subs, vo: do sub bitmap change detection by comparing IDs

vo_vdpau and vo_gl cache the last subtitle bitmaps uploaded to video
card in case they stay the same over multiple frames. Detecting
whether the bitmaps have changed and should be re-uploaded was
somewhat fragile. Change the VO API to provide a bitmap ID which can
be compared with what the VO has to determine whether a new upload of
the bitmaps is needed.

Conflicts:
	libvo/vo_gl.c

Note: the changes for vo_gl.c were not merged. Instead, eosd_packer is
modified to use the new way of detecting EOSD changes. This takes care
of vo_gl, vo_gl3 and vo_direct3d, which all render EOSD. They don't
need to be updated in turn.

1 files changed, 1 insertions, 15 deletions

diff --git a/libmpcodecs/vf_vo.c b/libmpcodecs/vf_vo.c
index 076850c8c2..3aec40cd15 100644
--- a/libmpcodecs/vf_vo.c
+++ b/libmpcodecs/vf_vo.c
@@ -34,7 +34,6 @@
 
 struct vf_priv_s {
     struct vo *vo;
-    bool prev_visibility;
     double scale_ratio;
 };
 #define video_out (vf->priv->vo)
@@ -77,9 +76,6 @@ static int config(struct vf_instance *vf,
 
     vf->priv->scale_ratio = (double) d_width / d_height * height / width;
 
-    // force EOSD change detection reset
-    vf->priv->prev_visibility = false;
-
     return 1;
 }
 
@@ -121,27 +117,17 @@ static int control(struct vf_instance *vf, int request, void *data)
         };
         return vo_control(video_out, VOCTRL_GET_EQUALIZER, &param) == VO_TRUE;
     }
-    case VFCTRL_INIT_EOSD: {
-        vf->priv->prev_visibility = false;
-        return CONTROL_TRUE;
-    }
-
     case VFCTRL_DRAW_EOSD: {
         struct osd_state *osd = data;
         osd->dim = (struct mp_eosd_res){0};
         if (!video_out->config_ok ||
-                vo_control(video_out, VOCTRL_GET_EOSD_RES, &osd->dim) != true) {
-            vf->priv->prev_visibility = false;
+                vo_control(video_out, VOCTRL_GET_EOSD_RES, &osd->dim) != true)
             return CONTROL_FALSE;
-        }
         osd->normal_scale = 1;
         osd->vsfilter_scale = vf->priv->scale_ratio;
         osd->unscaled = vf->default_caps & VFCAP_EOSD_UNSCALED;
         struct sub_bitmaps images;
         sub_get_bitmaps(osd, &images);
-        if (!vf->priv->prev_visibility)
-            images.changed = 2;
-        vf->priv->prev_visibility = true;
         return vo_control(video_out, VOCTRL_DRAW_EOSD, &images) == VO_TRUE;
     }
     }