closing debug file

filter/basic.go

@@ -42,18 +42,14 @@ import (
 	"golang.org/x/image/math/fixed"
 )
 
-const filename = "motion.mjpeg"
+const debugfile = "motion.mjpeg"
 
 const (
 	threshold = 45000
 	pixels    = 1000
 )
 
-type pixel struct {
-	r uint32
-	g uint32
-	b uint32
-}
+type pixel struct{ r, g, b uint32 }
 
 // BasicFilter is a filter that provides basic motion detection via a difference
 // method.
@@ -76,20 +72,19 @@ func NewBasicFilter(dst io.WriteCloser, debug bool) *Basic {
 	var err error
 	file = nil
 	if debug {
-		file, err = os.Create(filename)
+		file, err = os.Create(debugfile)
 		if err != nil {
 			panic(fmt.Sprintf("could not create debug file: %v", err))
 		}
-	} else {
-		file = nil
 	}
 	return &Basic{dst, nil, nil, bwImg, 0, 0, file, 0, debug}
 }
 
 // Implements io.Closer.
-// Close frees resources used by gocv, because it has to be done manually, due to
-// it using c-go.
 func (bf *Basic) Close() error {
+	if bf.debug {
+		bf.file.Close()
+	}
 	return nil
 }