视频取缩略图

///视频 获取 缩略图

- (UIImage*) thumbnailImageForVideo:(NSURL *)videoURL atTime:(NSTimeInterval)time {

    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil] ;

    NSParameterAssert(asset);

    AVAssetImageGenerator *assetImageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];

    assetImageGenerator.appliesPreferredTrackTransform = YES;

    assetImageGenerator.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels;

    //取帧

    CGImageRef thumbTemp = NULL;

    CMTime actualTime ;

    //    int32_t time = asset.duration.timescale;

    NSError *error = nil;

    thumbTemp = [assetImageGenerator copyCGImageAtTime:CMTimeMake(time, asset.duration.timescale) actualTime:&actualTime error:&error];

    NSLog(@"%lld",actualTime.value);

    UIImage *thumb = nil;

    if (!error)

    {

        thumb = [[UIImage alloc] initWithCGImage:thumbTemp];

    }

    CGImageRelease(thumbTemp);

    return thumb;

}