VAAPI-X11: adjust subpicture cache refcounting

Do refcounting when the subpicture is actually attached to the picture,
thus only in SubpictureRegionsLink() and SubpictureRegionsUnlink() functions

modules/codec/avcodec/vaapi_x11.c

@@ -813,6 +813,7 @@ static int SubpictureRegionsLink(vout_display_t *vd, const picture_t *picture)
         i_sub++;
     }
 
+    cache_ref(cache);
     vlc_mutex_unlock(&sys->cache_lock);
     return VLC_SUCCESS;
 
@@ -845,8 +846,8 @@ error:
 static void SubpictureRegionsUnlink(vout_display_t *vd, picture_t *picture)
 {
     vout_display_sys_t *sys = vd->sys;
-
     picture_sys_t *surface = picture->p_sys;
+
     assert(surface);
     assert(surface->i_id != VA_INVALID_SURFACE);
 
@@ -858,6 +859,10 @@ static void SubpictureRegionsUnlink(vout_display_t *vd, picture_t *picture)
 
     assert(cache->i_id != VA_INVALID_ID);
 
+#ifdef VAAPI_DEBUG
+        msg_Dbg(vd, "unlink surface %d cache %d", surface->i_id, surface->i_cache);
+#endif
+
     const int count = vlc_array_count(&cache->subpictures);
     for (int i = 0; i < count; i++)
     {
@@ -879,6 +884,20 @@ static void SubpictureRegionsUnlink(vout_display_t *vd, picture_t *picture)
         }
     }
 
+    cache_unref(cache);
+
+    /* Do we still need need this subpicture cache ? */
+    if ((cache->i_refcount == 0) &&
+        (sys->render.i_cache != surface->i_cache) &&
+        (mdate() > cache->i_stop))
+    {
+        int index = vlc_array_index_of_item(&sys->cache, (void*)cache);
+        vlc_array_remove(&sys->cache, index);
+        SubpictureCacheClean(vd, sys->conn, cache);
+        cache_destroy(cache);
+        cache = NULL;
+    }
+
 error:
     vlc_mutex_unlock(&sys->cache_lock);
 }
@@ -1084,7 +1103,7 @@ static int RenderDirectSubpicture(vout_display_t *vd, picture_t *picture, subpic
     /* remember what was created, so it can be released in DisplayPicture() */
     vlc_mutex_lock(&sys->cache_lock);
     vlc_array_append(&sys->cache, (void *)cache);
-    cache_ref(cache);
+    //cache_ref(cache);
     sys->render.i_cache = cache->i_id;
     surface->i_cache = cache->i_id;
     vlc_mutex_unlock(&sys->cache_lock);
@@ -1169,7 +1188,7 @@ static int RenderCachedSubpictures(vout_display_t *vd, picture_t *picture,
         goto cleanup;
 
     picture->p_sys->i_cache = cache->i_id;
-    cache_ref(cache);
+    //cache_ref(cache);
     vlc_mutex_unlock(&sys->cache_lock);
     return VLC_SUCCESS;
 
@@ -1270,6 +1289,8 @@ static void PictureRelease(picture_t *picture)
             vlc_mutex_unlock(&vd->sys->cache_lock);
         }
 
+        surface->i_cache = VA_INVALID_ID;
+
         /* */
         vd->sys->conn->lock();
         vaDestroySurfaces(vd->sys->conn->p_display, &picture->p_sys->i_id, 1);
@@ -1363,11 +1384,12 @@ static void PictureUnlock(picture_t *picture)
     if (surface == NULL)
         return;
 
-    vout_display_t *vd = (vout_display_t*) picture->p_sys->obj;
-    vout_display_sys_t *sys = (vout_display_sys_t *) vd->sys;
-
+#if 0
     if (surface->i_cache != VA_INVALID_ID)
     {
+        vout_display_t *vd = (vout_display_t*) picture->p_sys->obj;
+        vout_display_sys_t *sys = (vout_display_sys_t *) vd->sys;
+
         vlc_mutex_lock(&sys->cache_lock);
 #ifdef VAAPI_DEBUG
         msg_Dbg(vd, "unlink surface %d cache %d", surface->i_id, surface->i_cache);
@@ -1391,7 +1413,7 @@ static void PictureUnlock(picture_t *picture)
         }
         vlc_mutex_unlock(&sys->cache_lock);
     }
-
+#endif
     /* */
     if (surface->i_refcount > 0)
         surface->i_refcount--;