add example for gocv

examples/opencv_test.go

@@ -0,0 +1,197 @@
+// +build gocv
+
+// uncomment line above for gocv examples
+
+package examples
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+	"io"
+	"log"
+	"testing"
+
+	ffmpeg "github.com/u2takey/ffmpeg-go"
+	"gocv.io/x/gocv"
+)
+
+// TestExampleOpenCvFaceDetect will: take a video as input => use opencv for face detection => draw box and show a window
+// This example depends on gocv and opencv, please refer: https://pkg.go.dev/gocv.io/x/gocv for installation.
+func TestExampleOpenCvFaceDetectWithVideo(t *testing.T) {
+	inputFile := "./sample_data/head-pose-face-detection-male-short.mp4"
+	xmlFile := "./sample_data/haarcascade_frontalface_default.xml"
+
+	w, h := getVideoSize(inputFile)
+	log.Println(w, h)
+
+	pr1, pw1 := io.Pipe()
+	readProcess(inputFile, pw1)
+	openCvProcess(xmlFile, pr1, w, h)
+	log.Println("Done")
+}
+
+func readProcess(infileName string, writer io.WriteCloser) {
+	log.Println("Starting ffmpeg process1")
+	go func() {
+		err := ffmpeg.Input(infileName).
+			Output("pipe:",
+				ffmpeg.KwArgs{
+					"format": "rawvideo", "pix_fmt": "rgb24",
+				}).
+			WithOutput(writer).
+			ErrorToStdOut().
+			Run()
+		log.Println("ffmpeg process1 done")
+		_ = writer.Close()
+		if err != nil {
+			panic(err)
+		}
+	}()
+	return
+}
+
+func openCvProcess(xmlFile string, reader io.ReadCloser, w, h int) {
+	// open display window
+	window := gocv.NewWindow("Face Detect")
+	defer window.Close()
+
+	// color for the rect when faces detected
+	blue := color.RGBA{B: 255}
+
+	classifier := gocv.NewCascadeClassifier()
+	defer classifier.Close()
+
+	if !classifier.Load(xmlFile) {
+		fmt.Printf("Error reading cascade file: %v\n", xmlFile)
+		return
+	}
+
+	frameSize := w * h * 3
+	buf := make([]byte, frameSize, frameSize)
+	for {
+		n, err := io.ReadFull(reader, buf)
+		if n == 0 || err == io.EOF {
+			return
+		} else if n != frameSize || err != nil {
+			panic(fmt.Sprintf("read error: %d, %s", n, err))
+		}
+		img, err := gocv.NewMatFromBytes(h, w, gocv.MatTypeCV8UC3, buf)
+		if err != nil {
+			fmt.Println("decode fail", err)
+		}
+		if img.Empty() {
+			continue
+		}
+		img2 := gocv.NewMat()
+		gocv.CvtColor(img, &img2, gocv.ColorBGRToRGB)
+
+		// detect faces
+		rects := classifier.DetectMultiScale(img2)
+		fmt.Printf("found %d faces\n", len(rects))
+
+		// draw a rectangle around each face on the original image, along with text identifing as "Human"
+		for _, r := range rects {
+			gocv.Rectangle(&img2, r, blue, 3)
+
+			size := gocv.GetTextSize("Human", gocv.FontHersheyPlain, 1.2, 2)
+			pt := image.Pt(r.Min.X+(r.Min.X/2)-(size.X/2), r.Min.Y-2)
+			gocv.PutText(&img2, "Human", pt, gocv.FontHersheyPlain, 1.2, blue, 2)
+		}
+
+		// show the image in the window, and wait 1 millisecond
+		window.IMShow(img2)
+		img.Close()
+		img2.Close()
+		if window.WaitKey(10) >= 0 {
+			break
+		}
+	}
+	return
+}
+
+// TestExampleOpenCvFaceDetectWithCamera will: task stream from webcam => use opencv for face detection => output with ffmpeg
+// This example depends on gocv and opencv, please refer: https://pkg.go.dev/gocv.io/x/gocv for installation.
+func TestExampleOpenCvFaceDetectWithCamera(t *testing.T) {
+	deviceID := "0" // camera device id
+	xmlFile := "./sample_data/haarcascade_frontalface_default.xml"
+
+	webcam, err := gocv.OpenVideoCapture(deviceID)
+	if err != nil {
+		fmt.Printf("error opening video capture device: %v\n", deviceID)
+		return
+	}
+	defer webcam.Close()
+
+	// prepare image matrix
+	img := gocv.NewMat()
+	defer img.Close()
+
+	if ok := webcam.Read(&img); !ok {
+		panic(fmt.Sprintf("Cannot read device %v", deviceID))
+	}
+	fmt.Printf("img: %vX%v\n", img.Cols(), img.Rows())
+
+	pr1, pw1 := io.Pipe()
+	writeProcess("./sample_data/face_detect.mp4", pr1, img.Cols(), img.Rows())
+
+	// color for the rect when faces detected
+	blue := color.RGBA{B: 255}
+
+	// load classifier to recognize faces
+	classifier := gocv.NewCascadeClassifier()
+	defer classifier.Close()
+
+	if !classifier.Load(xmlFile) {
+		fmt.Printf("Error reading cascade file: %v\n", xmlFile)
+		return
+	}
+
+	fmt.Printf("Start reading device: %v\n", deviceID)
+	for i := 0; i < 200; i++ {
+		if ok := webcam.Read(&img); !ok {
+			fmt.Printf("Device closed: %v\n", deviceID)
+			return
+		}
+		if img.Empty() {
+			continue
+		}
+
+		// detect faces
+		rects := classifier.DetectMultiScale(img)
+		fmt.Printf("found %d faces\n", len(rects))
+
+		// draw a rectangle around each face on the original image, along with text identifing as "Human"
+		for _, r := range rects {
+			gocv.Rectangle(&img, r, blue, 3)
+
+			size := gocv.GetTextSize("Human", gocv.FontHersheyPlain, 1.2, 2)
+			pt := image.Pt(r.Min.X+(r.Min.X/2)-(size.X/2), r.Min.Y-2)
+			gocv.PutText(&img, "Human", pt, gocv.FontHersheyPlain, 1.2, blue, 2)
+		}
+		pw1.Write(img.ToBytes())
+	}
+	pw1.Close()
+	log.Println("Done")
+}
+
+func writeProcess(outputFile string, reader io.ReadCloser, w, h int) {
+	log.Println("Starting ffmpeg process1")
+	go func() {
+		err := ffmpeg.Input("pipe:",
+			ffmpeg.KwArgs{"format": "rawvideo",
+				"pix_fmt": "bgr24", "s": fmt.Sprintf("%dx%d", w, h),
+			}).
+			Overlay(ffmpeg.Input("./sample_data/overlay.png"), "").
+			Output(outputFile).
+			WithInput(reader).
+			ErrorToStdOut().
+			OverWriteOutput().
+			Run()
+		log.Println("ffmpeg process1 done")
+		if err != nil {
+			panic(err)
+		}
+		_ = reader.Close()
+	}()
+}