mpv: Add automatic playlist creation from directory

Added plugin to automatically load all files in the current directory
into the playlist on startup.

Will keep files 'before' the current file also 'before' in the playlist,
vice versa for files following in the directory.

mpv/.config/mpv/scripts/autoload.lua

@@ -0,0 +1,220 @@
+-- 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 it would add an already existing
+-- playlist entry at the same position - this makes it "stable".)
+-- Add at most 5000 * 2 files when starting a file (before + after).
+
+--[[
+To configure this script use file autoload.conf in directory script-opts (the "script-opts"
+directory must be in the mpv configuration directory, typically ~/.config/mpv/).
+
+Example configuration would be:
+
+disabled=no
+images=no
+videos=yes
+audio=yes
+
+--]]
+
+MAXENTRIES = 5000
+
+local msg = require 'mp.msg'
+local options = require 'mp.options'
+local utils = require 'mp.utils'
+
+o = {
+    disabled = false,
+    images = true,
+    videos = true,
+    audio = true
+}
+options.read_options(o)
+
+function Set (t)
+    local set = {}
+    for _, v in pairs(t) do set[v] = true end
+    return set
+end
+
+function SetUnion (a,b)
+    local res = {}
+    for k in pairs(a) do res[k] = true end
+    for k in pairs(b) do res[k] = true end
+    return res
+end
+
+EXTENSIONS_VIDEO = Set {
+    'mkv', 'avi', 'mp4', 'ogv', 'webm', 'rmvb', 'flv', 'wmv', 'mpeg', 'mpg', 'm4v', '3gp'
+}
+
+EXTENSIONS_AUDIO = Set {
+    'mp3', 'wav', 'ogm', 'flac', 'm4a', 'wma', 'ogg', 'opus'
+}
+
+EXTENSIONS_IMAGES = Set {
+    'jpg', 'jpeg', 'png', 'tif', 'tiff', 'gif', 'webp', 'svg', 'bmp'
+}
+
+EXTENSIONS = Set {}
+if o.videos then EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_VIDEO) end
+if o.audio then EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_AUDIO) end
+if o.images then EXTENSIONS = SetUnion(EXTENSIONS, EXTENSIONS_IMAGES) end
+
+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)
+    end
+end
+
+function get_extension(path)
+    match = string.match(path, "%.([^%.]+)$" )
+    if match == nil then
+        return "nomatch"
+    else
+        return match
+    end
+end
+
+table.filter = function(t, iter)
+    for i = #t, 1, -1 do
+        if not iter(t[i]) then
+            table.remove(t, i)
+        end
+    end
+end
+
+-- splitbynum and alnumcomp from alphanum.lua (C) Andre Bogus
+-- Released under the MIT License
+-- http://www.davekoelle.com/files/alphanum.lua
+
+-- split a string into a table of number and string values
+function splitbynum(s)
+    local result = {}
+    for x, y in (s or ""):gmatch("(%d*)(%D*)") do
+        if x ~= "" then table.insert(result, tonumber(x)) end
+        if y ~= "" then table.insert(result, y) end
+    end
+    return result
+end
+
+function clean_key(k)
+    k = (' '..k..' '):gsub("%s+", " "):sub(2, -2):lower()
+    return splitbynum(k)
+end
+
+-- compare two strings
+function alnumcomp(x, y)
+    local xt, yt = clean_key(x), clean_key(y)
+    for i = 1, math.min(#xt, #yt) do
+        local xe, ye = xt[i], yt[i]
+        if type(xe) == "string" then ye = tostring(ye)
+        elseif type(ye) == "string" then xe = tostring(xe) end
+        if xe ~= ye then return xe < ye end
+    end
+    return #xt < #yt
+end
+
+local autoloaded = nil
+
+function find_and_add_entries()
+    local path = mp.get_property("path", "")
+    local dir, filename = utils.split_path(path)
+    msg.trace(("dir: %s, filename: %s"):format(dir, filename))
+    if o.disabled then
+        msg.verbose("stopping: autoload disabled")
+        return
+    elseif #dir == 0 then
+        msg.verbose("stopping: not a local path")
+        return
+    end
+
+    local pl_count = mp.get_property_number("playlist-count", 1)
+    -- check if this is a manually made playlist
+    if (pl_count > 1 and autoloaded == nil) or
+       (pl_count == 1 and EXTENSIONS[string.lower(get_extension(filename))] == nil) then
+        msg.verbose("stopping: manually made playlist")
+        return
+    else
+        autoloaded = true
+    end
+
+    local pl = mp.get_property_native("playlist", {})
+    local pl_current = mp.get_property_number("playlist-pos-1", 1)
+    msg.trace(("playlist-pos-1: %s, playlist: %s"):format(pl_current,
+        utils.to_string(pl)))
+
+    local files = utils.readdir(dir, "files")
+    if files == nil then
+        msg.verbose("no other files in directory")
+        return
+    end
+    table.filter(files, function (v, k)
+        if string.match(v, "^%.") then
+            return false
+        end
+        local ext = get_extension(v)
+        if ext == nil then
+            return false
+        end
+        return EXTENSIONS[string.lower(ext)]
+    end)
+    table.sort(files, alnumcomp)
+
+    if dir == "." then
+        dir = ""
+    end
+
+    -- 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
+    msg.trace("current file position in files: "..current)
+
+    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.
+                msg.trace(pl_e.filename.." == "..filepath.." ?")
+                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
+                    msg.info("Prepending " .. file)
+                    table.insert(append[-1], 1, filepath)
+                end
+            else
+                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)