--Open Item(Var Actions depending of item source)--
--Open the Action list, right-click on the Action and Copy Sel Action ID--
--Insert the ID in the second column--
--For text ID used quotes--
--For no-action used zero--
---------------------------------
--SourceType    =     Action ID-- 
---------------------------------
  --Midi Files--
  MIDI          =    40153
  --Audio Files--
  WAVE          =    40638
  REX           =    40638
  FLAC          =    40638
  MP3           =    40638
  VORBIS        =    40638
  OPUS          =    40638
  --Video Files--
  VIDEO         =    50125
  --Special Files--
  RPP_PROJECT   =    41816
  EMPTY         =    40850
  CLICK         =    40011
  LTC           =    40011

--if no sel item or no-action(=0)--
  NoSelItem     =    40113
--------------------------
---------------------------------------------------------------------
function Get_Source_Type(Item_ID)
 if Item_ID then
    Take_ID=reaper.GetActiveTake(Item_ID)--Get Active Take(from Item)
    if Take_ID~=nil then
       PCM_source = reaper.GetMediaItemTake_Source(Take_ID)
       S_Type = reaper.GetMediaSourceType(PCM_source,"")
       if S_Type == "SECTION" then
          PCM_source = reaper.GetMediaSourceParent(PCM_source)
          S_Type = reaper.GetMediaSourceType(PCM_source,"")
       end
    else S_Type = "EMPTY" 
    end
 end    
return S_Type
end

function Set_ID(S_Type)
 --Midi Files-- 
 if     S_Type == "MIDI"          then ID = MIDI
 --Audio Files-- 
 elseif S_Type == "WAVE"          then ID = WAVE
 elseif S_Type == "REX"           then ID = REX
 elseif S_Type == "FLAC"          then ID = FLAC
 elseif S_Type == "MP3"           then ID = MP3
 elseif S_Type == "VORBIS"        then ID = VORBIS
 elseif S_Type == "OPUS"          then ID = OPUS
 --Video Files-- 
 elseif S_Type == "VIDEO"         then ID = VIDEO
 --Special Files--
 elseif S_Type == "RPP_PROJECT"   then ID = RPP_PROJECT
 elseif S_Type == "EMPTY"         then ID = EMPTY
 elseif S_Type == "CLICK"         then ID = CLICK
 elseif S_Type == "LTC"           then ID = LTC
 end

 --if non-native Action ID--
 if ID and type(ID)=="string" then 
    ID = reaper.NamedCommandLookup(ID)
 end
 --if Action no assigned--
 if S_Type==nil or ID==nil or ID==0 then 
    ID = NoSelItem --Action for others
 end 

return ID
end

function Run_Action()
reaper.Undo_BeginBlock()
reaper.Main_OnCommandEx(ID,0, 0)
reaper.Undo_EndBlock("Run_Action", -1)
end

----------------------------------------
Item_ID=reaper.GetSelectedMediaItem(0, 0)
Get_Source_Type(Item_ID)
Set_ID(S_Type)
reaper.defer(Run_Action)