获取视频的第一帧

 1 +(UIImage *)getImage:(NSString *)videoURL
 2 {
 3     //视频地址
 4     NSURL *url = [[NSURL alloc] initWithString:videoURL];//initFileURLWithPath:videoURL] autorelease];
 5     
 6     AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:url options:nil];//
 7     //获取视频时长，单位：秒
 8     NSLog(@"%llu",urlAsset.duration.value/urlAsset.duration.timescale);
 9     
10     AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:urlAsset];
11     
12     generator.appliesPreferredTrackTransform = YES;
13     generator.maximumSize = CGSizeMake(1136, 640);
14     
15     NSError *error = nil;
16     CGImageRef img = [generator copyCGImageAtTime:CMTimeMake(0, 1) actualTime:NULL error:&error];
17     UIImage *image = [UIImage imageWithCGImage: img];
18     return image;
19 }