hlsdemux: Choose the default variant and track it when updating

Modify playlist updating to track information across updates
better, although still hackish.

When connection_speed == 0, choose the default variant
not the first one in the (now sorted) variant list, as that
will have the lowest bitrate.

ext/hls/gsthlsdemux.c

@@ -462,20 +462,37 @@ gst_hls_demux_set_current_variant (GstHLSDemux * hlsdemux,
     return;
 
   if (hlsdemux->current_variant != NULL) {
+    gint i;
+
     //#warning FIXME: Synching fragments across variants
     //  should be done based on media timestamps, and
     //  discont-sequence-numbers not sequence numbers.
     variant->m3u8->sequence_position =
         hlsdemux->current_variant->m3u8->sequence_position;
     variant->m3u8->sequence = hlsdemux->current_variant->m3u8->sequence;
-    variant->m3u8->highest_sequence_number =
-        hlsdemux->current_variant->m3u8->highest_sequence_number;
 
     GST_DEBUG_OBJECT (hlsdemux,
         "Switching Variant. Copying over sequence %" G_GINT64_FORMAT
         " and sequence_pos %" GST_TIME_FORMAT, variant->m3u8->sequence,
         GST_TIME_ARGS (variant->m3u8->sequence_position));
 
+    for (i = 0; i < GST_HLS_N_MEDIA_TYPES; ++i) {
+      GList *mlist = hlsdemux->current_variant->media[i];
+
+      while (mlist != NULL) {
+        GstHLSMedia *old_media = mlist->data;
+        GstHLSMedia *new_media =
+            gst_hls_variant_find_matching_media (variant, old_media);
+
+        if (new_media) {
+          new_media->playlist->sequence = old_media->playlist->sequence;
+          new_media->playlist->sequence_position =
+              old_media->playlist->sequence_position;
+        }
+        mlist = mlist->next;
+      }
+    }
+
     gst_hls_variant_stream_unref (hlsdemux->current_variant);
   }
 
@@ -513,7 +530,7 @@ gst_hls_demux_process_manifest (GstAdaptiveDemux * demux, GstBuffer * buf)
 
   /* select the initial variant stream */
   if (demux->connection_speed == 0) {
-    variant = hlsdemux->master->variants->data;
+    variant = hlsdemux->master->default_variant;
   } else {
     variant =
         gst_hls_master_playlist_get_variant_for_bitrate (hlsdemux->master,
@@ -908,6 +925,9 @@ gst_hls_demux_update_fragment_info (GstAdaptiveDemuxStream * stream)
 
   g_free (stream->fragment.uri);
   stream->fragment.uri = g_strdup (file->uri);
+
+  GST_DEBUG_OBJECT (stream, "URI now %s", file->uri);
+
   stream->fragment.range_start = file->offset;
   if (file->size != -1)
     stream->fragment.range_end = file->offset + file->size - 1;
@@ -1012,10 +1032,13 @@ gst_hls_demux_update_variant_playlist (GstHLSDemux * hlsdemux, gchar * data,
   GstHLSMasterPlaylist *new_master, *old;
   gboolean ret = FALSE;
   GList *l, *unmatched_lists;
+  GstHLSVariantStream *new_variant;
 
   new_master = gst_hls_master_playlist_new_from_data (data, base_uri ? base_uri : uri); // FIXME: check which uri to use here
 
-  if (new_master != NULL) {
+  if (new_master == NULL)
+    return ret;
+
   if (new_master->is_simple) {
     // FIXME: we should be able to support this though, in the unlikely
     // case that it changed?
@@ -1038,10 +1061,15 @@ gst_hls_demux_update_variant_playlist (GstHLSDemux * hlsdemux, gchar * data,
   for (l = new_master->variants; l != NULL; l = l->next) {
     GList *match = g_list_find_custom (unmatched_lists, l->data,
         (GCompareFunc) gst_hls_demux_find_variant_match);
+
     if (match) {
+      GstHLSVariantStream *variant = l->data;
+      GstHLSVariantStream *old = match->data;
+
       unmatched_lists = g_list_delete_link (unmatched_lists, match);
-        // FIXME: copy over state variables of playlist, or keep old instance
+      /* FIXME: Deal with losing position due to missing an update */
-        GST_ERROR ("FIXME: copy over state variables of playlist");
+      variant->m3u8->sequence_position = old->m3u8->sequence_position;
+      variant->m3u8->sequence = old->m3u8->sequence;
     }
   }
 
@@ -1057,21 +1085,30 @@ gst_hls_demux_update_variant_playlist (GstHLSDemux * hlsdemux, gchar * data,
     g_list_free (unmatched_lists);
   }
 
-    /* Switch out the variant playlist, steal it from new_client */
+  /* Switch out the variant playlist */
   old = hlsdemux->master;
 
   // FIXME: check all this and also switch of variants, if anything needs updating
   hlsdemux->master = new_master;
 
-    hlsdemux->current_variant = hlsdemux->master->default_variant;
+  if (hlsdemux->current_variant == NULL) {
+    new_variant = new_master->default_variant;
+  } else {
+    /* Find the same variant in the new playlist */
+    new_variant =
+        gst_hls_master_playlist_get_matching_variant (new_master,
+        hlsdemux->current_variant);
+  }
+
+  /* Use the function to set the current variant, as it copies over data */
+  if (new_variant != NULL)
+    gst_hls_demux_set_current_variant (hlsdemux, new_variant);
 
   gst_hls_master_playlist_unref (old);
 
-    ret = TRUE;
+  ret = (hlsdemux->current_variant != NULL);
-
 out:
   GST_M3U8_CLIENT_UNLOCK (self);
-  }
 
   return ret;
 }

ext/hls/m3u8.c

@@ -1552,6 +1552,29 @@ gst_hls_variant_stream_is_live (GstHLSVariantStream * variant)
   return is_live;
 }
 
+static gint
+compare_media (const GstHLSMedia * a, const GstHLSMedia * b)
+{
+  return strcmp (a->name, b->name);
+}
+
+GstHLSMedia *
+gst_hls_variant_find_matching_media (GstHLSVariantStream * stream,
+    GstHLSMedia * media)
+{
+  GList *mlist = stream->media[media->mtype];
+  GList *match;
+
+  if (mlist == NULL)
+    return NULL;
+
+  match = g_list_find_custom (mlist, media, (GCompareFunc) compare_media);
+  if (match == NULL)
+    return NULL;
+
+  return match->data;
+}
+
 GstHLSVariantStream *
 gst_hls_master_playlist_get_variant_for_bitrate (GstHLSMasterPlaylist *
     playlist, GstHLSVariantStream * current_variant, guint bitrate)
@@ -1574,3 +1597,15 @@ gst_hls_master_playlist_get_variant_for_bitrate (GstHLSMasterPlaylist *
 
   return variant;
 }
+
+GstHLSVariantStream *
+gst_hls_master_playlist_get_matching_variant (GstHLSMasterPlaylist * playlist,
+    GstHLSVariantStream * current_variant)
+{
+  if (current_variant->iframe) {
+    return find_variant_stream_by_uri (playlist->iframe_variants,
+        current_variant->uri);
+  }
+
+  return find_variant_stream_by_uri (playlist->variants, current_variant->uri);
+}

ext/hls/m3u8.h

@@ -193,6 +193,9 @@ void                  gst_hls_variant_stream_unref (GstHLSVariantStream * stream
 
 gboolean              gst_hls_variant_stream_is_live (GstHLSVariantStream * stream);
 
+GstHLSMedia *         gst_hls_variant_find_matching_media (GstHLSVariantStream  * stream,
+                          GstHLSMedia *media);
+
 
 struct _GstHLSMasterPlaylist
 {
@@ -220,6 +223,8 @@ GstHLSMasterPlaylist * gst_hls_master_playlist_new_from_data (gchar       * data
 GstHLSVariantStream *  gst_hls_master_playlist_get_variant_for_bitrate (GstHLSMasterPlaylist * playlist,
                                                                         GstHLSVariantStream  * current_variant,
                                                                         guint                  bitrate);
+GstHLSVariantStream *  gst_hls_master_playlist_get_matching_variant (GstHLSMasterPlaylist * playlist,
+                                                                     GstHLSVariantStream  * current_variant);
 
 void                   gst_hls_master_playlist_unref (GstHLSMasterPlaylist * playlist);