Do not require EXT-X-MEDIA-SEQUENCE in HLS live

Closes shaka-project#1189 Change-Id: Iae6f4f4524bb9895f8b211491793cf7626661a5d
daniel-vanveen · Dec 13, 2017 · 2e5b856 · 2e5b856
1 parent 2075050
commit 2e5b856
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Showing 3 changed files with 18 additions and 20 deletions.
diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -232,13 +232,6 @@ shaka.hls.HlsParser.prototype.updateStream_ = function(streamInfo, uri) {
 
     var mediaSequenceTag = Utils.getFirstTagWithName(playlist.tags,
                                                      'EXT-X-MEDIA-SEQUENCE');
-    if (this.presentationType_ == PresentationType.LIVE && !mediaSequenceTag) {
-      // This only applies to LIVE, not EVENT.
-      throw new shaka.util.Error(
-          shaka.util.Error.Severity.CRITICAL,
-          shaka.util.Error.Category.MANIFEST,
-          shaka.util.Error.Code.HLS_MEDIA_SEQUENCE_REQUIRED_IN_LIVE_STREAMS);
-    }
 
     var startPosition = mediaSequenceTag ? Number(mediaSequenceTag.value) : 0;
     var stream = streamInfo.stream;
@@ -845,7 +838,6 @@ shaka.hls.HlsParser.prototype.createStreamInfo_ = function(uri, allCodecs,
   var Utils = shaka.hls.Utils;
   var ContentType = shaka.util.ManifestParserUtils.ContentType;
   var HlsParser = shaka.hls.HlsParser;
-  var PresentationType = shaka.hls.HlsParser.PresentationType_;
 
   var relativeUri = uri;
   uri = Utils.constructAbsoluteUri(this.manifestUri_, uri);
@@ -879,13 +871,6 @@ shaka.hls.HlsParser.prototype.createStreamInfo_ = function(uri, allCodecs,
 
     var mediaSequenceTag = Utils.getFirstTagWithName(playlist.tags,
                                                      'EXT-X-MEDIA-SEQUENCE');
-    if (this.presentationType_ == PresentationType.LIVE && !mediaSequenceTag) {
-      // This only applies to LIVE, not EVENT.
-      throw new shaka.util.Error(
-          shaka.util.Error.Severity.CRITICAL,
-          shaka.util.Error.Category.MANIFEST,
-          shaka.util.Error.Code.HLS_MEDIA_SEQUENCE_REQUIRED_IN_LIVE_STREAMS);
-    }
 
     var startPosition = mediaSequenceTag ? Number(mediaSequenceTag.value) : 0;
 

diff --git a/lib/util/error.js b/lib/util/error.js
@@ -531,11 +531,7 @@ shaka.util.Error.Code = {
    */
   'HLS_COULD_NOT_PARSE_SEGMENT_START_TIME': 4030,
 
-  /**
-   * HLS parser was unable to find the EXT-X-MEDIA-SEQUENCE tag, which this
-   * implementation requires for live HLS streams.
-   */
-  'HLS_MEDIA_SEQUENCE_REQUIRED_IN_LIVE_STREAMS': 4031,
+  // RETIRED: 'HLS_MEDIA_SEQUENCE_REQUIRED_IN_LIVE_STREAMS': 4031,
 
 
   // RETIRED: 'INCONSISTENT_BUFFER_STATE': 5000,

diff --git a/test/hls/hls_live_unit.js b/test/hls/hls_live_unit.js
@@ -338,6 +338,13 @@ describe('HlsParser live', function() {
       'test:/main.mp4\n'
     ].join('');
 
+    var mediaWithoutSequenceNumber = [
+      '#EXTM3U\n',
+      '#EXT-X-TARGETDURATION:5\n',
+      '#EXTINF:2,\n',
+      'test:/main.mp4\n'
+    ].join('');
+
     var mediaWithByteRange = [
       '#EXTM3U\n',
       '#EXT-X-TARGETDURATION:5\n',
@@ -380,6 +387,16 @@ describe('HlsParser live', function() {
       }).catch(fail).then(done);
     });
 
+    it('does not fail on a missing sequence number', function(done) {
+      fakeNetEngine.setResponseMap({
+        'test:/master': toUTF8(master),
+        'test:/video': toUTF8(mediaWithoutSequenceNumber),
+        'test:/main.mp4': segmentData
+      });
+
+      parser.start('test:/master', playerInterface).catch(fail).then(done);
+    });
+
     describe('update', function() {
       beforeAll(function() {
         jasmine.clock().install();