Ensure overlapping buffered edges are not interpreted as updates

If the old and new buffered ranges have a shared start or end point, that edge should not be interpreted as a new buffered boundary. Fix up a number of the tests. Some tests are still failing.

@@ -187,20 +187,20 @@
        * active media playlist. When called with a single argument,
        * triggers the playlist loader to asynchronously switch to the
        * specified media playlist. Calling this method while the
-       * loader is in the HAVE_NOTHING or HAVE_MASTER states causes an
-       * error to be emitted but otherwise has no effect.
+       * loader is in the HAVE_NOTHING causes an error to be emitted
+       * but otherwise has no effect.
        * @param playlist (optional) {object} the parsed media playlist
        * object to switch to
        */
       loader.media = function(playlist) {
-        var mediaChange = false;
+        var startingState = loader.state, mediaChange;
         // getter
         if (!playlist) {
           return loader.media_;
         }
 
         // setter
-        if (loader.state === 'HAVE_NOTHING' || loader.state === 'HAVE_MASTER') {
+        if (loader.state === 'HAVE_NOTHING') {
           throw new Error('Cannot switch media playlist from ' + loader.state);
         }
 
@@ -213,7 +213,7 @@
           playlist = loader.master.playlists[playlist];
         }
 
-        mediaChange = playlist.uri !== loader.media_.uri;
+        mediaChange = !loader.media_ || playlist.uri !== loader.media_.uri;
 
         // switch to fully loaded playlists immediately
         if (loader.master.playlists[playlist.uri].endList) {
@@ -258,7 +258,17 @@
           withCredentials: withCredentials
         }, function(error, request) {
           haveMetadata(error, request, playlist.uri);
-          loader.trigger('mediachange');
+
+          if (error) {
+            return;
+          }
+
+          // fire loadedmetadata the first time a media playlist is loaded
+          if (startingState === 'HAVE_MASTER') {
+            loader.trigger('loadedmetadata');
+          } else {
+            loader.trigger('mediachange');
+          }
         });
       };
 
@@ -320,19 +330,13 @@
             loader.master.playlists[loader.master.playlists[i].uri] = loader.master.playlists[i];
           }
 
-          request = xhr({
-            uri: resolveUrl(srcUrl, parser.manifest.playlists[0].uri),
-            withCredentials: withCredentials
-          }, function(error, request) {
-            // pass along the URL specified in the master playlist
-            haveMetadata(error,
-                         request,
-                         parser.manifest.playlists[0].uri);
-            if (!error) {
-              loader.trigger('loadedmetadata');
-            }
-          });
-          return loader.trigger('loadedplaylist');
+          loader.trigger('loadedplaylist');
+          if (!request) {
+            // no media playlist was specifically selected so start
+            // from the first listed one
+            loader.media(parser.manifest.playlists[0]);
+          }
+          return;
         }
 
         // loaded a media playlist
@@ -468,8 +472,8 @@
     }
 
     // the playback position is outside the range of available
-    // segments so return the last one
-    return this.media_.segments.length - 1;
+    // segments so return the length
+    return this.media_.segments.length;
   };
 
   videojs.Hls.PlaylistLoader = PlaylistLoader;

@@ -190,7 +190,8 @@ videojs.Hls.prototype.src = function(src) {
     var updatedPlaylist = this.playlists.media();
 
     if (!updatedPlaylist) {
-      // do nothing before an initial media playlist has been activated
+      // select the initial variant
+      this.playlists.media(this.selectPlaylist());
       return;
     }
 
@@ -254,7 +255,7 @@ videojs.Hls.prototype.handleSourceOpen = function() {
 
 // Returns the array of time range edge objects that were additively
 // modified between two TimeRanges.
-var bufferedAdditions = function(original, update) {
+videojs.Hls.bufferedAdditions_ = function(original, update) {
   var result = [], edges = [],
       i, inOriginalRanges;
 
@@ -271,6 +272,15 @@ var bufferedAdditions = function(original, update) {
     var leftTime, rightTime;
     leftTime = left.start !== undefined ? left.start : left.end;
     rightTime = right.start !== undefined ? right.start : right.end;
+
+    // when two times are equal, ensure the original edge covers the
+    // update
+    if (leftTime === rightTime) {
+      if (left.original) {
+        return left.start !== undefined ? -1 : 1;
+      }
+      return right.start !== undefined ? -1 : 1;
+    }
     return leftTime - rightTime;
   });
 
@@ -349,8 +359,8 @@ videojs.Hls.prototype.setupSourceBuffer_ = function() {
     // annotate the segment with any start and end time information
     // added by the media processing
     segment = segmentInfo.playlist.segments[segmentInfo.mediaIndex];
-    timelineUpdates = bufferedAdditions(segmentInfo.buffered,
-                                        this.tech_.buffered());
+    timelineUpdates = videojs.Hls.bufferedAdditions_(segmentInfo.buffered,
+                                                     this.tech_.buffered());
     timelineUpdates.forEach(function(update) {
       if (update.start !== undefined) {
         segment.start = update.start;
@@ -1112,15 +1122,16 @@ videojs.Hls.prototype.drainBuffer = function(event) {
     this.sourceBuffer.timestampOffset = currentBuffered.end(0);
   }
 
-  // the segment is asynchronously added to the current buffered data
   if (currentBuffered.length) {
-    this.sourceBuffer.videoBuffer_.appendWindowStart = Math.min(this.tech_.currentTime(), currentBuffered.end(0));
-  } else if (this.sourceBuffer.videoBuffer_) {
-    this.sourceBuffer.videoBuffer_.appendWindowStart = 0;
+    // Chrome 45 stalls if appends overlap the playhead
+    this.sourceBuffer.appendWindowStart = Math.min(this.tech_.currentTime(), currentBuffered.end(0));
+  } else {
+    this.sourceBuffer.appendWindowStart = 0;
   }
   this.pendingSegment_ = segmentBuffer.shift();
   this.pendingSegment_.buffered = this.tech_.buffered();
 
+  // the segment is asynchronously added to the current buffered data
   this.sourceBuffer.appendBuffer(bytes);
 };
 

@@ -69,13 +69,16 @@
   });
 
   test('moves to HAVE_MASTER after loading a master playlist', function() {
-    var loader = new videojs.Hls.PlaylistLoader('master.m3u8');
+    var loader = new videojs.Hls.PlaylistLoader('master.m3u8'), state;
+    loader.on('loadedplaylist', function() {
+      state = loader.state;
+    });
     requests.pop().respond(200, null,
                            '#EXTM3U\n' +
                            '#EXT-X-STREAM-INF:\n' +
                            'media.m3u8\n');
     ok(loader.master, 'the master playlist is available');
-    strictEqual(loader.state, 'HAVE_MASTER', 'the state is correct');
+    strictEqual(state, 'HAVE_MASTER', 'the state at loadedplaylist correct');
   });
 
   test('jumps to HAVE_METADATA when initialized with a media playlist', function() {
@@ -453,6 +456,20 @@
                 'updated the active media');
   });
 
+  test('can switch playlists immediately after the master is downloaded', function() {
+    var loader = new videojs.Hls.PlaylistLoader('master.m3u8');
+    loader.on('loadedplaylist', function() {
+      loader.media('high.m3u8');
+    });
+    requests.pop().respond(200, null,
+                           '#EXTM3U\n' +
+                           '#EXT-X-STREAM-INF:BANDWIDTH=1\n' +
+                           'low.m3u8\n' +
+                           '#EXT-X-STREAM-INF:BANDWIDTH=2\n' +
+                           'high.m3u8\n');
+    equal(requests[0].url, urlTo('high.m3u8'), 'switched variants immediately');
+  });
+
   test('can switch media playlists based on URI', function() {
     var loader = new videojs.Hls.PlaylistLoader('master.m3u8');
     requests.pop().respond(200, null,
@@ -624,9 +641,6 @@
                            'low.m3u8\n' +
                            '#EXT-X-STREAM-INF:BANDWIDTH=2\n' +
                            'high.m3u8\n');
-    throws(function() {
-      loader.media('high.m3u8');
-    }, 'throws an error from HAVE_MASTER');
   });
 
   test('throws an error if a switch to an unrecognized playlist is requested', function() {
@@ -757,10 +771,8 @@
                              '#EXTINF:5,\n' +
                              '1.ts\n' +
                              '#EXT-X-ENDLIST\n');
-    equal(loader.getMediaIndexForTime_(4), 0, 'rounds down exact matches');
+    equal(loader.getMediaIndexForTime_(4), 1, 'rounds up exact matches');
     equal(loader.getMediaIndexForTime_(3.7), 0, 'rounds down');
-    // FIXME: the test below should pass for HLSv3
-    //equal(loader.getMediaIndexForTime_(4.2), 0, 'rounds down');
     equal(loader.getMediaIndexForTime_(4.5), 1, 'rounds up at 0.5');
   });
 

@@ -686,73 +686,59 @@ test('downloads media playlists after loading the master', function() {
   });
   openMediaSource(player);
 
-  // set bandwidth to an appropriate number so we don't switch
-  player.tech_.hls.bandwidth = 200000;
+  player.tech_.hls.bandwidth = 20e10;
   standardXHRResponse(requests[0]);
   standardXHRResponse(requests[1]);
   standardXHRResponse(requests[2]);
 
   strictEqual(requests[0].url, 'manifest/master.m3u8', 'master playlist requested');
   strictEqual(requests[1].url,
-              absoluteUrl('manifest/media.m3u8'),
+              absoluteUrl('manifest/media3.m3u8'),
               'media playlist requested');
   strictEqual(requests[2].url,
-              absoluteUrl('manifest/media-00001.ts'),
+              absoluteUrl('manifest/media3-00001.ts'),
               'first segment requested');
 });
 
-test('upshift if initial bandwidth is high', function() {
+test('upshifts if the initial bandwidth hint is high', function() {
   player.src({
     src: 'manifest/master.m3u8',
     type: 'application/vnd.apple.mpegurl'
   });
   openMediaSource(player);
 
+  player.tech_.hls.bandwidth = 10e20;
   standardXHRResponse(requests[0]);
-
-  player.tech_.hls.playlists.setBandwidth = function() {
-    player.tech_.hls.playlists.bandwidth = 1000000000;
-  };
-
   standardXHRResponse(requests[1]);
   standardXHRResponse(requests[2]);
 
-  standardXHRResponse(requests[3]);
-
   strictEqual(requests[0].url, 'manifest/master.m3u8', 'master playlist requested');
   strictEqual(requests[1].url,
-              absoluteUrl('manifest/media.m3u8'),
-              'media playlist requested');
-  strictEqual(requests[2].url,
               absoluteUrl('manifest/media3.m3u8'),
               'media playlist requested');
-  strictEqual(requests[3].url,
+  strictEqual(requests[2].url,
               absoluteUrl('manifest/media3-00001.ts'),
               'first segment requested');
 });
 
-test('dont downshift if bandwidth is low', function() {
+test('downshifts if the initial bandwidth hint is low', function() {
   player.src({
     src: 'manifest/master.m3u8',
     type: 'application/vnd.apple.mpegurl'
   });
   openMediaSource(player);
 
+  player.tech_.hls.bandwidth = 100;
   standardXHRResponse(requests[0]);
-
-  player.tech_.hls.playlists.setBandwidth = function() {
-    player.tech_.hls.playlists.bandwidth = 100;
-  };
-
   standardXHRResponse(requests[1]);
   standardXHRResponse(requests[2]);
 
   strictEqual(requests[0].url, 'manifest/master.m3u8', 'master playlist requested');
   strictEqual(requests[1].url,
-              absoluteUrl('manifest/media.m3u8'),
+              absoluteUrl('manifest/media1.m3u8'),
               'media playlist requested');
   strictEqual(requests[2].url,
-              absoluteUrl('manifest/media-00001.ts'),
+              absoluteUrl('manifest/media1-00001.ts'),
               'first segment requested');
 });
 
@@ -822,7 +808,7 @@ test('buffer checks are noops when only the master is ready', function() {
 
   strictEqual(1, requests.length, 'one request was made');
   strictEqual(requests[0].url,
-              absoluteUrl('manifest/media.m3u8'),
+              absoluteUrl('manifest/media1.m3u8'),
               'media playlist requested');
 });
 
@@ -876,11 +862,9 @@ test('selects a playlist after segment downloads', function() {
     return player.tech_.hls.playlists.master.playlists[0];
   };
 
-  standardXHRResponse(requests[0]);
-
-  player.tech_.hls.bandwidth = 3000000;
-  standardXHRResponse(requests[1]);
-  standardXHRResponse(requests[2]);
+  standardXHRResponse(requests[0]); // master
+  standardXHRResponse(requests[1]); // media
+  standardXHRResponse(requests[2]); // segment
 
   strictEqual(calls, 2, 'selects after the initial segment');
   player.currentTime = function() {
@@ -889,6 +873,7 @@ test('selects a playlist after segment downloads', function() {
   player.buffered = function() {
     return videojs.createTimeRange(0, 2);
   };
+  player.tech_.hls.sourceBuffer.trigger('updateend');
   player.tech_.hls.checkBuffer_();
 
   standardXHRResponse(requests[3]);
@@ -896,9 +881,7 @@ test('selects a playlist after segment downloads', function() {
   strictEqual(calls, 3, 'selects after additional segments');
 });
 
-test('moves to the next segment if there is a network error', function() {
-  var mediaIndex;
-
+test('reports an error if a segment is unreachable', function() {
   player.src({
     src: 'manifest/master.m3u8',
     type: 'application/vnd.apple.mpegurl'
@@ -909,62 +892,8 @@ test('moves to the next segment if there is a network error', function() {
   standardXHRResponse(requests[0]);
   standardXHRResponse(requests[1]);
 
-  mediaIndex = player.tech_.hls.mediaIndex;
-  player.trigger('timeupdate');
-
   requests[2].respond(400);
-  strictEqual(mediaIndex + 1, player.tech_.hls.mediaIndex, 'media index is incremented');
-});
-
-test('updates playlist timeline offsets if it detects a desynchronization', function() {
-  var buffered = [], currentTime = 0;
-
-  player.src({
-    src: 'manifest/master.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-  openMediaSource(player);
-  standardXHRResponse(requests.shift()); // master
-  requests.shift().respond(200, null,
-                           '#EXTM3U\n' +
-                           '#EXT-X-MEDIA-SEQUENCE:2\n' +
-                           '#EXTINF:10,\n' +
-                           '2.ts\n' +
-                           '#EXTINF:10,\n' +
-                           '3.ts\n'); // media
-  player.tech_.buffered = function() { return videojs.createTimeRange(buffered); };
-  player.tech_.currentTime = function() { return currentTime; };
-  player.tech_.paused = function() { return false; };
-  player.tech_.trigger('play');
-  clock.tick(1);
-  standardXHRResponse(requests.shift()); // segment 0
-  equal(player.tech_.hls.mediaIndex, 1, 'incremented mediaIndex');
-
-  player.tech_.hls.sourceBuffer.trigger('updateend');
-  buffered.push([0, 10]);
-
-  // force a playlist switch
-  player.tech_.hls.playlists.media('media1.m3u8');
-  requests = requests.filter(function(request) {
-    return !request.aborted;
-  });
-  requests.shift().respond(200, null,
-                           '#EXTM3U\n' +
-                           '#EXT-X-MEDIA-SEQUENCE:9999\n' +
-                           '#EXTINF:10,\n' +
-                           '3.ts\n' +
-                           '#EXTINF:10,\n' +
-                           '4.ts\n' +
-                           '#EXTINF:10,\n' +
-                           '5.ts\n'); // media1
-  player.tech_.hls.checkBuffer_();
-  standardXHRResponse(requests.shift());
-
-  buffered.push([20, 30]);
-  currentTime = 8;
-
-  player.tech_.hls.sourceBuffer.trigger('updateend');
-  equal(player.tech_.hls.mediaIndex, 0, 'prepared to request the missing segment');
+  strictEqual(player.tech_.hls.mediaSource.error_, 'network', 'network error is triggered');
 });
 
 test('updates the duration after switching playlists', function() {
@@ -974,19 +903,22 @@ test('updates the duration after switching playlists', function() {
     type: 'application/vnd.apple.mpegurl'
   });
   openMediaSource(player);
+
+  player.tech_.hls.bandwidth = 1e20;
+  standardXHRResponse(requests[0]); // master
+  standardXHRResponse(requests[1]); // media3
+
   player.tech_.hls.selectPlaylist = function() {
     selectedPlaylist = true;
 
-    // this duraiton should be overwritten by the playlist change
+    // this duration should be overwritten by the playlist change
     player.tech_.hls.mediaSource.duration = -Infinity;
 
     return player.tech_.hls.playlists.master.playlists[1];
   };
 
-  standardXHRResponse(requests[0]);
-  standardXHRResponse(requests[1]);
-  standardXHRResponse(requests[2]);
-  standardXHRResponse(requests[3]);
+  standardXHRResponse(requests[2]); // segment 0
+  standardXHRResponse(requests[3]); // media1
   ok(selectedPlaylist, 'selected playlist');
   ok(player.tech_.hls.mediaSource.duration !== -Infinity, 'updates the duration');
 });
@@ -1058,21 +990,6 @@ test('selects a playlist below the current bandwidth', function() {
               'the low bitrate stream is selected');
 });
 
-test('scales the bandwidth estimate for the first segment', function() {
-  player.src({
-    src: 'manifest/master.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-  openMediaSource(player);
-
-  requests[0].bandwidth = 500;
-  requests.shift().respond(200, null,
-                           '#EXTM3U\n' +
-                           '#EXT-X-PLAYLIST-TYPE:VOD\n' +
-                           '#EXT-X-TARGETDURATION:10\n');
-  equal(player.tech_.hls.bandwidth, 500 * 5, 'scaled the bandwidth estimate by 5');
-});
-
 test('allows initial bandwidth to be provided', function() {
   player.src({
     src: 'manifest/master.m3u8',
@@ -1242,6 +1159,7 @@ test('downloads the next segment if the buffer is getting low', function() {
   player.tech_.buffered = function() {
     return videojs.createTimeRange(0, 19.999);
   };
+  player.tech_.hls.sourceBuffer.trigger('updateend');
   player.tech_.hls.checkBuffer_();
 
   standardXHRResponse(requests[2]);
@@ -1253,8 +1171,12 @@ test('downloads the next segment if the buffer is getting low', function() {
 });
 
 test('buffers based on the correct TimeRange if multiple ranges exist', function() {
+  var currentTime, buffered;
   player.tech_.currentTime = function() {
-    return 8;
+    return currentTime;
+  };
+  player.tech_.buffered = function() {
+    return videojs.createTimeRange(buffered);
   };
 
   player.src({
@@ -1262,37 +1184,28 @@ test('buffers based on the correct TimeRange if multiple ranges exist', function
     type: 'application/vnd.apple.mpegurl'
   });
   openMediaSource(player);
-  player.tech_.buffered = function() {
-    return videojs.createTimeRange([[0, 10], [50, 160]]);
-  };
+  currentTime = 8;
+  buffered = [[0, 10], [20, 40]];
 
   standardXHRResponse(requests[0]);
   standardXHRResponse(requests[1]);
 
   strictEqual(requests.length, 2, 'made two requests');
   strictEqual(requests[1].url,
-              absoluteUrl('manifest/media-00001.ts'),
+              absoluteUrl('manifest/media-00002.ts'),
               'made segment request');
 
-  player.tech_.currentTime = function() {
-    return 55;
-  };
-
+  currentTime = 22;
+  player.tech_.hls.sourceBuffer.trigger('updateend');
   player.tech_.hls.checkBuffer_();
-
   strictEqual(requests.length, 2, 'made no additional requests');
 
-  player.tech_.currentTime = function() {
-    return 134;
-  };
-
+  buffered = [[0, 10], [20, 30]];
   player.tech_.hls.checkBuffer_();
   standardXHRResponse(requests[2]);
-
   strictEqual(requests.length, 3, 'made three requests');
-
   strictEqual(requests[2].url,
-              absoluteUrl('manifest/media-00002.ts'),
+              absoluteUrl('manifest/media-00004.ts'),
               'made segment request');
 });
 
@@ -1334,15 +1247,8 @@ test('only appends one segment at a time', function() {
   standardXHRResponse(requests.pop()); // media.m3u8
   standardXHRResponse(requests.pop()); // segment 0
 
-  player.tech_.hls.sourceBuffer.updating = true;
-  player.tech_.hls.sourceBuffer.appendBuffer = function() {
-    appends++;
-  };
-
   player.tech_.hls.checkBuffer_();
-  standardXHRResponse(requests.pop()); // segment 1
-  player.tech_.hls.checkBuffer_(); // should be a no-op
-  equal(appends, 0, 'did not append while updating');
+  equal(requests.length, 0, 'did not request while updating');
 });
 
 QUnit.skip('records the min and max PTS values for a segment', function() {
@@ -1424,7 +1330,6 @@ QUnit.skip('records PTS values for audio-only segments', function() {
 });
 
 test('waits to download new segments until the media playlist is stable', function() {
-  var media;
   player.src({
     src: 'manifest/master.m3u8',
     type: 'application/vnd.apple.mpegurl'
@@ -1432,22 +1337,19 @@ test('waits to download new segments until the media playlist is stable', functi
   openMediaSource(player);
   standardXHRResponse(requests.shift()); // master
   player.tech_.hls.bandwidth = 1; // make sure we stay on the lowest variant
-  standardXHRResponse(requests.shift()); // media
+  standardXHRResponse(requests.shift()); // media1
 
-  // mock a playlist switch
-  media = player.tech_.hls.playlists.media();
-  player.tech_.hls.playlists.media = function() {
-    return media;
-  };
-  player.tech_.hls.playlists.state = 'SWITCHING_MEDIA';
+  // force a playlist switch
+  player.tech_.hls.playlists.media('media3.m3u8');
 
   standardXHRResponse(requests.shift()); // segment 0
+  player.tech_.hls.sourceBuffer.trigger('updateend');
 
-  equal(requests.length, 0, 'no requests outstanding');
+  equal(requests.length, 1, 'only the playlist request outstanding');
   player.tech_.hls.checkBuffer_();
-  equal(requests.length, 0, 'delays segment fetching');
+  equal(requests.length, 1, 'delays segment fetching');
 
-  player.tech_.hls.playlists.state = 'LOADED_METADATA';
+  standardXHRResponse(requests.shift()); // media3
   player.tech_.hls.checkBuffer_();
   equal(requests.length, 1, 'resumes segment fetching');
 });
@@ -1841,52 +1743,24 @@ QUnit.skip('translates ID3 PTS values across discontinuities', function() {
   equal(track.cues[1].endTime, 11, 'second cue ended at the correct time');
 });
 
-test('adjusts the segment offsets for out-of-buffer seeking', function() {
-  player.src({
-    src: 'manifest/media.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-  openMediaSource(player);
-  standardXHRResponse(requests.shift()); // media
-  player.tech_.hls.sourceBuffer.buffered = function() {
-    return videojs.createTimeRange(0, 20);
-  };
-  equal(player.tech_.hls.mediaIndex, 0, 'starts at zero');
-
-  player.tech_.setCurrentTime(35);
-  clock.tick(1);
-  // drop the aborted segment
-  requests.shift();
-  equal(player.tech_.hls.mediaIndex, 3, 'moved the mediaIndex');
-  standardXHRResponse(requests.shift());
-});
-
 test('seeks between buffered time ranges', function() {
   player.src({
-    src: 'manifest/media.m3u8',
+    src: 'media.m3u8',
     type: 'application/vnd.apple.mpegurl'
   });
   openMediaSource(player);
   standardXHRResponse(requests.shift()); // media
   player.tech_.buffered = function() {
-    return {
-      length: 2,
-      ranges_: [[0, 10], [20, 30]],
-      start: function(i) {
-        return this.ranges_[i][0];
-      },
-      end: function(i) {
-        return this.ranges_[i][1];
-      }
-    };
+    return videojs.createTimeRange([[0, 10], [20, 30]]);
   };
 
   player.tech_.setCurrentTime(15);
   clock.tick(1);
   // drop the aborted segment
   requests.shift();
-  equal(player.tech_.hls.mediaIndex, 1, 'updated the mediaIndex');
-  standardXHRResponse(requests.shift());
+  equal(requests[0].url,
+        absoluteUrl('media-00002.ts'),
+        'requested the correct segment');
 });
 
 test('does not modify the media index for in-buffer seeking', function() {
@@ -1979,40 +1853,6 @@ test('duration is Infinity for live playlists', function() {
               'duration is infinity');
 });
 
-test('updates the media index when a playlist reloads', function() {
-  player.src({
-    src: 'http://example.com/live-updating.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-  openMediaSource(player);
-  player.tech_.trigger('play');
-
-  requests[0].respond(200, null,
-                      '#EXTM3U\n' +
-                      '#EXTINF:10,\n' +
-                      '0.ts\n' +
-                      '#EXTINF:10,\n' +
-                      '1.ts\n' +
-                      '#EXTINF:10,\n' +
-                      '2.ts\n');
-  standardXHRResponse(requests[1]);
-  // play the stream until 2.ts is playing
-  player.tech_.hls.mediaIndex = 3;
-  // trigger a playlist refresh
-  player.tech_.hls.playlists.trigger('mediaupdatetimeout');
-  requests[2].respond(200, null,
-                      '#EXTM3U\n' +
-                      '#EXT-X-MEDIA-SEQUENCE:1\n' +
-                      '#EXTINF:10,\n' +
-                      '1.ts\n' +
-                      '#EXTINF:10,\n' +
-                      '2.ts\n' +
-                      '#EXTINF:10,\n' +
-                      '3.ts\n');
-
-  strictEqual(player.tech_.hls.mediaIndex, 2, 'mediaIndex is updated after the reload');
-});
-
 test('live playlist starts three target durations before live', function() {
   var mediaPlaylist;
   player.src({
@@ -2040,30 +1880,11 @@ test('live playlist starts three target durations before live', function() {
   player.tech_.trigger('play');
   clock.tick(1);
   mediaPlaylist = player.tech_.hls.playlists.media();
-  equal(player.tech_.hls.mediaIndex, 1, 'mediaIndex is updated at play');
   equal(player.currentTime(), player.tech_.hls.seekable().end(0), 'seeked to the seekable end');
 
   equal(requests.length, 1, 'begins buffering');
 });
 
-test('does not reset live currentTime if mediaIndex is one beyond the last available segment', function() {
-  var playlist = {
-    mediaSequence: 20,
-    targetDuration: 9,
-    segments: [{
-      duration: 3
-    }, {
-      duration: 3
-    }, {
-      duration: 3
-    }]
-  };
-
-  equal(playlist.segments.length,
-        videojs.Hls.translateMediaIndex(playlist.segments.length, playlist, playlist),
-        'did not change mediaIndex');
-});
-
 test('live playlist starts with correct currentTime value', function() {
   player.src({
     src: 'http://example.com/manifest/liveStart30sBefore.m3u8',
@@ -2117,39 +1938,6 @@ test('resets the time to a seekable position when resuming a live stream ' +
   player.tech_.trigger('seeked');
 });
 
-test('mediaIndex is zero before the first segment loads', function() {
-  window.manifests['first-seg-load'] =
-    '#EXTM3U\n' +
-    '#EXTINF:10,\n' +
-    '0.ts\n';
-  player.src({
-    src: 'http://example.com/first-seg-load.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-  openMediaSource(player);
-
-  strictEqual(player.tech_.hls.mediaIndex, 0, 'mediaIndex is zero');
-});
-
-test('mediaIndex returns correctly at playlist boundaries', function() {
-  player.src({
-    src: 'http://example.com/master.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-
-  openMediaSource(player);
-  standardXHRResponse(requests.shift()); // master
-  standardXHRResponse(requests.shift()); // media
-
-  strictEqual(player.tech_.hls.mediaIndex, 0, 'mediaIndex is zero at first segment');
-
-  // seek to end
-  player.tech_.setCurrentTime(40);
-  clock.tick(1);
-
-  strictEqual(player.tech_.hls.mediaIndex, 3, 'mediaIndex is 3 at last segment');
-});
-
 test('reloads out-of-date live playlists when switching variants', function() {
   player.src({
     src: 'http://example.com/master.m3u8',
@@ -3209,4 +2997,42 @@ test('does not download segments if preload option set to none', function() {
   equal(requests.length, 0, 'did not download any segments');
 });
 
+module('Buffer Inspection');
+
+test('detects time range edges added by updates', function() {
+  var edges;
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([[0, 10]]),
+                                         videojs.createTimeRange([[0, 11]]));
+  deepEqual(edges, [{ end: 11 }], 'detected a forward addition');
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([[5, 10]]),
+                                         videojs.createTimeRange([[0, 10]]));
+  deepEqual(edges, [{ start: 0 }], 'detected a backward addition');
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([[5, 10]]),
+                                         videojs.createTimeRange([[0, 11]]));
+  deepEqual(edges, [
+    { start: 0 }, { end: 11 }
+  ], 'detected forward and backward additions');
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([[0, 10]]),
+                                         videojs.createTimeRange([[0, 10]]));
+  deepEqual(edges, [], 'detected no addition');
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([]),
+                                         videojs.createTimeRange([[0, 10]]));
+  deepEqual(edges, [
+    { start: 0 },
+    { end: 10 }
+  ], 'detected an initial addition');
+
+  edges = videojs.Hls.bufferedAdditions_(videojs.createTimeRange([[0, 10]]),
+                                         videojs.createTimeRange([[0, 10], [20, 30]]));
+  deepEqual(edges, [
+    { start: 20 },
+    { end: 30}
+  ], 'detected a non-contiguous addition');
+});
+
 })(window, window.videojs);