fix: Handle audio only playlists without main playlists

scripts/sources.json

@@ -357,5 +357,17 @@
     "uri": "https://d2zihajmogu5jn.cloudfront.net/pdt-test-source/endlist.m3u8",
     "mimetype": "application/x-mpegurl",
     "features": []
+  },
+  {
+    "name": "audio only dash, two groups",
+    "uri": "https://d2zihajmogu5jn.cloudfront.net/audio-only-dash/dash.mpd",
+    "mimetype": "application/dash+xml",
+    "features": []
+  },
+  {
+    "name": "video only dash, two renditions",
+    "uri": "https://d2zihajmogu5jn.cloudfront.net/video-only-dash/dash.mpd",
+    "mimetype": "application/dash+xml",
+    "features": []
   }
 ]

src/master-playlist-controller.js

@@ -330,6 +330,53 @@ export class MasterPlaylistController extends videojs.EventTarget {
     this.abrTimer_ = null;
   }
 
+  getAudioTrackPlaylists_() {
+    const playlists = [];
+    const master = this.master();
+
+    if (!master && !master.mediaGroups && !master.mediaGroups.AUDIO) {
+      return playlists;
+    }
+
+    const AUDIO = master.mediaGroups.AUDIO;
+    const groupKeys = Object.keys(AUDIO);
+    let track;
+
+    // get the current active track
+    if (Object.keys(this.mediaTypes_.AUDIO.groups).length) {
+      track = this.mediaTypes_.AUDIO.activeTrack();
+    // or get the default track from master if mediaTypes_ isn't setup yet
+    } else {
+      // default group is `main` or just the first group.
+      const defaultGroup = AUDIO.main || groupKeys.length && AUDIO[groupKeys[0]];
+
+      for (const label in defaultGroup) {
+        if (defaultGroup[label].default) {
+          track = {label};
+          break;
+        }
+      }
+    }
+
+    if (!track) {
+      return playlists;
+    }
+
+    for (const group in AUDIO) {
+      if (AUDIO[group][track.label]) {
+        const properties = AUDIO[group][track.label];
+
+        if (properties.playlists) {
+          playlists.push.apply(playlists, properties.playlists);
+        } else {
+          playlists.push(properties);
+        }
+      }
+    }
+
+    return playlists;
+  }
+
   /**
    * Register event handlers on the master playlist loader. A helper
    * function for construction time.

src/media-groups.js

@@ -2,6 +2,8 @@ import videojs from 'video.js';
 import PlaylistLoader from './playlist-loader';
 import DashPlaylistLoader from './dash-playlist-loader';
 import noop from './util/noop';
+import {isAudioOnly} from './playlist.js';
+import logger from './util/logger';
 
 /**
  * Convert the properties of an HLS track into an audioTrackKind.
@@ -77,13 +79,12 @@ export const onGroupChanged = (type, settings) => () => {
     },
     mediaTypes: { [type]: mediaType }
   } = settings;
-  const activeTrack = mediaType.activeTrack();
-  const activeGroup = mediaType.activeGroup(activeTrack);
+  const activeGroup = mediaType.getActiveGroup();
   const previousActiveLoader = mediaType.activePlaylistLoader;
 
   stopLoaders(segmentLoader, mediaType);
 
-  if (!activeGroup) {
+  if (!activeGroup || activeGroup.masterPlaylist) {
     // there is no group active
     return;
   }
@@ -132,15 +133,21 @@ export const onGroupChanging = (type, settings) => () => {
  */
 export const onTrackChanged = (type, settings) => () => {
   const {
+    masterPlaylistLoader,
     segmentLoaders: {
       [type]: segmentLoader,
       main: mainSegmentLoader
     },
     mediaTypes: { [type]: mediaType }
   } = settings;
   const activeTrack = mediaType.activeTrack();
-  const activeGroup = mediaType.activeGroup(activeTrack);
+  const activeGroup = mediaType.getActiveGroup();
   const previousActiveLoader = mediaType.activePlaylistLoader;
+  const lastTrack = mediaType.lastTrack_;
+
+  if (!lastTrack || (activeTrack && activeTrack.id !== lastTrack.id)) {
+    mediaType.lastTrack_ = activeTrack;
+  }
 
   stopLoaders(segmentLoader, mediaType);
 
@@ -149,6 +156,18 @@ export const onTrackChanged = (type, settings) => () => {
     return;
   }
 
+  if (activeGroup.masterPlaylist) {
+    if (activeTrack && lastTrack && activeTrack.id !== lastTrack.id) {
+      const mpc = settings.vhs.masterPlaylistController_;
+
+      mediaType.logger_(`track change. Switching master audio from ${lastTrack.id} to ${activeTrack.id}`);
+      masterPlaylistLoader.pause();
+      mainSegmentLoader.resetEverything();
+      mpc.fastQualityChange_();
+    }
+    return;
+  }
+
   if (type === 'AUDIO') {
     if (!activeGroup.playlistLoader) {
       // when switching from demuxed audio/video to muxed audio/video (noted by no
@@ -375,16 +394,19 @@ export const initialize = {
       sourceType,
       segmentLoaders: { [type]: segmentLoader },
       requestOptions,
-      master: { mediaGroups, playlists },
+      master: {mediaGroups},
       mediaTypes: {
         [type]: {
           groups,
-          tracks
+          tracks,
+          logger_
         }
       },
       masterPlaylistLoader
     } = settings;
 
+    const audioOnlyMaster = isAudioOnly(masterPlaylistLoader.master);
+
     // force a default if we have none
     if (!mediaGroups[type] ||
         Object.keys(mediaGroups[type]).length === 0) {
@@ -395,36 +417,19 @@ export const initialize = {
       if (!groups[groupId]) {
         groups[groupId] = [];
       }
-
-      // List of playlists that have an AUDIO attribute value matching the current
-      // group ID
-      const groupPlaylists = playlists.filter(playlist => {
-        return playlist.attributes[type] === groupId;
-      });
-
       for (const variantLabel in mediaGroups[type][groupId]) {
         let properties = mediaGroups[type][groupId][variantLabel];
 
-        // List of playlists for the current group ID that do not have a matching uri
-        // with this alternate audio variant
-        const unmatchingPlaylists = groupPlaylists.filter(playlist => {
-          return playlist.resolvedUri !== properties.resolvedUri;
-        });
-
-        // If there are no playlists using this audio group other than ones
-        // that match it's uri, then the playlist is audio only. We delete the resolvedUri
-        // property here to prevent a playlist loader from being created so that we don't have
-        // both the main and audio segment loaders loading the same audio segments
-        // from the same playlist.
-        if (!unmatchingPlaylists.length && groupPlaylists.length) {
-          delete properties.resolvedUri;
-        }
-
         let playlistLoader;
 
-        // if vhs-json was provided as the source, and the media playlist was resolved,
-        // use the resolved media playlist object
-        if (sourceType === 'vhs-json' && properties.playlists) {
+        if (audioOnlyMaster) {
+          logger_(`AUDIO group '${groupId}' label '${variantLabel}' is a master playlist`);
+          properties.masterPlaylist = true;
+          playlistLoader = null;
+
+          // if vhs-json was provided as the source, and the media playlist was resolved,
+          // use the resolved media playlist object
+        } else if (sourceType === 'vhs-json' && properties.playlists) {
           playlistLoader = new PlaylistLoader(
             properties.playlists[0],
             vhs,
@@ -658,17 +663,28 @@ export const activeGroup = (type, settings) => (track) => {
 
   let variants = null;
 
+  // set to variants to main media active group
   if (media.attributes[type]) {
     variants = groups[media.attributes[type]];
   }
 
-  variants = variants || groups.main;
+  const groupKeys = Object.keys(groups);
+
+  if (!variants && groupKeys.length === 1) {
+    // use the main group if it exists
+    if (groups.main) {
+      variants = groups.main;
+    // only one group, use that one
+    } else if (groupKeys.length === 1) {
+      variants = groups[groupKeys[0]];
+    }
+  }
 
   if (typeof track === 'undefined') {
     return variants;
   }
 
-  if (track === null) {
+  if (track === null || !variants) {
     // An active track was specified so a corresponding group is expected. track === null
     // means no track is currently active so there is no corresponding group
     return null;
@@ -767,6 +783,15 @@ export const setupMediaGroups = (settings) => {
     mediaTypes[type].onGroupChanged = onGroupChanged(type, settings);
     mediaTypes[type].onGroupChanging = onGroupChanging(type, settings);
     mediaTypes[type].onTrackChanged = onTrackChanged(type, settings);
+    mediaTypes[type].getActiveGroup = () => {
+      const activeTrack_ = mediaTypes[type].activeTrack();
+
+      if (!activeTrack_) {
+        return null;
+      }
+
+      return mediaTypes[type].activeGroup(activeTrack_);
+    };
   });
 
   // DO NOT enable the default subtitle or caption track.
@@ -777,6 +802,7 @@ export const setupMediaGroups = (settings) => {
     const groupId = (audioGroup.filter(group => group.default)[0] || audioGroup[0]).id;
 
     mediaTypes.AUDIO.tracks[groupId].enabled = true;
+    mediaTypes.AUDIO.onGroupChanged();
     mediaTypes.AUDIO.onTrackChanged();
   }
 
@@ -835,8 +861,11 @@ export const createMediaTypes = () => {
       activePlaylistLoader: null,
       activeGroup: noop,
       activeTrack: noop,
+      getActiveGroup: noop,
       onGroupChanged: noop,
-      onTrackChanged: noop
+      onTrackChanged: noop,
+      lastTrack_: null,
+      logger_: logger(`MediaGroups[${type}]`)
     };
   });
 

src/playlist-selectors.js

@@ -143,6 +143,8 @@ export const comparePlaylistResolution = function(left, right) {
  *        Current height of the player element (should account for the device pixel ratio)
  * @param {boolean} limitRenditionByPlayerDimensions
  *        True if the player width and height should be used during the selection, false otherwise
+ * @param {Playlist} [currentMedia]
+ *        The currently selected playlist if it exists.
  * @return {Playlist} the highest bitrate playlist less than the
  * currently detected bandwidth, accounting for some amount of
  * bandwidth variance
@@ -152,7 +154,8 @@ export const simpleSelector = function(
   playerBandwidth,
   playerWidth,
   playerHeight,
-  limitRenditionByPlayerDimensions
+  limitRenditionByPlayerDimensions,
+  masterPlaylistController
 ) {
 
   // If we end up getting called before `master` is available, exit early
@@ -166,8 +169,16 @@ export const simpleSelector = function(
     height: playerHeight,
     limitRenditionByPlayerDimensions
   };
+
+  let playlists = master.playlists;
+
+  // if playlist is audio only, select between currently active audio group playlists.
+  if (Playlist.isAudioOnly(master)) {
+    playlists = masterPlaylistController.getAudioTrackPlaylists_();
+    options.audioOnly = true;
+  }
   // convert the playlists to an intermediary representation to make comparisons easier
-  let sortedPlaylistReps = master.playlists.map((playlist) => {
+  let sortedPlaylistReps = playlists.map((playlist) => {
     let bandwidth;
     const width = playlist.attributes.RESOLUTION && playlist.attributes.RESOLUTION.width;
     const height = playlist.attributes.RESOLUTION && playlist.attributes.RESOLUTION.height;
@@ -320,7 +331,8 @@ export const lastBandwidthSelector = function() {
     this.systemBandwidth,
     parseInt(safeGetComputedStyle(this.tech_.el(), 'width'), 10) * pixelRatio,
     parseInt(safeGetComputedStyle(this.tech_.el(), 'height'), 10) * pixelRatio,
-    this.limitRenditionByPlayerDimensions
+    this.limitRenditionByPlayerDimensions,
+    this.masterPlaylistController_
   );
 };
 
@@ -358,7 +370,8 @@ export const movingAverageBandwidthSelector = function(decay) {
       average,
       parseInt(safeGetComputedStyle(this.tech_.el(), 'width'), 10) * pixelRatio,
       parseInt(safeGetComputedStyle(this.tech_.el(), 'height'), 10) * pixelRatio,
-      this.limitRenditionByPlayerDimensions
+      this.limitRenditionByPlayerDimensions,
+      this.masterPlaylistController_
     );
   };
 };

src/playlist.js

@@ -6,6 +6,7 @@
 import videojs from 'video.js';
 import window from 'global/window';
 import {TIME_FUDGE_FACTOR} from './ranges.js';
+import {isAudioCodec} from '@videojs/vhs-utils/es/codecs.js';
 
 const {createTimeRange} = videojs;
 
@@ -541,6 +542,26 @@ export const isLowestEnabledRendition = (master, media) => {
   }).length === 0);
 };
 
+export const isAudioOnly = (master) => {
+  // we are audio only if we have no main playlists but do
+  // have media group playlists.
+  if (!master.playlists.length) {
+    for (const groupName in master.mediaGroups.AUDIO) {
+      for (const label in master.mediaGroups.AUDIO[groupName]) {
+        const variant = master.mediaGroups.AUDIO[groupName][label];
+
+        if (variant.playlists && variant.playlists.length || variant.uri) {
+          return true;
+        }
+      }
+    }
+  }
+
+  return master.playlists
+    .every((p) => p.attributes && isAudioCodec(p.attributes.CODECS));
+
+};
+
 // exports
 export default {
   duration,
@@ -555,5 +576,6 @@ export default {
   isAes,
   hasAttribute,
   estimateSegmentRequestTime,
-  isLowestEnabledRendition
+  isLowestEnabledRendition,
+  isAudioOnly
 };