optimising

filter/basic.go

@@ -43,12 +43,21 @@ import (
 	"golang.org/x/image/math/fixed"
 )
 
+func absDiff(a, b uint32) int {
+	c := int(a) - int(b)
+	if c < 0 {
+		return -c
+	} else {
+		return c
+	}
+
+}
+
 // MOGFilter is a filter that provides basic motion detection. MoG is short for
 // Mixture of Gaussians method.
 type BasicFilter struct {
 	dst   io.WriteCloser
 	bg    [][][3]uint32
-	current [][][3]uint32
 	w     int
 	h     int
 	file  io.WriteCloser
@@ -68,7 +77,7 @@ func NewBasicFilter(dst io.WriteCloser, debug bool) *BasicFilter {
 		file = nil
 	}
 
-	return &BasicFilter{dst, nil, nil, 0, 0, file, debug}
+	return &BasicFilter{dst, nil, 0, 0, file, debug}
 }
 
 // Implements io.Closer.
@@ -82,7 +91,7 @@ func (m *BasicFilter) Close() error {
 // Write applies the motion filter to the video stream. Only frames with motion
 // are written to the destination encoder, frames without are discarded.
 func (b *BasicFilter) Write(f []byte) (int, error) {
-	//t0 := time.Now()
+	t0 := time.Now()
 	//decode MJPEG
 	r := bytes.NewReader(f)
 	img, err := jpeg.Decode(r)
@@ -103,20 +112,13 @@ func (b *BasicFilter) Write(f []byte) (int, error) {
 			b.bg[i] = make([][3]uint32, b.w)
 		}
 
-		b.current = make([][][3]uint32, b.h)
-		for i, _ := range b.current {
-			b.current[i] = make([][3]uint32, b.w)
-		}
-
 		for j := 0; j < b.h; j++ {
 			for i := 0; i < b.w; i++ {
 				n := img.At(i, j)
 				R, G, B, _ := n.RGBA()
-				b.bg[j][i] = [3]uint32{R, G, B}
+				copy(b.bg[j][i][:], []uint32{R, G, B})
 			}
 		}
-		t2 := time.Now()
-		fmt.Print("BG loop: ", t2.Sub(t1).Milliseconds(), "\n")
 		return len(f), nil
 	}
 
@@ -126,28 +128,49 @@ func (b *BasicFilter) Write(f []byte) (int, error) {
 	bwImg := image.NewRGBA(image.Rect(0, 0, b.w, b.h))
 	for j := 0; j < b.h; j++ {
 		for i := 0; i < b.w; i++ {
+			// ti0 := time.Now()
 			n := img.At(i, j)
+			// ti1 := time.Now()
 			R, G, B, _ := n.RGBA()
-			b.current[j][i] = [3]uint32{R, G, B}
+			// ti2 := time.Now()
-
-			diffR := R - b.bg[j][i][0]
-			diffG := G - b.bg[j][i][1]
-			diffB := B - b.bg[j][i][2]
-
 			// diffR := int(math.Abs(float64(R) - float64(b.bg[j][i][0])))
 			// diffG := int(math.Abs(float64(G) - float64(b.bg[j][i][1])))
 			// diffB := int(math.Abs(float64(B) - float64(b.bg[j][i][2])))
+
+			diffB := absDiff(B, b.bg[j][i][2])
+			diffR := absDiff(R, b.bg[j][i][0])
+			diffG := absDiff(G, b.bg[j][i][1])
+
+			// ti3 := time.Now()
+
 			diff := diffR + diffG + diffB
 
-			if diff < 45000 && b.debug {
+			if diff > 45000 {
-				bwImg.SetRGBA(i, j, color.RGBA{0x00, 0x00, 0x00, 0xff})
-			} else {
-				bwImg.SetRGBA(i, j, color.RGBA{0xff, 0xff, 0xff, 0xff})
 				motion++
 			}
+
+			if b.debug {
+				if diff > 45000 {
+					bwImg.SetRGBA(i, j, color.RGBA{0xff, 0xff, 0xff, 0xff})
+				} else {
+					bwImg.SetRGBA(i, j, color.RGBA{0x00, 0x00, 0x00, 0xff})
 				}
 			}
-	//t3 := time.Now()
+			// ti4 := time.Now()
+			// Update backgound image.
+			copy(b.bg[j][i][:], []uint32{R, G, B})
+			// ti5 := time.Now()
+
+			// fmt.Print("At: ", ti1.Sub(ti0).Nanoseconds(), "\n")
+			// fmt.Print("RGBA: ", ti2.Sub(ti1).Nanoseconds(), "\n")
+			// fmt.Print("3x absDiff: ", ti3.Sub(ti2).Nanoseconds(), "\n")
+			// fmt.Print("total diff + threshold + debug: ", ti4.Sub(ti3).Nanoseconds(), "\n")
+			// fmt.Print("update bg: ", ti5.Sub(ti4).Nanoseconds(), "\n")
+			// fmt.Print("Total: ", time.Now().Sub(ti0).Nanoseconds(), "\n\n")
+		}
+	}
+	t2 := time.Now()
+
 	//visualise
 	if b.debug {
 		col := color.RGBA{200, 100, 0, 255}
@@ -165,20 +188,19 @@ func (b *BasicFilter) Write(f []byte) (int, error) {
 			return len(f), err
 		}
 	}
-	//t4 := time.Now()
+	t3 := time.Now()
-	// //update backgound image
+
-	b.bg = b.current
+	fmt.Print("Encode: ", t1.Sub(t0).Milliseconds(), "\n")
-	//get mean of this difference
+	fmt.Print("Calc loop: ", t2.Sub(t1).Milliseconds(), "\n")
+	fmt.Print("VLC: ", t3.Sub(t2).Milliseconds(), "\n")
+	fmt.Print("Total: ", time.Now().Sub(t0).Milliseconds(), "\n\n")
 
 	//choose a threshold that motion is detected for if greater
-
+	if motion < 1000 {
+		return len(f), nil
+	}
 	//discard non motion frames
 
 	//write motion frames
-	// fmt.Print("Encode: ", t1.Sub(t0).Milliseconds(), "\n")
-	// fmt.Print("BG loop: ", t2.Sub(t1).Milliseconds(), "\n")
-	// fmt.Print("Calc loop: ", t3.Sub(t2).Milliseconds(), "\n")
-	// fmt.Print("VLC: ", t4.Sub(t3).Milliseconds(), "\n")
-	// fmt.Print("Total: ", time.Now().Sub(t0).Milliseconds(), "\n\n")
 	return b.dst.Write(f)
 }

filter/mog.go

@@ -33,7 +33,6 @@ import (
 	"image"
 	"image/color"
 	"io"
-	"time"
 
 	"gocv.io/x/gocv"
 )
@@ -79,7 +78,6 @@ func (m *MOGFilter) Close() error {
 // Write applies the motion filter to the video stream. Only frames with motion
 // are written to the destination encoder, frames without are discarded.
 func (m *MOGFilter) Write(f []byte) (int, error) {
-	t0 := time.Now()
 	if m.hfCount < (m.hf - 1) {
 		m.hold[m.hfCount] = f
 		m.hfCount++
@@ -136,9 +134,9 @@ func (m *MOGFilter) Write(f []byte) (int, error) {
 	}
 
 	// Don't write to destination if there is no motion.
-	// if len(contours) == 0 {
+	if len(contours) == 0 {
-	// 	return len(f), nil
+		return len(f), nil
-	// }
+	}
 
 	// Write to destination, past 4 frames then current frame.
 	for i, h := range m.hold {
@@ -148,6 +146,5 @@ func (m *MOGFilter) Write(f []byte) (int, error) {
 			return len(f), fmt.Errorf("could not write previous frames: %w", err)
 		}
 	}
-	fmt.Print(time.Now().Sub(t0).Milliseconds(), "\n")
 	return m.dst.Write(f)
 }