various: make --osd/sub-scale-by-window options only scale upwards

These options keep text readable whether you use a small screen near you
or a faraway large screen, but they make it unreadable in small windows,
so change them to only scale upwards, i.e. when the window height is >
720.

DOCS/man/options.rst

@@ -2425,9 +2425,9 @@ Subtitles
         rendering. Use with care, or use ``--sub-font-size`` instead.
 
 ``--sub-scale-by-window=<yes|no>``
-    Whether to scale subtitles with the window size (default: yes). If this is
-    disabled while ``--sub-scale-with-window`` is set to yes, changing the window
-    size won't change the subtitle font size.
+    Whether to scale subtitles with the window height when it is taller than 720
+    pixels (default: yes). If this is disabled while ``--sub-scale-with-window``
+    is set to yes, changing the window size won't change the subtitle font size.
 
     Affects plain text subtitles only (or ASS if ``--sub-ass-override`` is set
     high enough).
@@ -4585,10 +4585,10 @@ OSD
     OSD font size multiplier, multiplied with ``--osd-font-size`` value.
 
 ``--osd-scale-by-window=<yes|no>``
-    Whether to scale the OSD with the window size (default: yes). If this is
-    disabled, ``--osd-font-size`` and other OSD options that use scaled pixels
-    are always in actual pixels. The effect is that changing the window size
-    won't change the OSD font size.
+    Whether to scale the OSD with the window height when it is taller than 720
+    pixels (default: yes). If this is disabled, ``--osd-font-size`` and other
+    OSD options that use scaled pixels are always in actual pixels. The effect
+    is that changing the window size won't change the OSD font size.
 
     .. note::
 

DOCS/man/osc.rst

@@ -250,7 +250,7 @@ Configurable Options
 ``vidscale``
     Default: auto
 
-    Scale the OSC with the video.
+    Scale the OSC with the window height when it is taller than 720 pixels.
     ``no`` tries to keep the OSC size constant as much as the window size allows.
     ``auto`` scales the OSC with the OSD, which is scaled with the window or kept at a
     constant size, depending on the ``--osd-scale-by-window`` option.

DOCS/man/stats.rst

@@ -214,7 +214,8 @@ Configurable Options
 ``vidscale``
     Default: auto
 
-    Scale the text and graphs with the video.
+    Scale the text and graphs with the window height when it is taller than 720
+    pixels.
     ``no`` tries to keep the sizes constant.
     ``auto`` scales the text and graphs with the OSD, which is scaled with the
     window or kept at a constant size, depending on the ``--osd-scale-by-window`` option.

player/lua/osc.lua

@@ -1873,7 +1873,9 @@ local function osc_init()
     end
 
     local scale_with_video
-    if user_opts.vidscale == "auto" then
+    if display_h <= 720 then
+        scale_with_video = false
+    elseif user_opts.vidscale == "auto" then
         scale_with_video = mp.get_property_native("osd-scale-by-window")
     else
         scale_with_video = user_opts.vidscale == "yes"

player/lua/stats.lua

@@ -1527,7 +1527,9 @@ end
 
 local function update_scale(osd_height)
     local scale_with_video
-    if o.vidscale == "auto" then
+    if osd_height <= 720 then
+        scale_with_video = false
+    elseif o.vidscale == "auto" then
         scale_with_video = mp.get_property_native("osd-scale-by-window")
     else
         scale_with_video = o.vidscale == "yes"

sub/osd_libass.c

@@ -256,7 +256,7 @@ static ASS_Style *prepare_osd_ass(struct osd_state *osd, struct osd_object *obj)
 
     double playresy = obj->ass.track->PlayResY;
     // Compensate for libass and mp_ass_set_style scaling the font etc.
-    if (!opts->osd_scale_by_window)
+    if (!opts->osd_scale_by_window || obj->vo_res.h < 720)
         playresy *= 720.0 / obj->vo_res.h;
 
     ASS_Style *style = get_style(&obj->ass, "OSD");

sub/sd_ass.c

@@ -508,7 +508,7 @@ static void configure_ass(struct sd *sd, struct mp_osd_res *dim,
     if (converted || shared_opts->ass_style_override[sd->order] == ASS_STYLE_OVERRIDE_FORCE) {
         set_scale_with_window = opts->sub_scale_with_window;
         set_use_margins = opts->sub_use_margins;
-        set_scale_by_window = opts->sub_scale_by_window;
+        set_scale_by_window = opts->sub_scale_by_window && dim->h > 720;
         total_override = true;
     } else {
         set_scale_with_window = opts->ass_scale_with_window;