们作为UIImage,应用效果,然后更新该帧或将其写入新电影.我发现人们建议使用AVAssetImageGenerator.以下是我最后编辑的样本:

-(void)processMovie:(NSString*)moviePath {
    NSURL* url = [NSURL fileURLWithPath:moviePath];
    AVURLAsset *asset=[[AVURLAsset alloc] initWithURL:url options:nil];
    float movieTimeInSeconds = CMTimeGetSeconds([movie duration]);
    AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    generator.requestedTimeToleranceBefore = generator.requestedTimeToleranceAfter = kCMTimeZero;
    generator.appliesPreferredTrackTransform=TRUE;
    [asset release];

    // building array of time with steps as 1/10th of second
    NSMutableArray* arr = [[[NSMutableArray alloc] init] retain];
    for(int i=0; i<movieTimeInSeconds*10; i++) {
        [arr addObject:[NSValue valueWithCMTime:CMTimeMake(i,10)]];
    }

    AVAssetImageGeneratorCompletionHandler handler = ^(CMTime requestedTime, CGImageRef im, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error){
        if (result == AVAssetImageGeneratorSucceeded) {
            UIImage* img = …