-- This script automatically loads playlist entries before and after the-- the currently played file. It does so by scanning the directory a file is-- located in when starting playback. It sorts the directory entries-- alphabetically, and adds entries before and after the current file to-- the internal playlist. (It stops if the it would add an already existing-- playlist entry at the same position - this makes it "stable".)-- Add at most 5 * 2 files when starting a file (before + after).MAXENTRIES = 5 function Set (t)    local set = {}    for _, v in pairs(t) do set[v] = true end    return setend EXTENSIONS = Set {    'mkv', 'avi', 'mp4', 'ogv', 'webm', 'rmvb', 'flv', 'wmv', 'mpeg', 'mpg', 'm4v', '3gp',    'mp3', 'wav', 'ogv', 'flac', 'm4a', 'wma',} mputils = require 'mp.utils' function add_files_at(index, files)    index = index - 1    local oldcount = mp.get_property_number("playlist-count", 1)    for i = 1, #files do        mp.commandv("loadfile", files[i], "append")        mp.commandv("playlist_move", oldcount + i - 1, index + i - 1)    endend function get_extension(path)    return string.match(path, "%.([^%.]+)$" )end table.filter = function(t, iter)    for i = #t, 1, -1 do        if not iter(t[i]) then            table.remove(t, i)        end    endend function find_and_add_entries()    local path = mp.get_property("path", "")    local dir, filename = mputils.split_path(path)    if #dir == 0 then        return    end    local isplaylist = mp.get_property("playlist-count")    if #isplaylist > 1 then        return    end     local files = mputils.readdir(dir, "files")    if files == nil then        return    end    table.filter(files, function (v, k)        local ext = get_extension(v)        if ext == nil then            return false        end        return EXTENSIONS[string.lower(ext)]    end)    table.sort(files, function (a, b)        return string.lower(a) < string.lower(b)    end)     if dir == "." then        dir = ""    end     local pl = mp.get_property_native("playlist", {})    local pl_current = mp.get_property_number("playlist-pos", 0) + 1    -- Find the current pl entry (dir+"/"+filename) in the sorted dir list    local current    for i = 1, #files do        if files[i] == filename then            current = i            break        end    end    if current == nil then        return    end     local append = {[-1] = {}, [1] = {}}    for direction = -1, 1, 2 do -- 2 iterations, with direction = -1 and +1        for i = 1, MAXENTRIES do            local file = files[current + i * direction]            local pl_e = pl[pl_current + i * direction]            if file == nil or file[1] == "." then                break            end             local filepath = dir .. file            if pl_e then                -- If there's a playlist entry, and it's the same file, stop.                if pl_e.filename == filepath then                    break                end            end             if direction == -1 then                if pl_current == 1 then -- never add additional entries in the middle                    mp.msg.info("Prepending " .. file)                    table.insert(append[-1], 1, filepath)                end            else                mp.msg.info("Adding " .. file)                table.insert(append[1], filepath)            end        end    end     add_files_at(pl_current + 1, append[1])    add_files_at(pl_current, append[-1])end mp.register_event("start-file", find_and_add_entries)