Webcam streaming over HTTP

mjpeg-streamer.go

package main

import (
	"flag"
	"fmt"
	"image"
	"image/color"
	"log"
	"net/http"
	"time"

	"github.com/hybridgroup/mjpeg"
	"gocv.io/x/gocv"
)

var (
	deviceID = flag.Int("device", 0, "Device ID")
	httpAddr = flag.String("http", "0.0.0.0:8080", "HTTP interface to stream on")
)

func main() {
	webcam, err := gocv.VideoCaptureDevice(*deviceID)
	if err != nil {
		log.Fatalf("error opening video capture device: %v: %v", *deviceID, err)
	}
	defer webcam.Close()

	webcam.Set(gocv.VideoCaptureFPS, 10.0)

	stream := mjpeg.NewStream()

	go func() {
		img := gocv.NewMat()
		defer img.Close()

		for {
			if ok := webcam.Read(img); !ok {
				log.Println("error reading from video capture device")
				return
			}
			if img.Empty() {
				continue
			}
			ts := time.Now().Format("2006-01-02 13:04:05.000")
			gocv.PutText(img, ts, image.Point{30, 30}, gocv.FontHersheyComplexSmall, 0.8, color.RGBA{0, 255, 0, 255}, 1)
			frame, err := gocv.IMEncode(gocv.JPEGFileExt, img)
			if err != nil {
				log.Printf("error encoding frame: %v", err)
				continue
			}
			stream.UpdateJPEG(frame)
		}
	}()

	fmt.Printf("Streaming on %v...", *httpAddr)

	http.Handle("/", stream)
	log.Fatal(http.ListenAndServe(*httpAddr, nil))
}