Merge pull request #515 from 'tenacex-feature/byterange-support-dev' into development

Add support for EXT-X-BYTERANGE

@@ -894,7 +894,8 @@ videojs.HlsHandler.prototype.fillBuffer = function(mediaIndex) {
   // we have entered a state where we are fetching the same segment,
   // try to walk forward
   if (this.lastSegmentLoaded_ &&
-      this.lastSegmentLoaded_ === this.playlistUriToUrl(segment.uri)) {
+      this.playlistUriToUrl(this.lastSegmentLoaded_.uri) === this.playlistUriToUrl(segment.uri) &&
+      this.lastSegmentLoaded_.byterange === segment.byterange) {
     return this.fillBuffer(mediaIndex + 1);
   }
 
@@ -961,6 +962,29 @@ videojs.HlsHandler.prototype.playlistUriToUrl = function(segmentRelativeUrl) {
   return playListUrl;
 };
 
+/*  Turns segment byterange into a string suitable for use in
+ *  HTTP Range requests
+ */
+videojs.HlsHandler.prototype.byterangeStr_ = function(byterange) {
+    var byterangeStart, byterangeEnd;
+
+    // `byterangeEnd` is one less than `offset + length` because the HTTP range
+    // header uses inclusive ranges
+    byterangeEnd = byterange.offset + byterange.length - 1;
+    byterangeStart = byterange.offset;
+    return "bytes=" + byterangeStart + "-" + byterangeEnd;
+};
+
+/*  Defines headers for use in the xhr request for a particular segment.
+ */
+videojs.HlsHandler.prototype.segmentXhrHeaders_ = function(segment) {
+  var headers = {};
+  if ('byterange' in segment) {
+      headers['Range'] = this.byterangeStr_(segment.byterange);
+  }
+  return headers;
+};
+
 /*
  * Sets `bandwidth`, `segmentXhrTime`, and appends to the `bytesReceived.
  * Expects an object with:
@@ -1054,7 +1078,8 @@ videojs.HlsHandler.prototype.loadSegment = function(segmentInfo) {
     // Set xhr timeout to 150% of the segment duration to allow us
     // some time to switch renditions in the event of a catastrophic
     // decrease in network performance or a server issue.
-    timeout: (segment.duration * 1.5) * 1000
+    timeout: (segment.duration * 1.5) * 1000,
+    headers: this.segmentXhrHeaders_(segment)
   }, function(error, request) {
     // This is a timeout of a previously aborted segment request
     // so simply ignore it
@@ -1085,7 +1110,7 @@ videojs.HlsHandler.prototype.loadSegment = function(segmentInfo) {
       return;
     }
 
-    self.lastSegmentLoaded_ = segmentInfo.uri;
+    self.lastSegmentLoaded_ = segment;
     self.setBandwidth(request);
 
     if (segment.key) {

@@ -28,9 +28,13 @@
         request.timedout = false;
       }
 
-      // videojs.xhr no longer consider status codes outside of 200 and 0 (for file uris) to be
-      // errors but the old XHR did so emulate that behavior
-      if (!error && response.statusCode !== 200 && response.statusCode !== 0) {
+      // videojs.xhr no longer considers status codes outside of 200 and 0
+      // (for file uris) to be errors, but the old XHR did, so emulate that
+      // behavior. Status 206 may be used in response to byterange requests.
+      if (!error &&
+           response.statusCode !== 200 &&
+           response.statusCode !== 206 &&
+           response.statusCode !== 0) {
         error = new Error('XHR Failed with a response of: ' +
           (request && (request.response || request.responseText)));
       }

@@ -324,6 +324,56 @@ test('starts playing if autoplay is specified', function() {
   strictEqual(1, plays, 'play was called');
 });
 
+test('XHR requests first byte range on play', function() {
+  player.src({
+    src: 'manifest/playlist.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+  player.tech_.triggerReady();
+  clock.tick(1);
+  player.tech_.trigger('play');
+  openMediaSource(player);
+  standardXHRResponse(requests[0]);
+  equal(requests[1].headers.Range, "bytes=0-522827");
+});
+
+test('Seeking requests correct byte range', function() {
+  player.src({
+    src: 'manifest/playlist.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+  player.tech_.triggerReady();
+  clock.tick(1);
+  player.tech_.trigger('play');
+  openMediaSource(player);
+  standardXHRResponse(requests[0]);
+  player.tech_.hls.sourceBuffer.trigger('updateend');
+  clock.tick(1);
+  player.currentTime(40);
+  clock.tick(1);
+  equal(requests[2].headers.Range, "bytes=2299992-2835603");
+});
+
+test('if buffered, will request second segment byte range', function() {
+  player.src({
+    src: 'manifest/playlist.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+  player.tech_.triggerReady();
+  clock.tick(1);
+  player.tech_.trigger('play');
+  openMediaSource(player);
+  player.tech_.buffered = function() {
+    return videojs.createTimeRange(0, 20);
+  };
+  standardXHRResponse(requests[0]);
+  standardXHRResponse(requests[1]);
+  player.tech_.hls.sourceBuffer.trigger('updateend');
+  player.tech_.hls.checkBuffer_();
+  clock.tick(100);
+  equal(requests[2].headers.Range, "bytes=1823412-2299991");
+});
+
 test('autoplay seeks to the live point after playlist load', function() {
   var currentTime = 0;
   player.autoplay(true);