clapper-app: Apply "adaptive-start-bitrate" on startup

Watch for "adaptive-bandwidth" changes during adaptive streaming, use these to
set "adaptive-start-bitrate" player property, so we do not always start streaming
from some constant bitrate value which might not be the best for everyone.

Additionally, store last value in GSettings on app exit and also add a command
line arg to set this too.

src/bin/clapper-app/clapper-app-application.c

@@ -144,6 +144,8 @@ clapper_app_apply_options_to_window (ClapperAppWindow *dest_window, GVariantDict
     clapper_player_set_mute (dest_player, option_bool);
   if (clapper_app_options_get ("speed", "d", options, src_player_obj, settings, &option_dbl))
     clapper_player_set_speed (dest_player, PERCENTAGE_ROUND (CLAMP (option_dbl, 0.05, 2.0)));
+  if (clapper_app_options_get ("adaptive-start-bitrate", "i", options, src_player_obj, settings, &option_int))
+    clapper_player_set_adaptive_start_bitrate (dest_player, option_int);
   if (clapper_app_options_get ("progression-mode", "i", options, src_queue_obj, settings, &option_int))
     clapper_queue_set_progression_mode (clapper_player_get_queue (dest_player), CLAMP (option_int, 0, 4));
   if (clapper_app_options_get ("subtitles-enabled", "b", NULL, src_player_obj, settings, &option_bool))
@@ -196,6 +198,8 @@ _store_settings_from_window (ClapperAppApplication *self, ClapperAppWindow *app_
   g_settings_set_double (self->settings, "volume", clapper_player_get_volume (player));
   g_settings_set_boolean (self->settings, "mute", clapper_player_get_mute (player));
   g_settings_set_double (self->settings, "speed", clapper_player_get_speed (player));
+  g_settings_set_int (self->settings, "adaptive-start-bitrate",
+      CLAMP (clapper_player_get_adaptive_bandwidth (player) * 0.8, 0, G_MAXINT));
   g_settings_set_boolean (self->settings, "subtitles-enabled", clapper_player_get_subtitles_enabled (player));
   g_settings_set_int (self->settings, "progression-mode", clapper_queue_get_progression_mode (queue));
 
@@ -676,6 +680,7 @@ clapper_app_application_constructed (GObject *object)
     { "enqueue", 0, 0, G_OPTION_ARG_NONE, NULL, _("Add media to queue in primary application instance"), NULL },
     { "volume", 0, 0, G_OPTION_ARG_DOUBLE, NULL, _("Audio volume to set (0 - 2.0 range)"), NULL },
     { "speed", 0, 0, G_OPTION_ARG_DOUBLE, NULL, _("Playback speed to set (0.05 - 2.0 range)"), NULL },
+    { "adaptive-start-bitrate", 0, 0, G_OPTION_ARG_INT, NULL, _("Initial bitrate for adaptive streaming"), NULL },
     { "progression-mode", 0, 0, G_OPTION_ARG_INT, NULL, _("Initial queue progression mode (0=none, 1=consecutive, 2=repeat-item, 3=carousel, 4=shuffle)"), NULL },
     { "fullscreen", 'f', 0, G_OPTION_ARG_NONE, NULL, _("Set window to be fullscreen"), NULL },
     { "video-filter", 0, 0, G_OPTION_ARG_STRING, NULL, _("Video filter to use (\"none\" to disable)"), NULL },

src/bin/clapper-app/clapper-app-window.c

@@ -151,6 +151,15 @@ _queue_current_item_changed_cb (ClapperQueue *queue,
   gst_clear_object (&current_item);
 }
 
+static void
+_player_adaptive_bandwidth_changed_cb (ClapperPlayer *player,
+    GParamSpec *pspec G_GNUC_UNUSED, gpointer *user_data G_GNUC_UNUSED)
+{
+  /* Do not take whole bandwidth */
+  clapper_player_set_adaptive_start_bitrate (player,
+      clapper_player_get_adaptive_bandwidth (player) * 0.8);
+}
+
 static gboolean
 _get_seek_method_mapping (GValue *value,
     GVariant *variant, gpointer user_data G_GNUC_UNUSED)
@@ -1280,10 +1289,12 @@ clapper_app_window_constructed (GObject *object)
 
   clapper_player_set_autoplay (player, TRUE);
 
-  /* No need to also call this here, as item is selected
+  /* No need to also call these here, as they only change
    * after application window is contructed */
   g_signal_connect (queue, "notify::current-item",
       G_CALLBACK (_queue_current_item_changed_cb), self);
+  g_signal_connect (player, "notify::adaptive-bandwidth",
+      G_CALLBACK (_player_adaptive_bandwidth_changed_cb), NULL);
 
   g_settings_bind (self->settings, "audio-offset",
       player, "audio-offset", G_SETTINGS_BIND_GET);

src/bin/clapper-app/data/glib-2.0/schemas/com.github.rafostar.Clapper.gschema.xml

@@ -49,6 +49,10 @@
       <default>1.0</default>
       <summary>Stores last speed value to apply on startup</summary>
     </key>
+    <key name="adaptive-start-bitrate" type="i">
+      <default>1600000</default>
+      <summary>Stores initial adaptive streaming bitrate to apply on startup</summary>
+    </key>
     <key name="progression-mode" type="i">
       <default>1</default>
       <summary>Stores last queue progression mode used to apply on startup</summary>