stats: add support for deprecated properties

Previously, we used a property and when it was unavailable we assumed it
doesn't exist before assuming it really is just unavailable. This lead
to unnecessarily falling back to deprecated properties which made mpv
print deprecation warnings.
Now we can really check if a property is not known to mpv.
The alternative would've been to check the error part of mp.get_property
and perform string comparisons on the returned error message.

Not sure if supporting old mpv versions is actually worth it though.

Fixes #37 #36

player/lua/stats.lua

@@ -89,6 +89,23 @@ local function init_buffers()
     vsjitter_buf = {0, pos = 1, len = 50, max = 0}
 end
 
+-- Save all properties known to this version of mpv
+local property_list = {}
+for p in string.gmatch(mp.get_property("property-list"), "([^,]+)") do property_list[p] = true end
+-- Mapping of properties to their deprecated names
+local property_aliases = {
+    ["decoder-frame-drop-count"] = "drop-frame-count",
+    ["frame-drop-count"] = "vo-drop-frame-count",
+    ["container-fps"] = "fps",
+}
+-- Return deprecated name for the given property
+local function compat(p)
+    while not property_list[p] and property_aliases[p] do
+        p = property_aliases[p]
+    end
+    return p
+end
+
 
 local function set_ASS(b)
     if not o.ass_formatting then
@@ -236,8 +253,7 @@ local function append_perfdata(s)
 
     local ds = mp.get_property_bool("display-sync-active", false)
     local target_fps = ds and mp.get_property_number("display-fps", 0)
-                       or mp.get_property_number("container-fps", 0)
+                       or mp.get_property_number(compat("container-fps"), 0)
-                       or mp.get_property_number("fps", 0)
     if target_fps > 0 then target_fps = 1 / target_fps * 1e6 end
 
     local last_s = vo_p["render-last"] + vo_p["present-last"] + vo_p["upload-last"]
@@ -374,13 +390,8 @@ local function add_video(s)
                         {no=true, [""]=true})
     end
     append_property(s, "avsync", {prefix="A-V:"})
-    if append_property(s, "decoder-frame-drop-count", {prefix="Dropped:"}) then
+    if append_property(s, compat("decoder-frame-drop-count"), {prefix="Dropped:"}) then
-        append_property(s, "frame-drop-count", {prefix="VO:", nl=""})
+        append_property(s, compat("frame-drop-count"), {prefix="VO:", nl=""})
-        append_property(s, "mistimed-frame-count", {prefix="Mistimed:", nl=""})
-        append_property(s, "vo-delayed-frame-count", {prefix="Delayed:", nl=""})
-    -- Deprecated FPS properties for backwards compatibility
-    elseif append_property(s, "drop-frame-count", {prefix="Dropped:"}) then
-        append_property(s, "vo-drop-frame-count", {prefix="VO:", nl=""})
         append_property(s, "mistimed-frame-count", {prefix="Mistimed:", nl=""})
         append_property(s, "vo-delayed-frame-count", {prefix="Delayed:", nl=""})
     end
@@ -391,8 +402,7 @@ local function add_video(s)
         append_property(s, "estimated-display-fps",
                         {prefix="Display FPS:", suffix=" (estimated)"})
     end
-    if append_property(s, "container-fps", {prefix="FPS:", suffix=" (specified)"}) or
+    if append_property(s, compat("container-fps"), {prefix="FPS:", suffix=" (specified)"}) then
-        append_property(s, "fps", {prefix="FPS:", suffix=" (specified)"}) then
         append_property(s, "estimated-vf-fps",
                         {suffix=" (estimated)", nl="", indent=""})
     else