Add support for multiple EXT-X-MAP tags

src/controller/audio-stream-controller.js

@@ -194,11 +194,7 @@ class AudioStreamController extends BaseStreamController {
             }
           }
         }
-        if (trackDetails.initSegment && !trackDetails.initSegment.data) {
-          frag = trackDetails.initSegment;
-        } // eslint-disable-line brace-style
-        // if bufferEnd before start of playlist, load first fragment
-        else if (bufferEnd <= start) {
+        if (bufferEnd <= start) {
           frag = fragments[0];
           if (this.videoTrackCC !== null && frag.cc !== this.videoTrackCC) {
             // Ensure we find a fragment which matches the continuity of the video track
@@ -281,6 +277,9 @@ class AudioStreamController extends BaseStreamController {
             logger.log(`Loading ${frag.sn}, cc: ${frag.cc} of [${trackDetails.startSN} ,${trackDetails.endSN}],track ${trackId}, currentTime:${pos},bufferEnd:${bufferEnd.toFixed(3)}`);
             // only load if fragment is not loaded or if in audio switch
             // we force a frag loading in audio switch as fragment tracker might not have evicted previous frags in case of quick audio switch
+            if (trackDetails.initSegments[frag.initSegment] && !trackDetails.initSegments[frag.initSegment].data) {
+              frag = trackDetails.initSegments[frag.initSegment].fragment;
+            }
             this.fragCurrent = frag;
             if (audioSwitch || this.fragmentTracker.getState(frag) === FragmentState.NOT_LOADED) {
               if (frag.sn !== 'initSegment') {
@@ -504,7 +503,7 @@ class AudioStreamController extends BaseStreamController {
         this.state = State.IDLE;
 
         stats.tparsed = stats.tbuffered = performance.now();
-        details.initSegment.data = data.payload;
+        details.initSegments[data.frag.relurl].data = data.payload;
         this.hls.trigger(Event.FRAG_BUFFERED, { stats: stats, frag: fragCurrent, id: 'audio' });
         this.tick();
       } else {
@@ -518,8 +517,8 @@ class AudioStreamController extends BaseStreamController {
         // Check if we have video initPTS
         // If not we need to wait for it
         let initPTS = this.initPTS[cc];
-        let initSegmentData = details.initSegment ? details.initSegment.data : [];
-        if (details.initSegment || initPTS !== undefined) {
+        const initSegmentData = details.initSegments[fragCurrent.initSegment] ? details.initSegments[fragCurrent.initSegment].data : [];
+        if (details.initSegments[fragCurrent.initSegment] || initPTS !== undefined) {
           this.pendingBuffering = true;
           logger.log(`Demuxing ${sn} of [${details.startSN} ,${details.endSN}],track ${trackId}`);
           // time Offset is accurate if level PTS is known, or if playlist is not sliding (not live)

src/controller/level-helper.js

@@ -110,9 +110,12 @@ export function updateFragPTSDTS (details, frag, startPTS, endPTS, startDTS, end
 }
 
 export function mergeDetails (oldDetails, newDetails) {
-  // potentially retrieve cached initsegment
-  if (newDetails.initSegment && oldDetails.initSegment) {
-    newDetails.initSegment = oldDetails.initSegment;
+  // potentially retrieve cached initsegments
+  if (newDetails.initSegments && oldDetails.initSegments) {
+    newDetails.initSegments = {
+      ...newDetails.initSegments,
+      ...oldDetails.initSegments
+    };
   }
 
   // check if old/new playlists have fragments in common

src/controller/stream-controller.js

@@ -230,34 +230,33 @@ class StreamController extends BaseStreamController {
       bufferEnd = bufferInfo.end,
       frag;
 
-    if (levelDetails.initSegment && !levelDetails.initSegment.data) {
-      frag = levelDetails.initSegment;
-    } else {
-      // in case of live playlist we need to ensure that requested position is not located before playlist start
-      if (levelDetails.live) {
-        let initialLiveManifestSize = this.config.initialLiveManifestSize;
-        if (fragLen < initialLiveManifestSize) {
-          logger.warn(`Can not start playback of a level, reason: not enough fragments ${fragLen} < ${initialLiveManifestSize}`);
-          return;
-        }
+    // in case of live playlist we need to ensure that requested position is not located before playlist start
+    if (levelDetails.live) {
+      let initialLiveManifestSize = this.config.initialLiveManifestSize;
+      if (fragLen < initialLiveManifestSize) {
+        logger.warn(`Can not start playback of a level, reason: not enough fragments ${fragLen} < ${initialLiveManifestSize}`);
+        return;
+      }
 
-        frag = this._ensureFragmentAtLivePoint(levelDetails, bufferEnd, start, end, fragPrevious, fragments, fragLen);
-        // if it explicitely returns null don't load any fragment and exit function now
-        if (frag === null) {
-          return;
-        }
-      } else {
-        // VoD playlist: if bufferEnd before start of playlist, load first fragment
-        if (bufferEnd < start) {
-          frag = fragments[0];
-        }
+      frag = this._ensureFragmentAtLivePoint(levelDetails, bufferEnd, start, end, fragPrevious, fragments, fragLen);
+      // if it explicitely returns null don't load any fragment and exit function now
+      if (frag === null) {
+        return;
+      }
+    } else {
+      // VoD playlist: if bufferEnd before start of playlist, load first fragment
+      if (bufferEnd < start) {
+        frag = fragments[0];
       }
     }
     if (!frag) {
       frag = this._findFragment(start, fragPrevious, fragLen, fragments, bufferEnd, end, levelDetails);
     }
 
     if (frag) {
+      if (levelDetails.initSegments[frag.initSegment] && !levelDetails.initSegments[frag.initSegment].data) {
+        frag = levelDetails.initSegments[frag.initSegment].fragment;
+      }
       if (frag.encrypted) {
         logger.log(`Loading key for ${frag.sn} of [${levelDetails.startSN} ,${levelDetails.endSN}],level ${level}`);
         this._loadKey(frag);
@@ -848,7 +847,7 @@ class StreamController extends BaseStreamController {
       } else if (fragLoaded.sn === 'initSegment') {
         this.state = State.IDLE;
         stats.tparsed = stats.tbuffered = window.performance.now();
-        details.initSegment.data = data.payload;
+        details.initSegments[data.frag.relurl].data = data.payload;
         hls.trigger(Event.FRAG_BUFFERED, { stats: stats, frag: fragCurrent, id: 'main' });
         this.tick();
       } else {
@@ -868,7 +867,7 @@ class StreamController extends BaseStreamController {
 
         // time Offset is accurate if level PTS is known, or if playlist is not sliding (not live) and if media is not seeking (this is to overcome potential timestamp drifts between playlists and fragments)
         const accurateTimeOffset = !(media && media.seeking) && (details.PTSKnown || !details.live);
-        const initSegmentData = details.initSegment ? details.initSegment.data : [];
+        const initSegmentData = details.initSegments[fragCurrent.initSegment] ? details.initSegments[fragCurrent.initSegment].data : [];
         const audioCodec = this._getAudioCodec(currentLevel);
 
         // transmux the MPEG-TS data to ISO-BMFF segments

src/loader/fragment.ts

@@ -42,6 +42,10 @@ export default class Fragment {
   // _decryptdata will set the IV for this segment based on the segment number in the fragment
   public levelkey?: LevelKey;
 
+  // initSegment is the relurl of the initsegment associated with the fragment which can be found
+  // on level details
+  public initSegment?: string;
+
   // setByteRange converts a EXT-X-BYTERANGE attribute into a two element array
   setByteRange (value: string, previousFrag?: Fragment) {
     const params = value.split('@', 2);

src/loader/init-segment.ts

@@ -0,0 +1,10 @@
+import Fragment from './fragment';
+
+export default class InitSegment {
+  public fragment: Fragment;
+  public data: ArrayBuffer | null = null;
+
+  constructor (fragment: Fragment) {
+    this.fragment = fragment;
+  }
+}

src/loader/level.js

@@ -4,7 +4,7 @@ export default class Level {
     this.endCC = 0;
     this.endSN = 0;
     this.fragments = [];
-    this.initSegment = null;
+    this.initSegments = {};
     this.live = true;
     this.needSidxRanges = false;
     this.startCC = 0;

src/loader/m3u8-parser.js

@@ -1,6 +1,7 @@
 import * as URLToolkit from 'url-toolkit';
 
 import Fragment from './fragment';
+import InitSegment from './init-segment';
 import Level from './level';
 import LevelKey from './level-key';
 
@@ -156,6 +157,7 @@ export default class M3U8Parser {
     let frag = new Fragment();
     let result;
     let i;
+    let initSegment = null;
 
     let firstPdtIndex = null;
 
@@ -180,6 +182,9 @@ export default class M3U8Parser {
           frag.cc = cc;
           frag.urlId = levelUrlId;
           frag.baseurl = baseurl;
+          if (initSegment) {
+            frag.initSegment = initSegment.fragment.relurl;
+          }
           // avoid sliced strings    https://github.com/video-dev/hls.js/issues/939
           frag.relurl = (' ' + result[3]).slice(1);
           assignProgramDateTime(frag, prevFrag);
@@ -286,6 +291,9 @@ export default class M3U8Parser {
           frag.type = type;
           frag.sn = 'initSegment';
           level.initSegment = frag;
+          frag.cc = cc;
+          initSegment = new InitSegment(frag);
+          level.initSegments[frag.relurl] = initSegment;
           frag = new Fragment();
           frag.rawProgramDateTime = level.initSegment.rawProgramDateTime;
           break;