if ([SKYVideoAnalyser sharedInstance].analysing && self.analysisQueue.operationCount < (NSUInteger)self.analysisQueue.maxConcurrentOperationCount)
{
                            [self.analysisQueue addOperationWithBlock:^{
                                SKYYUVFrameSource* source = [SKYYUVFrameSource new];
                                source.frame = *(_renderYUVFrame[_renderFrameIndex]);
                                double seconds = [[NSDate new] timeIntervalSinceDate:[SKYVideoAnalyser sharedInstance].analysisStartTime];
                                NSLog(@"analysing time: %f", seconds);
                                [[SKYVideoAnalyser sharedInstance] analyzeFrame:source atTime:CMTimeMake(seconds * 1000, 1000) sequential:YES];
                            }];
                        }