README.md

Publishing with User-Selected Camera Source : WebRTC

This example demonstrates a request for a MediaStream with a defined video source for the constraint.

Please refer to the Basic Publisher Documentation to learn more about the basic setup.

Example Code

• index.html
• index.js

These examples use the WebRTC-based Publisher implementation from the Red5 Pro HTML SDK. However, there is failover support to allow for Flash-base publisher on unsupported browsers.

Camera Selection

Allow the User to select from a list of cameras detected by their browser. To access the list of camera devices, use the enumerateDevices API:

function listDevices (devices) {
  var cameras = devices.filter(function (item) {
    return item.kind === 'videoinput';
  })
  var options = cameras.map(function (camera, index) {
    return '<option value="' + camera.deviceId + '">' + (camera.label || 'camera ' + index) + '</option>';
  });
  cameraSelect.innerHTML = options.join(' ');
}

navigator.mediaDevices.enumerateDevices().then(listDevices).catch(onDeviceError);

index.js #189

The camera devices are filtered out from the list returned on enumerateDevices based on the kind attribute being of videoinput value. The list is then provided a a select element with an event handler assigned.

Upon a change event, the camera deviceId is used to assign the video constraint for the MediaStream.

Selection & Assignment

Constraints for the audio and video components are defined when accessing a MediaStream from the browser.

To define a stream with a specific camera device for publishing, update the video constraint used in requesting a MediaStream and declare a sourceId with the selected camera deviceId.

The following change event handler is invoked upon User selection of a camera from the select element populated in the previous section:

var mediaConstraints = {
  audio: configuration.useAudio ? configuration.mediaConstraints.audio : false,
  video: configuration.useVideo ? configuration.mediaConstraints.video : false,
};

function onCameraSelect () {
  if (!configuration.useVideo) {
    return;
  }
  var selection = cameraSelect.value;
  if (mediaConstraints.video && typeof mediaConstraints.video !== 'boolean') {
    mediaConstraints.video.deviceId = { exact: selection }
    delete mediaConstraints.video.frameRate
  }
  else {
    mediaConstraints.video = {
      deviceId: { exact: selection }
    };
  }
  updateStatistics(0, 0, 0, 0);
  statisticsField.classList.add('hidden');
  unpublish()
    .then(restart)
    .catch(function (error) {
      console.error('[Red5ProPublisher] :: Error in unpublishing - ' + error);
      restart();
     });
  publishButton.disabled = false;
}

Publishing

With the mediaConstraints object updated with the target camera, the initialization configuration is set to start a new publishing session using the onGetUserMedia override to ensure proper listing of devices and labels:

var config = Object.assign({},
              configuration,
              defaultConfiguration,
              getAuthenticationParams(),
              {
                onGetUserMedia: function () {
                  return new Promise(function (resolve, reject) {
                    if (targetPublisher && targetPublisher.getMediaStream()) {
                      targetPublisher.getMediaStream().getTracks().forEach(function(track) {
                        track.stop();
                      });
                    }
                    var stream;
                    var constraints = mediaConstraints;
                    navigator.mediaDevices.getUserMedia(constraints)
                      .then(function (mediastream) {
                        stream = mediastream;
                        return navigator.mediaDevices.enumerateDevices()
                      })
                      .then(function (devices) {
                        listDevices(devices);
                        stream.getVideoTracks().forEach(function (track) {
                          cameraSelect.value = track.getSettings().deviceId;
                        });
                        resolve(stream);
                      })
                      .catch(function (error) {
                        reject(error);
                      })
                  });
                }
              });

var rtcConfig = Object.assign({}, config, {
      protocol: getSocketLocationFromProtocol().protocol,
      port: getSocketLocationFromProtocol().port,
      streamName: config.stream1
   });
return new red5prosdk.RTCPublisher().init(rtcConfig);

index.js #213

More information: Media.getUserMedia from MDN