Add support for EXT-X-DATERANGE tag at media playlist level (#168)

Author: bbert

parse.ts

@@ -501,6 +501,27 @@ function parseMasterPlaylist(lines: Line[], params: Record<string, any>): Master
   return playlist;
 }
 
+function parseDateRange(attributes) {
+  const attrs: Record<string, any> = {};
+  for (const key of Object.keys(attributes)) {
+    if (key.startsWith('SCTE35-') || key.startsWith('X-')) {
+      attrs[key] = attributes[key];
+    }
+  }
+  const dateRange = new DateRange({
+    id: attributes['ID'],
+    classId: attributes['CLASS'],
+    start: attributes['START-DATE'],
+    cue: attributes['CUE'],
+    end: attributes['END-DATE'],
+    duration: attributes['DURATION'],
+    plannedDuration: attributes['PLANNED-DURATION'],
+    endOnNext: attributes['END-ON-NEXT'],
+    attributes: attrs
+  });
+  return dateRange;
+}
+
 function parseSegment(lines: Line[], uri: string, start: number, end: number, mediaSequenceNumber: number, discontinuitySequence: number, params: Record<string, any>): Segment {
   const segment = new Segment({uri, mediaSequenceNumber, discontinuitySequence});
   let mapHint = false;
@@ -558,23 +579,7 @@ function parseSegment(lines: Line[], uri: string, start: number, end: number, me
     } else if (name === 'EXT-X-PROGRAM-DATE-TIME') {
       segment.programDateTime = value;
     } else if (name === 'EXT-X-DATERANGE') {
-      const attrs: Record<string, any> = {};
-      for (const key of Object.keys(attributes)) {
-        if (key.startsWith('SCTE35-') || key.startsWith('X-')) {
-          attrs[key] = attributes[key];
-        }
-      }
-      segment.dateRange = new DateRange({
-        id: attributes['ID'],
-        classId: attributes['CLASS'],
-        start: attributes['START-DATE'],
-        cue: attributes['CUE'],
-        end: attributes['END-DATE'],
-        duration: attributes['DURATION'],
-        plannedDuration: attributes['PLANNED-DURATION'],
-        endOnNext: attributes['END-ON-NEXT'],
-        attributes: attrs
-      });
+      segment.dateRange = parseDateRange(attributes);
     } else if (name === 'EXT-X-CUE-OUT') {
       segment.markers.push(new SpliceInfo({
         type: 'OUT',
@@ -783,6 +788,9 @@ function parseMediaPlaylist(lines: Line[], params: Record<string, any>): MediaPl
     } else if (name === 'EXT-X-DEFINE') {
       playlist.defines ||= [];
       playlist.defines.push(attributes);
+    } else if (name === 'EXT-X-DATERANGE') {
+      const dateRange = parseDateRange(attributes);
+      playlist.dateRanges.push(dateRange);
     } else if (typeof line === 'string') {
       // uri
       if (segmentStart === -1) {

stringify.ts

@@ -301,6 +301,9 @@ function buildMediaPlaylist(lines: LineArray, playlist: MediaPlaylist, postProce
   if (playlist.skip > 0) {
     lines.push(`#EXT-X-SKIP:SKIPPED-SEGMENTS=${playlist.skip}`);
   }
+  for (const dateRange of playlist.dateRanges) {
+    lines.push(buildDateRange(dateRange));
+  }
   for (const [i, segment] of playlist.segments.entries()) {
     const base = lines.length;
     let markerType = '';

types.ts

@@ -340,6 +340,7 @@ class MediaPlaylist extends Playlist {
   endlist: boolean;
   playlistType?: 'EVENT' | 'VOD';
   isIFrame?: boolean;
+  dateRanges: DateRange[];
   segments: Segment[];
   prefetchSegments: PrefetchSegment[];
   lowLatencyCompatibility?: LowLatencyCompatibility;
@@ -357,6 +358,7 @@ class MediaPlaylist extends Playlist {
       endlist = false,
       playlistType,
       isIFrame,
+      dateRanges = [],
       segments = [],
       prefetchSegments = [],
       lowLatencyCompatibility,
@@ -371,6 +373,7 @@ class MediaPlaylist extends Playlist {
     this.endlist = endlist;
     this.playlistType = playlistType;
     this.isIFrame = isIFrame;
+    this.dateRanges = dateRanges;
     this.segments = segments;
     this.prefetchSegments = prefetchSegments;
     this.lowLatencyCompatibility = lowLatencyCompatibility;
@@ -394,7 +397,7 @@ class Segment extends Data {
   key?: Key;
   map: MediaInitializationSection;
   programDateTime?: Date;
-  dateRange: DateRange;
+  dateRange?: DateRange;
   markers: SpliceInfo[];
   parts: PartialSegment[];
   gap?: boolean;