vo: generic redraw support

Usually, a VO must react to VOCTRL_REDRAW_FRAME in order to redraw the
current screen correctly if video is paused (this is done to update
OSD). But if it's not supported, we can just draw the current image
again in the generic vo.c code.

Unfortunately, this turned out pretty useless, because the VOs which
would benefit from this need to redraw even if there is no image, in
order to draw a black screen in --idle --force-window mode. The way
redrawing is handled in the X11 common code and in vo_x11 and vo_xv is
in the way, and I'm not sure what exactly vo_wayland requires. Other VOs
have a non-trivial implementation of VOCTRL_REDRAW_FRAME, which
(probably) makes redrawing slightly more efficient, e.g. by skipping
texture upload. So for now, no VO uses this new functionality, but since
it's trivial, commit it anyway.

The vo_driver->untimed case is for forcibly disabling redraw for vo_lavc
and vo_image always.

1 files changed, 3 insertions, 5 deletions

diff --git a/video/out/vo.c b/video/out/vo.c
index 11690afb67..aee2dd8c75 100644
--- a/video/out/vo.c
+++ b/video/out/vo.c
@@ -687,9 +687,9 @@ static void do_redraw(struct vo *vo)
     pthread_mutex_lock(&in->lock);
     in->request_redraw = false;
     in->want_redraw = false;
-    bool force_full_redraw = in->dropped_frame;
+    bool full_redraw = in->dropped_frame;
     struct mp_image *img = NULL;
-    if (vo->config_ok)
+    if (vo->config_ok && !(vo->driver->untimed))
         img = mp_image_new_ref(in->current_frame);
     if (img)
         in->dropped_frame = false;
@@ -698,12 +698,10 @@ static void do_redraw(struct vo *vo)
     if (!img)
         return;
 
-    if (force_full_redraw) {
+    if (full_redraw || vo->driver->control(vo, VOCTRL_REDRAW_FRAME, NULL) < 1) {
         vo->driver->draw_image(vo, img);
     } else {
         talloc_free(img);
-        if (vo->driver->control(vo, VOCTRL_REDRAW_FRAME, NULL) < 1)
-            return;
     }
 
     if (vo->driver->flip_page_timed)