Merged in less-frames (pull request #343)

Less frames

Approved-by: Saxon Milton <saxon.milton@gmail.com>

filter/filters_circleci.go

@@ -32,7 +32,7 @@ import (
 )
 
 // NewMOGFilter returns a pointer to a new NoOp struct for testing purposes only.
-func NewMOGFilter(dst io.WriteCloser, area, threshold float64, history int, debug bool) *NoOp {
+func NewMOGFilter(dst io.WriteCloser, area, threshold float64, history int, debug bool, hf int) *NoOp {
 	return &NoOp{dst: dst}
 }
 

filter/mog.go

@@ -40,23 +40,26 @@ import (
 // MOGFilter is a filter that provides basic motion detection. MoG is short for
 // Mixture of Gaussians method.
 type MOGFilter struct {
-	dst     io.WriteCloser
+	dst     io.WriteCloser                 // Destination to which motion containing frames go.
-	area    float64
+	area    float64                        // The minimum area that a contour can be found in.
-	bs      *gocv.BackgroundSubtractorMOG2
+	bs      *gocv.BackgroundSubtractorMOG2 // Uses the MOG algorithm to find the difference between the current and background frame.
-	knl     gocv.Mat
+	knl     gocv.Mat                       // Matrix that is used for calculations.
-	debug   bool
+	debug   bool                           // If true then debug windows with the bounding boxes and difference will be shown on the screen.
-	windows []*gocv.Window
+	windows []*gocv.Window                 // Holds debug windows.
+	hold    [][]byte                       // Will hold all frames up to hf (so only every hf frame is motion detected).
+	hf      int                            // The number of frames to be held.
+	hfCount int                            // Counter for the hold array.
 }
 
 // NewMOGFilter returns a pointer to a new MOGFilter struct.
-func NewMOGFilter(dst io.WriteCloser, area, threshold float64, history int, debug bool) *MOGFilter {
+func NewMOGFilter(dst io.WriteCloser, area, threshold float64, history int, debug bool, hf int) *MOGFilter {
 	bs := gocv.NewBackgroundSubtractorMOG2WithParams(history, threshold, false)
 	k := gocv.GetStructuringElement(gocv.MorphRect, image.Pt(3, 3))
 	var windows []*gocv.Window
 	if debug {
 		windows = []*gocv.Window{gocv.NewWindow("MOG: Bounding boxes"), gocv.NewWindow("MOG: Motion")}
 	}
-	return &MOGFilter{dst, area, &bs, k, debug, windows}
+	return &MOGFilter{dst, area, &bs, k, debug, windows, make([][]byte, hf-1), hf, 0}
 }
 
 // Implements io.Closer.
@@ -75,6 +78,13 @@ 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) {
+	if m.hfCount < (m.hf - 1) {
+		m.hold[m.hfCount] = f
+		m.hfCount++
+		return len(f), nil
+	}
+
+	m.hfCount = 0
 	img, err := gocv.IMDecode(f, gocv.IMReadColor)
 	if err != nil {
 		return 0, fmt.Errorf("image can't be decoded: %w", err)
@@ -125,9 +135,16 @@ func (m *MOGFilter) Write(f []byte) (int, error) {
 
 	// Don't write to destination if there is no motion.
 	if len(contours) == 0 {
-		return 0, nil
+		return len(f), nil
 	}
 
-	// Write to destination.
+	// Write to destination, past 4 frames then current frame.
+	for i, h := range m.hold {
+		_, err := m.dst.Write(h)
+		m.hold[i] = nil
+		if err != nil {
+			return len(f), fmt.Errorf("could not write previous frames: %w", err)
+		}
+	}
 	return m.dst.Write(f)
 }

revid/config/config.go

@@ -85,6 +85,7 @@ const (
 	defaultClipDuration    = 0
 	defaultAudioInputCodec = codecutil.ADPCM
 	defaultPSITime         = 2
+	defaultMotionInterval  = 5
 
 	// Ring buffer defaults.
 	defaultRBMaxElements  = 10000
@@ -275,6 +276,7 @@ type Config struct {
 	HorizontalFlip bool  // HorizontalFlip flips video horizontally for Raspivid input.
 	VerticalFlip   bool  // VerticalFlip flips video vertically for Raspivid input.
 	Filters        []int // Defines the methods of filtering to be used in between lexing and encoding.
+	MotionInterval int   // Sets the number of frames that are held before the filter is used (on the nth frame)
 	PSITime        int   // Sets the time between a packet being sent.
 
 	// Ring buffer parameters.
@@ -328,6 +330,7 @@ var TypeData = map[string]string{
 	"MOGHistory":       "uint",
 	"MOGMinArea":       "float",
 	"MOGThreshold":     "float",
+	"MotionInterval":   "int",
 	"RBCapacity":       "uint",
 	"RBMaxElements":    "uint",
 	"RBWriteTimeout":   "uint",
@@ -462,6 +465,10 @@ func (c *Config) Validate() error {
 		c.Logger.Log(logger.Info, pkg+"PSITime bad or unset, defaulting", "PSITime", defaultPSITime)
 		c.PSITime = defaultPSITime
 	}
+	if c.MotionInterval <= 0 {
+		c.Logger.Log(logger.Info, pkg+"MotionInterval bad or unset, defaulting", "MotionInterval", defaultMotionInterval)
+		c.MotionInterval = defaultMotionInterval
+	}
 
 	if c.MinFPS <= 0 {
 		c.Logger.Log(logger.Info, pkg+"MinFPS bad or unset, defaulting", "MinFPS", defaultMinFPS)

revid/revid.go

@@ -63,6 +63,24 @@ const (
 	rtmpConnectionTimeout  = 10
 )
 
+// Motion filter parameters.
+const minFPS = 1.0
+
+// KNN specific parameters.
+const (
+	knnMinArea   = 25.0
+	knnThreshold = 300
+	knnHistory   = 300
+	knnKernel    = 9
+)
+
+// MOG specific parameters.
+const (
+	mogMinArea   = 50
+	mogThreshold = 100
+	mogHistory   = 100
+)
+
 const pkg = "revid: "
 
 type Logger interface {
@@ -337,11 +355,11 @@ func (r *Revid) setupPipeline(mtsEnc func(dst io.WriteCloser, rate float64) (io.
 			case config.FilterNoOp:
 				r.filters[i] = filter.NewNoOp(dst)
 			case config.FilterMOG:
-				r.filters[i] = filter.NewMOGFilter(dst, r.cfg.MOGMinArea, r.cfg.MOGThreshold, int(r.cfg.MOGHistory), r.cfg.ShowWindows)
+				r.filters[i] = filter.NewMOGFilter(dst, mogMinArea, mogThreshold, mogHistory, r.cfg.ShowWindows, r.cfg.MotionInterval)
 			case config.FilterVariableFPS:
-				r.filters[i] = filter.NewVariableFPSFilter(dst, r.cfg.MinFPS, filter.NewMOGFilter(dst, r.cfg.MOGMinArea, r.cfg.MOGThreshold, int(r.cfg.MOGHistory), r.cfg.ShowWindows))
+				r.filters[i] = filter.NewVariableFPSFilter(dst, minFPS, filter.NewMOGFilter(r.encoders, mogMinArea, mogThreshold, mogHistory, r.cfg.ShowWindows, r.cfg.MotionInterval))
 			case config.FilterKNN:
-				r.filters[i] = filter.NewKNNFilter(dst, r.cfg.KNNMinArea, r.cfg.KNNThreshold, int(r.cfg.KNNHistory), int(r.cfg.KNNKernel), r.cfg.ShowWindows)
+				r.filters[i] = filter.NewKNNFilter(dst, knnMinArea, knnThreshold, knnHistory, knnKernel, r.cfg.ShowWindows)
 			default:
 				panic("Undefined Filter")
 			}
@@ -671,6 +689,13 @@ func (r *Revid) Update(vars map[string]string) error {
 				}
 				r.cfg.Filters[i] = v
 			}
+		case "MotionInterval":
+			v, err := strconv.Atoi(value)
+			if err != nil || v < 0 {
+				r.cfg.Logger.Log(logger.Warning, pkg+"invalid MotionInterval var", "value", value)
+				break
+			}
+			r.cfg.MotionInterval = v
 		case "PSITime":
 			v, err := strconv.Atoi(value)
 			if err != nil || v < 0 {