Document user options and add some new features (#26)

* Document user options and add some new features

I realized I've been adding to and adjusting this script for a while now and almost lost it in a reformat. I also included some requested feature's from the issue tracker. I'll comment inline to clarify some changes.

* Update speed-transition.lua

* Update README.md

* Update speed-transition.lua

* Update speed-transition.lua

README.md

@@ -7,8 +7,6 @@ The script looks for the next subtitle and if it is ahead by 5 (default) seconds
 ### Usage
 For the script to work it is necessary to have an appropriate 'text' subtitle selected and visible.
 
-If you want to use it with local files it is necessary to either have `--cache=yes` or `--demuxer-readahead-secs=10` options enabled in your config/cli. A value of `demuxer-readahead-secs>=10` is recommended. The same applies to `--cache-secs` option if it has been set.
-
 The script works best in `video-sync=audio` mode (the default in mpv), because it will then be able to minimize frame drops on speed transition from high->normal. Stutter-free playback is the result.
 
 Sensible defaults have been set, but if you want to change the `lookahead` value take care to not set it larger than what the buffers can provide. This applies to embedded subtitles and not external.
@@ -23,6 +21,10 @@ Key Bind|Effect
 `alt + j`|Toggle sub visibility on/off (non-styled subs)
 `alt + '+'`|Increase speedup
 `alt + '-'`|Decrease speedup
+`alt + '0'`|Increase leadin (time before the next subtitle to return to normal speed)
+`alt + '9'`|Decrease leadin
+`alt + '8'`|Increase Look ahead (if the next subtitle is closer than this, don't speed up)
+`alt + '7'`|Decrease Look ahead
 
 
 ## subselect

speed-transition.lua

@@ -1,12 +1,33 @@
-lookahead = 5
+lookahead = 5         --if the next subtitle appears after this threshold then speedup
-speedup = 2.5
+speedup = 2            --the value that "speed" is set to during speedup
-leadin = 1 --range 0-2
+leadin = 1            --seconds to stop short of the next subtitle
-skipmode = false
+skipmode = false      --instead of speeding up playback seek to the next known subtitle
-directskip = false
+maxSkip = 5            --max seek distance (seconds) when skipmode is enabled
----------------
+minSkip = leadin       --this is also configurable but setting it too low can actually make your watch time longer
+skipdelay = 1          --in skip mode, this setting delays each skip by x seconds (must be >=0)
+directskip = false      --seek to next known subtitle (must be in cache) no matter how far away
+dropOnAVdesync = true
+--Because mpv syncs subtitles to audio it is possible that if audio processing lags behind--
+--video processing then normal playback may not resume in sync with the video. If "avsync" > leadin--
+--then this disables the audio so that we can ensure normal playback resumes on time.
+ignorePattern = false  --if true, subtitles are matched against "subPattern". A successful match will be treated as if there was no subtitle
+subPattern = "^[#♯♩♪♬♫🎵🎶%[%(]+.*[#♯♩♪♬♫🎵🎶%]%)]+$"
+---------------User options above this line--
 
+readahead_secs = mp.get_property_native("demuxer-readahead-secs")
 normalspeed=mp.get_property_native("speed")
 
+function shouldIgnore(subtext)
+   if ignorePattern and subtext and subtext~="" then
+      local st = subtext:match("^%s*(.-)%s*$") -- trim whitespace
+      if st:find(subPattern) then
+         return true
+      end
+   else
+      return false
+   end
+end
+
 function set_timeout()
    local time_out
    if mp.get_property_native("cache-size") ~= nil then
@@ -33,6 +54,22 @@ function check_should_speedup()
    local mark = mp.get_property_native("time-pos")
    local nextsubdelay = mp.get_property_native("sub-delay")
    local nextsub = subdelay - nextsubdelay
+   if ignorePattern and nextsub > 0 then
+      local lookNext = true
+      local ignore = shouldIgnore(mp.get_property("sub-text"))
+      while ignore and lookNext do
+         local delay1 = mp.get_property_native("sub-delay")
+         mp.command("no-osd sub-step 1")
+         local delay2 = mp.get_property_native("sub-delay")
+         ignore = shouldIgnore(mp.get_property("sub-text"))
+         if delay1 == delay2 then
+            lookNext = false
+            nextsub = 0
+         else
+            nextsub = subdelay - delay2
+         end
+      end
+   end
    mp.set_property("sub-delay", subdelay)
    mp.command("no-osd set sub-visibility yes")
    return nextsub, nextsub >= lookahead or nextsub == 0, mark
@@ -41,8 +78,7 @@ end
 function check_audio(_,ds)
    if state==0 then
       return
-   end
+   elseif ds and tonumber(ds)>leadin and mp.get_property("aid")~="no" then
-   if ds and tonumber(ds)>leadin then
       aid = mp.get_property("aid")
       mp.set_property("aid", "no")
       print("avsync greater than leadin, dropping audio")
@@ -62,35 +98,62 @@ function check_position(_, position)
 end
 
 function skipval()
-   local skipval = mp.get_property_native("demuxer-cache-duration", 5)
+   local skipval = mp.get_property_native("demuxer-cache-duration", 0)
-   skipval = clamp(skipval, 1, 5)
    if nextsub > 0 then
-      if nextsub-skipval-leadin <= 0 or directskip then
+      if directskip then
-         skipval = nextsub - leadin
+         skipval =  nextsub - leadin
+      elseif nextsub - skipval - leadin <= 0 then
+         skipval =  clamp(nextsub - leadin, 0, maxSkip)
+      else
+         skipval =  clamp(skipval, 0, maxSkip)
       end
+   elseif directskip then
+      skipval = clamp(skipval - leadin, 1, nil)
    else
-      skipval = clamp(skipval-leadin, 0, nil)
+      skipval = clamp(skipval - leadin, 1, maxSkip)
-      if skipval == 0 then
-         skipval = clamp(skipval-1, 1, nil)
-      end
    end
    return skipval
 end
 
+firstskip = true   --make the first skip in skip mode not have to wait for skipdelay
+delayEnd = true
 function speed_transition(_, sub)
+   if sub~=nil and shouldIgnore(sub) then
+      sub = ""
+   end;
    if state == 0 then
       if sub == "" then
          last_speedup_zone_begin = speedup_zone_begin
          nextsub, shouldspeedup, speedup_zone_begin = check_should_speedup()
          mark = speedup_zone_begin
-         speedup_zone_end = mark+nextsub
+         speedup_zone_end = mark + nextsub
-         if shouldspeedup then
+         if shouldspeedup or (skipmode and not firstskip) then
             local temp_disable_skipmode = false
             if last_speedup_zone_begin and mark < last_speedup_zone_begin then
                temp_disable_skipmode = true
             end
             if skipmode and not temp_disable_skipmode and mp.get_property("pause") == "no" then
-               mp.commandv("no-osd", "seek", skipval(), "relative", "exact")
+               if firstskip or skipdelay == 0 then
+                  mp.commandv("no-osd", "seek", skipval(), "relative", "exact")
+                  firstskip = false
+               elseif delayEnd then
+                  delayEnd = false
+                  mp.add_timeout(skipdelay, function()
+                     delayEnd = true
+                     if mp.get_property("pause") == "no" then
+                        nextsub, shouldskip = check_should_speedup()
+                        if shouldskip or nextsub > leadin then
+                           local tSkip = skipval()
+                           currentSub = mp.get_property("sub-text")
+                           if tSkip > minSkip and (currentSub == "" or shouldIgnore(currentSub)) then
+                              mp.commandv("no-osd", "seek", tSkip, "relative", "exact")
+                           else 
+                              firstskip = true
+                           end
+                        end
+                     end
+                  end)
+               end
             else
                normalspeed = mp.get_property("speed")
                if mp.get_property_native("video-sync") == "audio" then
@@ -99,13 +162,17 @@ function speed_transition(_, sub)
                mp.set_property("speed", speedup)
                mp.observe_property("time-pos", "native", check_position)
                state = 1
-               aid=mp.get_property("aid")
+               if dropOnAVdesync then
-               mp.observe_property("avsync", "native", check_audio)
+                  aid = mp.get_property("aid")
+                  mp.observe_property("avsync", "native", check_audio)
+               end
             end
+         else
+            firstskip = true
          end
       end
    elseif state == 1 then
-      if sub ~= "" and sub ~= nil or not mp.get_property_native("sid") then
+      if (sub ~= "" and sub ~= nil) or not mp.get_property_native("sid") then
          mp.unobserve_property(check_position)
          mp.unobserve_property(check_audio)
          restore_normalspeed()
@@ -141,8 +208,10 @@ end
 function toggle_skipmode()
    skipmode = not skipmode
    if enable then
-      toggle()
+      mp.unobserve_property(speed_transition)
-      toggle()
+      mp.unobserve_property(check_position)
+      mp.observe_property("sub-text", "native", speed_transition)
+      state = 0
    end
    if skipmode then
       mp.osd_message("skip mode")
@@ -166,20 +235,28 @@ function change_speedup(v)
 end
 
 function change_leadin(v)
-   leadin = clamp(leadin + v, 0, 2)
+   --leadin = clamp(leadin + v, 0, 2)
+   leadin = clamp(leadin + v, 0, nil)
    mp.osd_message("leadin: "..leadin)
 end
 
+function change_lookAhead(v)
+   lookahead = clamp(lookahead + v , 0, nil)
+   mp.osd_message("lookahead: "..lookahead)
+end
+
 enable = false
 state = 0
 
 function toggle()
    if not enable then
       normalspeed = mp.get_property("speed")
+      mp.set_property("demuxer-readahead-secs",lookahead+leadin)
       mp.observe_property("sub-text", "native", speed_transition)
       mp.osd_message("speed-transition enabled")
    else
       restore_normalspeed()
+      mp.set_property("demuxer-readahead-secs",readahead_secs)
       mp.unobserve_property(speed_transition)
       mp.unobserve_property(check_position)
       mp.osd_message("speed-transition disabled")
@@ -199,8 +276,10 @@ 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("ctrl+alt+j", "toggle_skipmode", toggle_skipmode)
-mp.add_key_binding("alt++", "increase_speedup", function() change_speedup(0.1) end)
+mp.add_key_binding("alt++", "increase_speedup", function() change_speedup(0.1) end, {repeatable=true})
-mp.add_key_binding("alt+-", "decrease_speedup", function() change_speedup(-0.1) end)
+mp.add_key_binding("alt+-", "decrease_speedup", function() change_speedup(-0.1) end, {repeatable=true})
 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)
+mp.add_key_binding("alt+8", "increase_lookahead", function() change_lookAhead(0.25) end)
+mp.add_key_binding("alt+7", "decrease_lookahead", function() change_lookAhead(-0.25) end)
 mp.register_event("file-loaded", reset_on_file_load)