getDuration() now overridden to return hlsjs reported duration

Also timeupdate event now always contains the actual time instead of
trying to round up to the duration when dvr wasn't being used
(incorrectly). I think the reason this was there was to make the seek
bar stick to the right when dvr wasn't being used but this might make
more sense being handled in MediaControl so that the correct values are
still reported in the event.

TODO:
- update MediaControl so that it renders the seek bar slider at the far
right when dvr is disabled.
- Figure out what do do in getPlayableStartTime() (See comment)

src/playbacks/hls/hls.js

@@ -15,7 +15,21 @@ export default class HLS extends HTML5VideoPlayback {
   get currentLevel() { return (this.hls && this.hls.currentLevel) || -1 }
   set currentLevel(level) { this.hls && (this.hls.currentLevel = level) }
 
+  // for hls streams which have dvr with a sliding window,
+  // the content at the start of the playlist is removed as new
+  // content is appended at the end.
+  // this means the actual playable start time will increase as the
+  // start content is deleted
+  // For streams with dvr where the entire recording is kept from the
+  // beginning this should always return 0
   getPlayableStartTime() {
+    // TODO this should probably just return video.seekable.start(0)
+    // but looks like this might have a bug/not been implemented at the moment
+    // https://github.com/dailymotion/hls.js/issues/65
+
+    // for now return this even though it's wrong as it works ok
+    // super.getDuration() should never be used for reasons
+    // described in https://github.com/clappr/clappr/issues/668#issuecomment-157036678
     return super.getDuration() - this.playableRegionDuration
   }
 
@@ -41,6 +55,13 @@ export default class HLS extends HTML5VideoPlayback {
     this.hls.attachVideo(this.el)
   }
 
+  // the duration on the video element itself should not be used
+  // as this does not necesarily represent the duration of the stream
+  // https://github.com/clappr/clappr/issues/668#issuecomment-157036678
+  getDuration() {
+    return this.playableRegionDuration
+  }
+
   getCurrentTime() {
     return this.el.currentTime - this.getPlayableStartTime()
   }
@@ -76,11 +97,7 @@ export default class HLS extends HTML5VideoPlayback {
   }
 
   timeUpdated() {
-    if (this.dvrEnabled) {
-      this.trigger(Events.PLAYBACK_TIMEUPDATE, this.dvrInUse ? this.getCurrentTime() : this.playableRegionDuration, this.playableRegionDuration, this.name)
-    } else {
-      super.timeUpdated()
-    }
+    this.trigger(Events.PLAYBACK_TIMEUPDATE, this.getCurrentTime(), this.getDuration(), this.name)
   }
 
   play() {