Uncaught TypeError: Cannot read property 'getTracks' of undefined

Question

The camera does not turn on. How to fix this problem

I tried it, but it did not

stop the webcam streaming of getUserMedia without page refreshing

LoadCam

function loadCam(stream) {
        try {
          this.srcObject = stream;
        } catch (error) {
          this.src = window.URL.createObjectURL(stream);
        }
        logger("Camera loaded [OKAY]");
        localstream = stream;
      }

Stop error

 if (--timer >= 0) {
            } else {
                clearInterval(faceStream);
                document.getElementById("face-login").style.display = 'inline-block';
                video.pause();
                video.src = "";
                localstream.getTracks()[0].stop();

                timer = duration;
                socket.emit("stream-end", '');
            }

You should put more code here, because based on what it is shown, it is not clear what is going on. The only thing for sure is that localstream = stream is not being called, or stream is undefined. — Lazar Nikolic, Nov 20 '19 at 12:17
So `localstream` is undefined. Impossible to answer why with the code provided. — epascarello, Nov 20 '19 at 13:36

score 0 · Answer 1 · answered Nov 21 '19 at 13:26

<script>
    var socket = io();
    function logger(msg) {
      $("#logger").text(msg);
    }

    function stream() {
      var canv = document.getElementById("prev"),
      context = canv.getContext("2d"),
      video = document.getElementById("video"),
      localstream,
      freq = 10;

      canv.width = 200;//window.innerWidth ;//  800;
      canv.height = 200;//window.innerHeight;// 400;

      context.width = canv.width;
      context.height = canv.height;

      function loadCam(stream) {
        try {
          this.srcObject = stream;
        } catch (error) {
          this.src = window.URL.createObjectURL(stream);
        }
        logger("Camera loaded [OKAY]");
        localstream = stream;
      }

      function loadFail(stream) {
        logger("Failed loading camera");
      }

      function viewVideo(video, context) {
        context.drawImage(video, 0, 0, context.width, context.height);
        socket.emit("stream", canv.toDataURL("image/webp"));
      }

      $(function() {
        navigator.getUserMedia = navigator.getUserMedia ||
                           navigator.webkitGetUserMedia ||
                           navigator.mozGetUserMedia;

        if(navigator.getUserMedia) {
          navigator.getUserMedia({video: true}, loadCam, loadFail);
        }

        var duration = 60 * 0.2;//
        var timer = duration, minutes, seconds;

        var faceStream = setInterval(function() {
          viewVideo(video, context);

          minutes = parseInt(timer / 60, 10)
          seconds = parseInt(timer % 60, 10);

          minutes = minutes < 10 ? "0" + minutes : minutes;
          seconds = seconds < 10 ? "0" + seconds : seconds;
            if (--timer >= 0) {
            } else {
                clearInterval(faceStream);
                document.getElementById("face-login").style.display = 'inline-block';
                video.pause();
                video.src = "";
                localstream.getTracks()[0].stop();
                timer = duration;
                socket.emit("stream-end", '');
            }
            logger("Recognizing in: " + minutes + ":" + seconds);
        }, freq*10);
      });
    }

    function view() {
      document.getElementById("face-login").style.display = 'none';

      stream();


      socket.on("stream", function (data) {
        var img = document.getElementById("img");
        img.style.display = 'block';
        img.src = data['img'];


        var devRect = document.getElementById("face-detect");
        var rect = data['rectFace'];
        if(Object.keys(rect).length !== 0) {
          devRect.style.display = 'block';
          devRect.style.top = rect.y + 'px';
          devRect.style.left = rect.x + 'px';
          devRect.style.width = rect.w + 'px';
          devRect.style.height = rect.h + 'px';

        } else {
          devRect.style.display = 'none';

        }
      });

      socket.on("stream-end", function (data) {
        $("#face-login").hide();
        $("#face-detect").hide();
        logger("Verifying user...");
        socket.emit("verify-user", '');
      });

      socket.on("verify-user", function (data) {
        $("#face-detect").hide();
        logger("verified, " + data['name'] + ", accouracy: " + data['accouracy']);
        console.log(data)
        if(data['id']) {
          $("#face-login").hide();
          $.post("/login", {'auth_key': data['auth_key']}, function(data) {
            location.reload();
          })
        } else {
          $("#face-login").show();
        }
      });
    }

  </script>

Please update this answer with some explanatory text. – Dominic Cerisano Apr 19 '23 at 18:00 — Dominic Cerisano, Apr 19 '23 at 18:00

Uncaught TypeError: Cannot read property 'getTracks' of undefined

1 Answers1