all changes from https://github.com/zenyd/mpv-scripts/pull/3

speed-transition.lua

@@ -1,20 +1,9 @@
-lookahead=5  --if nextsub >= lookahead then speedup
+lookahead = 5
+speedup = 2.5
+leadin = 1
+---------------
+
 normalspeed=mp.get_property_native("speed")
-speedup=2.5
-leadin=1
--------------------
-
-state=0
-enable=false
-
-function set_timeout()
-   if mp.get_property_native("cache-size") ~= nil then
-      time_out = mp.get_property_native("cache-secs")
-   else
-      time_out = mp.get_property_native("demuxer-readahead-secs")
-   end
-   return time_out
-end
 
 function restore_normalspeed()
    mp.set_property("speed", normalspeed)
@@ -24,114 +13,60 @@ function restore_normalspeed()
 end
 
 function check_should_speedup()
-   subdelay = mp.get_property_native("sub-delay")
+   local subdelay = mp.get_property_native("sub-delay")
    mp.command("no-osd set sub-visibility no")
    mp.command("no-osd sub-step 1")
-   nextsubdelay = mp.get_property_native("sub-delay")
-   nextsub = subdelay - nextsubdelay
-   --print("nextsub in seconds "..nextsub)
+   local nextsubdelay = mp.get_property_native("sub-delay")
+   local nextsub = subdelay - nextsubdelay
    mp.set_property("sub-delay", subdelay)
    mp.command("no-osd set sub-visibility yes")
    return nextsub, nextsub >= lookahead or nextsub == 0
 end
 
-function search_next_sub()
-   nextsub, _ = check_should_speedup()
-   add_timers(nextsub)
+function check_position()
+  local nextsub = check_should_speedup()
+  if nextsub ~= 0 and nextsub<=leadin then
+	 restore_normalspeed()
+	 mp.unobserve_property(check_position)
+  end
 end
 
-function add_timers(nextsub)
-   --We know when the next sub comes
-   if nextsub ~= 0 then
-      --make sure we reset the speed on the unlikely case when a timer fires
-      --within one second of the next sub
-      if nextsub - leadin > 0 then
-         mp.add_timeout((nextsub-leadin)/speedup, reset_early)
-      else
-         restore_normalspeed()
-      end
-      --We don't know when the next sub comes, so search for it recursively
-   elseif nextsub == 0 then
-      --search for next sub after time_out seconds, when its position might be known
-      if not mp.get_property_native("pause") and set_timeout() - leadin > 0 then
-         mp.add_timeout((time_out-leadin)/speedup, search_next_sub)
-      end
-   end
-end
-
---reset to normal speed before subtitle shows up
---prevents ugly audio glitches when speech starts
-function reset_early()
-   --check if it really is time to reset
-   --prevents premature change to normal speed due to seeking/pausing
-   --seeking/pausing results in firing timers early/late
-   if mp.get_property_native("sub-text") == "" and state == 1 then
-      nextsub , shouldspeedup = check_should_speedup()
-      if not shouldspeedup then
-         --print("reset_early executed")
-         restore_normalspeed()
-      else
-         --print("reset_early aborted! Seeking/Pausing?")
-      end
-   end
-end
-
-function speed_transition(subtext, sub)
+function speed_transition(_, sub)
    if state == 0 then
       if sub == "" then
-         nextsub, shouldspeedup = check_should_speedup()
+         _ , shouldspeedup = check_should_speedup()
          if shouldspeedup then
+            normalspeed = mp.get_property("speed")
             if mp.get_property_native("video-sync") == "audio" then
                mp.set_property("video-sync", "desync")
             end
-            normalspeed = mp.get_property_native("speed")
             mp.set_property("speed", speedup)
-            add_timers(nextsub)
+            mp.observe_property("time-pos", nil, check_position)
             state = 1
          end
       end
    elseif state == 1 then
       if sub ~= "" then
+         mp.unobserve_property(check_position)
          restore_normalspeed()
          state = 0
       end
    end
 end
 
-function toggle()
-   if not enable then
-      mp.observe_property("sub-text", "native", speed_transition)
-      mp.osd_message("speed-transition enabled")
-   else
-      restore_normalspeed()
-      mp.unobserve_property(speed_transition)
-      mp.osd_message("speed-transition disabled")
-   end
-   state = 0
-   enable = not enable
-end
-
-function pause(e,v)
-   if not v and state == 1 then
-      search_next_sub()
-   end
-end
-
-
-local sub_color
-local sub_color2
 toggle2 = false
 
 function toggle_sub_visibility()
    if not toggle2 then
-      sub_color = mp.get_property("sub-color", "1/1/1")
-      sub_color2 = mp.get_property("sub-border-color", "0/0/0")
+      sub_color = mp.get_property("sub-color", "1/1/1/1")
+      sub_color2 = mp.get_property("sub-border-color", "0/0/0/1")
       mp.set_property("sub-color", "0/0/0/0")
       mp.set_property("sub-border-color", "0/0/0/0")
    else
       mp.set_property("sub-color", sub_color)
       mp.set_property("sub-border-color", sub_color2)
    end
+   mp.osd_message("subtitle visibility: "..tostring(toggle2))
    toggle2 = not toggle2
 end
 
@@ -140,8 +75,32 @@ function change_speedup(v)
    mp.osd_message("speedup: "..speedup)
 end
 
-mp.observe_property("pause", "native", pause)
+function change_leadin(v)
+   leadin = leadin + v
+   mp.osd_message("leadin: "..leadin)
+end
+
+enable = false
+state = 0
+
+function toggle()
+   if not enable then
+      normalspeed = mp.get_property("speed")
+      mp.observe_property("sub-text", "native", speed_transition)
+      mp.osd_message("speed-transition enabled")
+   else
+      restore_normalspeed()
+      mp.unobserve_property(speed_transition)
+      mp.unobserve_property(check_position)
+      mp.osd_message("speed-transition disabled")
+   end
+   state = 0
+   enable = not enable
+end
+
 mp.add_key_binding("ctrl+j", "toggle_speedtrans", toggle)
 mp.add_key_binding("alt+j", "toggle_sub_visibility", toggle_sub_visibility)
 mp.add_key_binding("alt++", "increase_speedup", function() change_speedup(0.1) end)
 mp.add_key_binding("alt+-", "decrease_speedup", function() change_speedup(-0.1) end)
+mp.add_key_binding("alt+0", "increase_leadin", function() change_leadin(0.25) end)
+mp.add_key_binding("alt+9", "decrease_leadin", function() change_leadin(-0.25) end)