libobs: Add functions to get total/lagged frames

Useful for rendering statistics.

libobs/obs.c

@@ -1957,3 +1957,13 @@ void obs_remove_main_render_callback(
 	da_erase_item(obs->data.draw_callbacks, &data);
 	pthread_mutex_unlock(&obs->data.draw_callbacks_mutex);
 }
+
+uint32_t obs_get_total_frames(void)
+{
+	return obs ? obs->video.total_frames : 0;
+}
+
+uint32_t obs_get_lagged_frames(void)
+{
+	return obs ? obs->video.lagged_frames : 0;
+}

libobs/obs.h

@@ -629,6 +629,9 @@ EXPORT uint64_t obs_get_video_frame_time(void);
 EXPORT double obs_get_active_fps(void);
 EXPORT uint64_t obs_get_average_frame_time_ns(void);
 
+EXPORT uint32_t obs_get_total_frames(void);
+EXPORT uint32_t obs_get_lagged_frames(void);
+
 
 /* ------------------------------------------------------------------------- */
 /* Display context */