hlsdemux: Reload the variant playlist if refreshing a playlist or downloading a fragment fails

This can happen if the playlists have moved due to the variant playlist
now being redirected to another target. This currently only works as long
as the referenced playlists don't change in relation to the variant
playlist, and the new location is purely due to a new path triggered by a
new redirection target of the variant playlist, or a new redirection
target of the playlist itself.

https://bugzilla.gnome.org/show_bug.cgi?id=731164

1 files changed, 180 insertions, 5 deletions

diff --git a/ext/hls/m3u8.c b/ext/hls/m3u8.c
index d66da2d47..40ce09027 100644
--- a/ext/hls/m3u8.c
+++ b/ext/hls/m3u8.c
@@ -50,7 +50,7 @@ gst_m3u8_new (void)
 }
 
 static void
-gst_m3u8_set_uri (GstM3U8 * self, gchar * uri, gchar * base_uri)
+gst_m3u8_set_uri (GstM3U8 * self, gchar * uri, gchar * base_uri, gchar * name)
 {
   g_return_if_fail (self != NULL);
 
@@ -59,6 +59,9 @@ gst_m3u8_set_uri (GstM3U8 * self, gchar * uri, gchar * base_uri)
 
   g_free (self->base_uri);
   self->base_uri = base_uri;
+
+  g_free (self->name);
+  self->name = name;
 }
 
 static void
@@ -68,6 +71,7 @@ gst_m3u8_free (GstM3U8 * self)
 
   g_free (self->uri);
   g_free (self->base_uri);
+  g_free (self->name);
   g_free (self->codecs);
   g_free (self->key);
 
@@ -109,6 +113,85 @@ gst_m3u8_media_file_free (GstM3U8MediaFile * self)
   g_free (self);
 }
 
+static GstM3U8MediaFile *
+gst_m3u8_media_file_copy (const GstM3U8MediaFile * self, gpointer user_data)
+{
+  g_return_if_fail (self != NULL);
+
+  return gst_m3u8_media_file_new (g_strdup (self->uri), g_strdup (self->title),
+      self->duration, self->sequence);
+}
+
+static GstM3U8 *
+_m3u8_copy (const GstM3U8 * self, GstM3U8 * parent)
+{
+  GstM3U8 *dup;
+
+  g_return_if_fail (self != NULL);
+
+  dup = gst_m3u8_new ();
+  dup->uri = g_strdup (self->uri);
+  dup->base_uri = g_strdup (self->base_uri);
+  dup->name = g_strdup (self->name);
+  dup->endlist = self->endlist;
+  dup->version = self->version;
+  dup->targetduration = self->targetduration;
+  dup->allowcache = self->allowcache;
+  dup->key = g_strdup (self->key);
+  dup->bandwidth = self->bandwidth;
+  dup->program_id = self->program_id;
+  dup->codecs = g_strdup (self->codecs);
+  dup->width = self->width;
+  dup->height = self->height;
+  dup->iframe = self->iframe;
+  dup->files =
+      g_list_copy_deep (self->files, (GCopyFunc) gst_m3u8_media_file_copy,
+      NULL);
+
+  /* private */
+  dup->last_data = g_strdup (self->last_data);
+  dup->lists = g_list_copy_deep (self->lists, (GCopyFunc) _m3u8_copy, dup);
+  dup->iframe_lists =
+      g_list_copy_deep (self->iframe_lists, (GCopyFunc) _m3u8_copy, dup);
+  /* NOTE: current_variant will get set in gst_m3u8_copy () */
+  dup->parent = parent;
+  dup->mediasequence = self->mediasequence;
+  return dup;
+}
+
+static GstM3U8 *
+gst_m3u8_copy (const GstM3U8 * self)
+{
+  GList *entry;
+  guint n;
+
+  GstM3U8 *dup = _m3u8_copy (self, NULL);
+
+  if (self->current_variant != NULL) {
+    for (n = 0, entry = self->lists; entry; entry = entry->next, n++) {
+      if (entry == self->current_variant) {
+        dup->current_variant = g_list_nth (dup->lists, n);
+        break;
+      }
+    }
+
+    if (!dup->current_variant) {
+      for (n = 0, entry = self->iframe_lists; entry; entry = entry->next, n++) {
+        if (entry == self->current_variant) {
+          dup->current_variant = g_list_nth (dup->iframe_lists, n);
+          break;
+        }
+      }
+
+      if (!dup->current_variant) {
+        GST_ERROR ("Failed to determine current playlist");
+      }
+    }
+  }
+
+  return dup;
+}
+
 static gboolean
 int_from_string (gchar * ptr, gchar ** endptr, gint * val)
 {
@@ -320,6 +403,7 @@ gst_m3u8_update (GstM3U8 * self, gchar * data, gboolean * updated)
       *r = '\0';
 
     if (data[0] != '#' && data[0] != '\0') {
+      gchar *name = data;
       if (duration <= 0 && list == NULL) {
         GST_LOG ("%s: got line without EXTINF or EXTSTREAMINF, dropping", data);
         goto next_line;
@@ -336,7 +420,7 @@ gst_m3u8_update (GstM3U8 * self, gchar * data, gboolean * updated)
           gst_m3u8_free (list);
           g_free (data);
         } else {
-          gst_m3u8_set_uri (list, data, NULL);
+          gst_m3u8_set_uri (list, data, NULL, g_strdup (name));
           self->lists = g_list_append (self->lists, list);
         }
         list = NULL;
@@ -397,6 +481,7 @@ gst_m3u8_update (GstM3U8 * self, gchar * data, gboolean * updated)
       GstM3U8 *new_list;
 
       new_list = gst_m3u8_new ();
+      new_list->parent = self;
       new_list->iframe = iframe;
       data = data + (iframe ? 26 : 18);
       while (data && parse_attributes (&data, &a, &v)) {
@@ -420,6 +505,7 @@ gst_m3u8_update (GstM3U8 * self, gchar * data, gboolean * updated)
               GST_WARNING ("Error while reading RESOLUTION height");
           }
         } else if (iframe && g_str_equal (a, "URI")) {
+          gchar *name;
           gchar *uri = g_strdup (v);
           gchar *urip = uri;
           int len = strlen (uri);
@@ -430,12 +516,15 @@ gst_m3u8_update (GstM3U8 * self, gchar * data, gboolean * updated)
           if (uri[0] == '"')
             uri += 1;
 
+          name = g_strdup (uri);
           uri = uri_join (self->base_uri ? self->base_uri : self->uri, uri);
           g_free (urip);
 
-          if (uri == NULL)
+          if (uri == NULL) {
+            g_free (name);
             continue;
-          gst_m3u8_set_uri (new_list, uri, NULL);
+          }
+          gst_m3u8_set_uri (new_list, uri, NULL, name);
         }
       }
 
@@ -620,7 +709,7 @@ gst_m3u8_client_new (const gchar * uri, const gchar * base_uri)
   client->sequence_position = 0;
   client->update_failed_count = 0;
   g_mutex_init (&client->lock);
-  gst_m3u8_set_uri (client->main, g_strdup (uri), g_strdup (base_uri));
+  gst_m3u8_set_uri (client->main, g_strdup (uri), g_strdup (base_uri), NULL);
 
   return client;
 }
@@ -695,6 +784,92 @@ out:
   return ret;
 }
 
+static gint
+_find_m3u8_list_match (const GstM3U8 * a, const GstM3U8 * b)
+{
+  if (g_strcmp0 (a->name, b->name) == 0 &&
+      a->bandwidth == b->bandwidth &&
+      a->program_id == b->program_id &&
+      g_strcmp0 (a->codecs, b->codecs) == 0 &&
+      a->width == b->width &&
+      a->height == b->height && a->iframe == b->iframe) {
+    return 0;
+  }
+
+  return 1;
+}
+
+gboolean
+gst_m3u8_client_update_variant_playlist (GstM3U8Client * self, gchar * data,
+    const gchar * uri, const gchar * base_uri)
+{
+  gboolean ret = FALSE;
+  GList *list_entry, *unmatched_lists;
+  GstM3U8Client *new_client;
+  GstM3U8 *old;
+
+  g_return_val_if_fail (self != NULL, FALSE);
+
+  new_client = gst_m3u8_client_new (uri, base_uri);
+  if (gst_m3u8_client_update (new_client, data)) {
+    if (!new_client->main->lists) {
+      GST_ERROR
+          ("Cannot update variant playlist: New playlist is not a variant playlist");
+      gst_m3u8_client_free (new_client);
+      return FALSE;
+    }
+
+    GST_M3U8_CLIENT_LOCK (self);
+
+    if (!self->main->lists) {
+      GST_ERROR
+          ("Cannot update variant playlist: Current playlist is not a variant playlist");
+      goto out;
+    }
+
+    /* Now see if the variant playlist still has the same lists */
+    unmatched_lists = g_list_copy (self->main->lists);
+    for (list_entry = new_client->main->lists; list_entry;
+        list_entry = list_entry->next) {
+      GList *match = g_list_find_custom (unmatched_lists, list_entry->data,
+          (GCompareFunc) _find_m3u8_list_match);
+      if (match)
+        unmatched_lists = g_list_remove_link (unmatched_lists, match);
+    }
+
+    if (unmatched_lists != NULL) {
+      g_list_free (unmatched_lists);
+
+      /* We should attempt to handle the case where playlists are dropped/replaced,
+       * and possibly switch over to a comparable (not neccessarily identical)
+       * playlist.
+       */
+      GST_FIXME
+          ("Cannot update variant playlist, unable to match all playlists");
+      goto out;
+    }
+
+    /* Switch out the variant playlist */
+    old = self->main;
+
+    self->main = gst_m3u8_copy (new_client->main);
+    if (self->main->lists)
+      self->current = self->main->current_variant->data;
+    else
+      self->current = self->main;
+
+    gst_m3u8_free (old);
+
+    ret = TRUE;
+
+  out:
+    GST_M3U8_CLIENT_UNLOCK (self);
+  }
+
+  gst_m3u8_client_free (new_client);
+  return ret;
+}
+
 static gboolean
 _find_current (GstM3U8MediaFile * file, GstM3U8Client * client)
 {