streamwatcher/main.go
2020-07-06 19:50:36 +00:00

152 lines
3.6 KiB
Go
Executable file

package main
import (
"crypto/sha256"
"encoding/base64"
"image"
"io/ioutil"
"log"
"net/http"
"os"
"path/filepath"
"text/template"
"time"
"gocv.io/x/gocv"
)
// StreamURL Unexported
type StreamURL struct {
URL string
}
func index(w http.ResponseWriter, r *http.Request) {
if r.FormValue("URL") == "" {
indexTemplate, err := template.ParseFiles(filepath.Join("templates", "index.html"))
if err != nil {
log.Fatal(err)
}
indexTemplate.Execute(w, nil)
return
}
streamURL := StreamURL{
URL: r.FormValue("URL"),
}
streamTemplate, err := template.ParseFiles(filepath.Join("templates", "stream.html"))
if err != nil {
log.Fatal(err)
}
streamTemplate.Execute(w, streamURL)
}
func stream(w http.ResponseWriter, r *http.Request) {
if r.FormValue("URL") == "" {
return
}
w.Header().Set("Content-Type", "image/jpeg")
URL := r.FormValue("URL")
img := getStreamInstant(URL)
go saveStreamInstant(URL, img)
streamDir := URLToBase64(URL)
streamStoreDir := filepath.Join(".", "streams", string(streamDir))
previousStreamInstantPath := filepath.Join(streamStoreDir, "previous.jpg")
if fileExists(previousStreamInstantPath) {
newMat := gocv.NewMat()
mat, err := gocv.IMDecode(img, gocv.IMReadColor)
if err != nil {
log.Fatal("Could not IMDecode img")
}
gocv.CvtColor(mat, &newMat, gocv.ColorBGRToGray)
gocv.GaussianBlur(newMat, &newMat, image.Point{X: 21, Y: 21}, 0, 0, gocv.BorderReflect)
previous := gocv.IMRead(previousStreamInstantPath, gocv.IMReadColor)
gocv.CvtColor(previous, &previous, gocv.ColorBGRToGray)
gocv.GaussianBlur(previous, &previous, image.Point{X: 21, Y: 21}, 0, 0, gocv.BorderReflect)
gocv.AbsDiff(previous, newMat, &newMat)
gocv.Threshold(newMat, &newMat, 25, 255, gocv.ThresholdBinary)
img, err = gocv.IMEncode(".jpg", newMat)
}
w.Write(img)
}
func getStreamInstant(URL string) []byte {
resp, err := http.Get(URL)
if err != nil {
log.Fatal(err)
}
img, err := ioutil.ReadAll(resp.Body)
defer resp.Body.Close()
return img
}
func saveStreamInstant(URL string, img []byte) {
streamDir := URLToBase64(URL)
streamStoreDir := filepath.Join(".", "streams", string(streamDir))
os.MkdirAll(streamStoreDir, os.ModePerm)
currentStreamInstantPath := filepath.Join(streamStoreDir, "current.jpg")
swap := fileExists(streamStoreDir)
if swap {
currentStreamInstantPath = filepath.Join(streamStoreDir, "next.jpg")
}
err := ioutil.WriteFile(currentStreamInstantPath, img, os.ModePerm)
if err != nil {
log.Fatal("Can't write latest stream instant.")
}
if swap {
previousStreamInstantPath := filepath.Join(streamStoreDir, "previous.jpg")
nextStreamInstantPath := currentStreamInstantPath
currentStreamInstantPath = filepath.Join(streamStoreDir, "current.jpg")
err = os.Rename(currentStreamInstantPath, previousStreamInstantPath)
err = os.Rename(nextStreamInstantPath, currentStreamInstantPath)
}
}
func listenAndServe() {
staticFileServer := http.FileServer(http.Dir("./static"))
http.Handle("/static/", http.StripPrefix("/static/", staticFileServer))
http.HandleFunc("/", index)
http.HandleFunc("/stream", stream)
log.Fatal(http.ListenAndServe(":8080", nil))
}
func backend() {
for {
time.Sleep(time.Second)
}
}
func main() {
go listenAndServe()
backend()
}
func fileExists(path string) bool {
_, err := os.Stat(path)
return !os.IsNotExist(err)
}
func URLToBase64(URL string) (hash string) {
h := sha256.New()
h.Write([]byte(URL))
return base64.URLEncoding.EncodeToString(h.Sum(nil))
}