Remove OPUS HLS streams from playable streams

This format is not supported by ExoPlayer when returned as HLS streams, so we
can't play streams using this format and this delivery method.

Also improve the Javadoc of ListHelper.getPlayableStreams.

app/src/main/java/org/schabi/newpipe/util/ListHelper.java

@@ -189,13 +189,16 @@ public static <S extends Stream> List<S> getUrlAndNonTorrentStreams(
 
     /**
      * Return a {@link Stream} list which only contains streams which can be played by the player.
-     * <br>
-     * Some formats are not supported. For more info, see {@link #SUPPORTED_ITAG_IDS}.
-     * Torrent streams are also removed, because they cannot be retrieved.
+     *
+     * <p>
+     * Some formats are not supported, see {@link #SUPPORTED_ITAG_IDS} for more details.
+     * Torrent streams are also removed, because they cannot be retrieved, like OPUS streams using
+     * HLS as their delivery method, since they are not supported by ExoPlayer.
+     * </p>
      *
      * @param <S>        the item type's class that extends {@link Stream}
      * @param streamList the original stream list
-     * @param serviceId
+     * @param serviceId  the service ID from which the streams' list comes from
      * @return a stream list which only contains streams that can be played the player
      */
     @NonNull
@@ -204,6 +207,8 @@ public static <S extends Stream> List<S> getPlayableStreams(
         final int youtubeServiceId = YouTube.getServiceId();
         return getFilteredStreamList(streamList,
                 stream -> stream.getDeliveryMethod() != DeliveryMethod.TORRENT
+                        && (stream.getDeliveryMethod() != DeliveryMethod.HLS
+                        || stream.getFormat() != MediaFormat.OPUS)
                         && (serviceId != youtubeServiceId
                         || stream.getItagItem() == null
                         || SUPPORTED_ITAG_IDS.contains(stream.getItagItem().id)));
@@ -295,7 +300,9 @@ public static List<AudioStream> getFilteredAudioStreams(
         final Comparator<AudioStream> cmp = getAudioFormatComparator(context);
 
         for (final AudioStream stream : audioStreams) {
-            if (stream.getDeliveryMethod() == DeliveryMethod.TORRENT) {
+            if (stream.getDeliveryMethod() == DeliveryMethod.TORRENT
+                    || (stream.getDeliveryMethod() == DeliveryMethod.HLS
+                    && stream.getFormat() == MediaFormat.OPUS)) {
                 continue;
             }