iOS获取视频的第一帧图片thumbnailImage

我们的思路是先获取视频的URL，然后初始化一个MPMoviePlayerController做工具，利用MPMoviePlayerController来拿图片，看具体代码如下：

- (void)imagePickerController:(UIImagePickerController *)picker   didFinishPickingMediaWithInfo:(NSDictionary *)info
{

NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType];

if (CFStringCompare ((__bridge CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo) {
NSURL *videoUrl=(NSURL*)[info objectForKey:UIImagePickerControllerMediaURL];
NSString *moviePath = [videoUrl path];
这里利用MPMoviePlayerController来获取
MPMoviePlayerController *player = [[MPMoviePlayerController alloc]initWithContentURL:videoUrl] ;
UIImage  *thumbnail = [player thumbnailImageAtTime:1.0 timeOption:MPMovieTimeOptionNearestKeyFrame];

imageV.image = thumbnail;
player = nil;//释放player

NSString *videoCacheDir = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches/UploadPhoto/"];
if (![[NSFileManager defaultManager] fileExistsAtPath:videoCacheDir]) {
[[NSFileManager defaultManager] createDirectoryAtPath:videoCacheDir withIntermediateDirectories:YES attributes:nil error:nil];
}
}
[self dismissViewControllerAnimated:YES completion:nil];

}