feat(HLS) Add support to blocking playlist reload by adding the CAN-B…

…LOCK-RELOAD=YES
shaka-project · Jun 12, 2023 · f9dd6e3 · f9dd6e3
1 parent 70823f9
commit f9dd6e3
Showing 1 changed file with 22 additions and 10 deletions.
diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -349,16 +349,18 @@ shaka.hls.HlsParser = class {
         // 'EXT-X-SKIP' tag in the media playlist.
         queryData.add('_HLS_skip', 'YES');
       }
-      if (streamInfo.nextMediaSequence >= 0) {
-        // Indicates that the server must hold the request until a Playlist
-        // contains a Media Segment with Media Sequence
-        queryData.add('_HLS_msn', String(streamInfo.nextMediaSequence));
-      }
-      if (streamInfo.nextPart >= 0) {
-        // Indicates, in combination with _HLS_msn, that the server must hold
-        // the request until a Playlist contains Partial Segment N of Media
-        // Sequence Number M or later.
-        queryData.add('_HLS_part', String(streamInfo.nextPart));
+      if (streamInfo.canBlockReload) {
+        if (streamInfo.nextMediaSequence >= 0) {
+          // Indicates that the server must hold the request until a Playlist
+          // contains a Media Segment with Media Sequence
+          queryData.add('_HLS_msn', String(streamInfo.nextMediaSequence));
+        }
+        if (streamInfo.nextPart >= 0) {
+          // Indicates, in combination with _HLS_msn, that the server must hold
+          // the request until a Playlist contains Partial Segment N of Media
+          // Sequence Number M or later.
+          queryData.add('_HLS_part', String(streamInfo.nextPart));
+        }
       }
       if (queryData.getCount()) {
         uriObj.setQueryData(queryData);
@@ -1960,6 +1962,7 @@ shaka.hls.HlsParser = class {
       maxTimestamp: 0,
       mediaSequenceToStartTime: new Map(),
       canSkipSegments: false,
+      canBlockReload: false,
       hasEndList: false,
       firstSequenceNumber: -1,
       nextMediaSequence: -1,
@@ -2007,6 +2010,7 @@ shaka.hls.HlsParser = class {
       streamInfo.minTimestamp = realStreamInfo.minTimestamp;
       streamInfo.maxTimestamp = realStreamInfo.maxTimestamp;
       streamInfo.canSkipSegments = realStreamInfo.canSkipSegments;
+      streamInfo.canBlockReload = realStreamInfo.canBlockReload;
       streamInfo.hasEndList = realStreamInfo.hasEndList;
       streamInfo.mediaSequenceToStartTime =
           realStreamInfo.mediaSequenceToStartTime;
@@ -2297,6 +2301,8 @@ shaka.hls.HlsParser = class {
         playlist.tags, 'EXT-X-SERVER-CONTROL');
     const canSkipSegments = serverControlTag ?
           serverControlTag.getAttribute('CAN-SKIP-UNTIL') != null : false;
+    const canBlockReload = serverControlTag ?
+          serverControlTag.getAttribute('CAN-BLOCK-RELOAD') == 'YES' : false;
 
     const mediaSequenceNumber = shaka.hls.Utils.getFirstTagWithNameAsNumber(
         playlist.tags, 'EXT-X-MEDIA-SEQUENCE', 0);
@@ -2320,6 +2326,7 @@ shaka.hls.HlsParser = class {
       minTimestamp: firstStartTime,
       maxTimestamp: lastEndTime,
       canSkipSegments,
+      canBlockReload,
       hasEndList: false,
       firstSequenceNumber: -1,
       nextMediaSequence,
@@ -3687,6 +3694,7 @@ shaka.hls.HlsParser = class {
  *   maxTimestamp: number,
  *   mediaSequenceToStartTime: !Map.<number, number>,
  *   canSkipSegments: boolean,
+ *   canBlockReload: boolean,
  *   hasEndList: boolean,
  *   firstSequenceNumber: number,
  *   nextMediaSequence: number,
@@ -3719,6 +3727,10 @@ shaka.hls.HlsParser = class {
  * @property {boolean} canSkipSegments
  *   True if the server supports delta playlist updates, and we can send a
  *   request for a playlist that can skip older media segments.
+ * @property {boolean} canBlockReload
+ *   True if the server supports blocking playlist reload, and we can send a
+ *   request for a playlist that can block reload until some segments are
+ *   present.
  * @property {boolean} hasEndList
  *   True if the stream has an EXT-X-ENDLIST tag.
  * @property {number} firstSequenceNumber