add go routine to write function

cmd/rv/main.go

@@ -195,15 +195,17 @@ func (tp *turbidityProbe) Write(p []byte) (int, error) {
 		tp.log.Log(logger.Debug, "found frames", "frames", len(imgs))
 
 		// Process video data to get saturation and contrast scores.
+		go func() {
 			startTime := time.Now()
 			res, err := tp.ts.Evaluate(imgs)
-		tp.log.Log(logger.Debug, "finished evaluation", "total duration (sec)", time.Since(startTime).Seconds())
 			if err != nil {
 				tp.log.Error("evaluate failed", "error", err.Error())
-			return len(p), err
-		}
+			} else {
+				tp.log.Log(logger.Debug, "finished evaluation", "total duration (sec)", time.Since(startTime).Seconds())
 				tp.contrast = stat.Mean(res.Contrast, nil)
 				tp.sharpness = stat.Mean(res.Sharpness, nil)
+			}
+		}()
 	default:
 		return len(p), nil
 	}