client: add MPV_EVENT_INITIALIZED

This may be useful for waiting until all scripts have finished loading.
Use with caution, as scripts shouldn't perform too many tasks during
initialization or afterward. Instead, they should wait to be triggered
by property or event changes.

DOCS/client-api-changes.rst

@@ -32,6 +32,8 @@ API changes
 
 ::
 
+ --- mpv 0.40.0 ---
+ 2.5    - add MPV_EVENT_INITIALIZED event
  --- mpv 0.39.0 ---
  2.4    - mpv_render_param with the MPV_RENDER_PARAM_ICC_PROFILE argument no
           longer has incorrect assumptions about memory allocation and can be

DOCS/man/input.rst

@@ -1722,6 +1722,10 @@ This list uses the event name field value, and the C API symbol in brackets:
     ``data``
         The new value of the property.
 
+``initialized`` (``MPV_EVENT_INITIALIZED``)
+    Triggered after initialization is complete, including all scripts.
+    mpv is proceeding to play the file.
+
 The following events also happen, but are deprecated: ``idle``, ``tick``
 Use ``mpv_observe_property()`` (Lua: ``mp.observe_property()``) instead.
 

libmpv/client.h

@@ -1368,6 +1368,11 @@ typedef enum mpv_event_id {
      * See also mpv_event and mpv_event_hook.
      */
     MPV_EVENT_HOOK              = 25,
+    /**
+     * Triggered after initialization is complete, including all scripts.
+     * mpv is proceeding to play the file.
+     */
+    MPV_EVENT_INITIALIZED       = 26,
     // Internal note: adjust INTERNAL_EVENT_BASE when adding new events.
 } mpv_event_id;
 

player/client.c

@@ -2114,6 +2114,7 @@ static const char *const event_table[] = {
     [MPV_EVENT_PROPERTY_CHANGE] = "property-change",
     [MPV_EVENT_QUEUE_OVERFLOW] = "event-queue-overflow",
     [MPV_EVENT_HOOK] = "hook",
+    [MPV_EVENT_INITIALIZED] = "initialized",
 };
 
 const char *mpv_event_name(mpv_event_id event)

player/loadfile.c

@@ -2015,6 +2015,7 @@ void mp_play_files(struct MPContext *mpctx)
     }
     // After above is finished; but even if it's skipped.
     mp_msg_set_early_logging(mpctx->global, false);
+    mp_notify(mpctx, MPV_EVENT_INITIALIZED, NULL);
 
     prepare_playlist(mpctx, mpctx->playlist);