Stop calling pause() before play promise resolved

scripts/html5.js

@@ -414,20 +414,31 @@ H5P.VideoHtml5 = (function ($) {
             self.seek(currentTimeBeforeChangingQuality);
           }
 
-          // Always play to get image.
-          video.play();
+          // Callback to resolve play
+          var resolvePlaying = function () {
+            if (stateBeforeChangingQuality !== H5P.Video.PLAYING) {
+              // Do not resume playing
+              video.pause();
+            }
 
-          if (stateBeforeChangingQuality !== H5P.Video.PLAYING) {
-            // Do not resume playing
-            video.pause();
-          }
+            // Done changing quality
+            stateBeforeChangingQuality = undefined;
 
-          // Done changing quality
-          stateBeforeChangingQuality = undefined;
+            // Remove any errors
+            if ($error.is(':visible')) {
+              $error.remove();
+            }
+          };
 
-          // Remove any errors
-          if ($error.is(':visible')) {
-            $error.remove();
+          // Always play to get image.
+          var playPromise = video.play();
+          if (playPromise !== undefined) {
+            playPromise.finally(() => {
+              resolvePlaying();
+            });
+          }
+          else {
+            resolvePlaying(); // Fallback
           }
         };
         video.addEventListener('loadedmetadata', loaded, false);
@@ -489,6 +500,22 @@ H5P.VideoHtml5 = (function ($) {
      * @param {Number} time
      */
     self.seek = function (time) {
+      if (lastState === undefined) {
+        // Make sure we always play before we seek to get an image.
+        // If not iOS devices will reset currentTime when pressing play.
+
+        // Always play to get image.
+        var playPromise = video.play();
+        if (playPromise !== undefined) {
+          playPromise.finally(() => {
+            video.pause();
+          });
+        }
+        else {
+          video.pause(); // Fallback
+        }
+      }
+
       video.currentTime = time;
       // Use canplaythrough for IOs devices
       // Use loadedmetadata for all other devices.