mpv: added hoverable previews

.config/mpv/mpv.conf

@@ -1 +1,4 @@
 fs=yes
+# for using thumbnail previews the following setting is needed
+# reference: https://github.com/TheAMM/mpv_thumbnail_script
+osc=no

.config/mpv/script-opts/mpv_thumbnail_script.conf

@@ -0,0 +1,3 @@
+autogenerate=yes
+autogenerate_max_duration=14400
+mpv_no_sub=yes

.config/mpv/scripts/mpv_thumbnail_script_server-1.lua

@@ -0,0 +1,736 @@
+--[[
+    Copyright (C) 2017 AMM
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+]]--
+--[[
+    mpv_thumbnail_script.lua 0.4.2 - commit 682becf (branch master)
+    https://github.com/TheAMM/mpv_thumbnail_script
+    Built on 2024-04-06 15:30:02
+]]--
+local assdraw = require 'mp.assdraw'
+local msg = require 'mp.msg'
+local opt = require 'mp.options'
+local utils = require 'mp.utils'
+
+-- Determine platform --
+ON_WINDOWS = (package.config:sub(1,1) ~= '/')
+
+-- Some helper functions needed to parse the options --
+function isempty(v) return (v == false) or (v == nil) or (v == "") or (v == 0) or (type(v) == "table" and next(v) == nil) end
+
+function divmod (a, b)
+  return math.floor(a / b), a % b
+end
+
+-- Better modulo
+function bmod( i, N )
+  return (i % N + N) % N
+end
+
+function join_paths(...)
+  local sep = ON_WINDOWS and "\\" or "/"
+  local result = "";
+  for i, p in pairs({...}) do
+    if p ~= "" then
+      if is_absolute_path(p) then
+        result = p
+      else
+        result = (result ~= "") and (result:gsub("[\\"..sep.."]*$", "") .. sep .. p) or p
+      end
+    end
+  end
+  return result:gsub("[\\"..sep.."]*$", "")
+end
+
+-- /some/path/file.ext -> /some/path, file.ext
+function split_path( path )
+  local sep = ON_WINDOWS and "\\" or "/"
+  local first_index, last_index = path:find('^.*' .. sep)
+
+  if last_index == nil then
+    return "", path
+  else
+    local dir = path:sub(0, last_index-1)
+    local file = path:sub(last_index+1, -1)
+
+    return dir, file
+  end
+end
+
+function is_absolute_path( path )
+  local tmp, is_win  = path:gsub("^[A-Z]:\\", "")
+  local tmp, is_unix = path:gsub("^/", "")
+  return (is_win > 0) or (is_unix > 0)
+end
+
+function Set(source)
+  local set = {}
+  for _, l in ipairs(source) do set[l] = true end
+  return set
+end
+
+---------------------------
+-- More helper functions --
+---------------------------
+
+-- Removes all keys from a table, without destroying the reference to it
+function clear_table(target)
+  for key, value in pairs(target) do
+    target[key] = nil
+  end
+end
+function shallow_copy(target)
+  local copy = {}
+  for k, v in pairs(target) do
+    copy[k] = v
+  end
+  return copy
+end
+
+-- Rounds to given decimals. eg. round_dec(3.145, 0) => 3
+function round_dec(num, idp)
+  local mult = 10^(idp or 0)
+  return math.floor(num * mult + 0.5) / mult
+end
+
+function file_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    local ok, err, code = f:read(1)
+    io.close(f)
+    return code == nil
+  else
+    return false
+  end
+end
+
+function path_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    io.close(f)
+    return true
+  else
+    return false
+  end
+end
+
+function create_directories(path)
+  local cmd
+  if ON_WINDOWS then
+    cmd = { args = {"cmd", "/c", "mkdir", path} }
+  else
+    cmd = { args = {"mkdir", "-p", path} }
+  end
+  utils.subprocess(cmd)
+end
+
+-- Find an executable in PATH or CWD with the given name
+function find_executable(name)
+  local delim = ON_WINDOWS and ";" or ":"
+
+  local pwd = os.getenv("PWD") or utils.getcwd()
+  local path = os.getenv("PATH")
+
+  local env_path = pwd .. delim .. path -- Check CWD first
+
+  local result, filename
+  for path_dir in env_path:gmatch("[^"..delim.."]+") do
+    filename = join_paths(path_dir, name)
+    if file_exists(filename) then
+      result = filename
+      break
+    end
+  end
+
+  return result
+end
+
+local ExecutableFinder = { path_cache = {} }
+-- Searches for an executable and caches the result if any
+function ExecutableFinder:get_executable_path( name, raw_name )
+  name = ON_WINDOWS and not raw_name and (name .. ".exe") or name
+
+  if self.path_cache[name] == nil then
+    self.path_cache[name] = find_executable(name) or false
+  end
+  return self.path_cache[name]
+end
+
+-- Format seconds to HH.MM.SS.sss
+function format_time(seconds, sep, decimals)
+  decimals = decimals == nil and 3 or decimals
+  sep = sep and sep or "."
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  local second_format = string.format("%%0%d.%df", 2+(decimals > 0 and decimals+1 or 0), decimals)
+
+  return string.format("%02d"..sep.."%02d"..sep..second_format, h, m, s)
+end
+
+-- Format seconds to 1h 2m 3.4s
+function format_time_hms(seconds, sep, decimals, force_full)
+  decimals = decimals == nil and 1 or decimals
+  sep = sep ~= nil and sep or " "
+
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  if force_full or h > 0 then
+    return string.format("%dh"..sep.."%dm"..sep.."%." .. tostring(decimals) .. "fs", h, m, s)
+  elseif m > 0 then
+    return string.format("%dm"..sep.."%." .. tostring(decimals) .. "fs", m, s)
+  else
+    return string.format("%." .. tostring(decimals) .. "fs", s)
+  end
+end
+
+-- Writes text on OSD and console
+function log_info(txt, timeout)
+  timeout = timeout or 1.5
+  msg.info(txt)
+  mp.osd_message(txt, timeout)
+end
+
+-- Join table items, ala ({"a", "b", "c"}, "=", "-", ", ") => "=a-, =b-, =c-"
+function join_table(source, before, after, sep)
+  before = before or ""
+  after = after or ""
+  sep = sep or ", "
+  local result = ""
+  for i, v in pairs(source) do
+    if not isempty(v) then
+      local part = before .. v .. after
+      if i == 1 then
+        result = part
+      else
+        result = result .. sep .. part
+      end
+    end
+  end
+  return result
+end
+
+function wrap(s, char)
+  char = char or "'"
+  return char .. s .. char
+end
+-- Wraps given string into 'string' and escapes any 's in it
+function escape_and_wrap(s, char, replacement)
+  char = char or "'"
+  replacement = replacement or "\\" .. char
+  return wrap(string.gsub(s, char, replacement), char)
+end
+-- Escapes single quotes in a string and wraps the input in single quotes
+function escape_single_bash(s)
+  return escape_and_wrap(s, "'", "'\\''")
+end
+
+-- Returns (a .. b) if b is not empty or nil
+function joined_or_nil(a, b)
+  return not isempty(b) and (a .. b) or nil
+end
+
+-- Put items from one table into another
+function extend_table(target, source)
+  for i, v in pairs(source) do
+    table.insert(target, v)
+  end
+end
+
+-- Creates a handle and filename for a temporary random file (in current directory)
+function create_temporary_file(base, mode, suffix)
+  local handle, filename
+  suffix = suffix or ""
+  while true do
+    filename = base .. tostring(math.random(1, 5000)) .. suffix
+    handle = io.open(filename, "r")
+    if not handle then
+      handle = io.open(filename, mode)
+      break
+    end
+    io.close(handle)
+  end
+  return handle, filename
+end
+
+
+function get_processor_count()
+  local proc_count
+
+  if ON_WINDOWS then
+    proc_count = tonumber(os.getenv("NUMBER_OF_PROCESSORS"))
+  else
+    local cpuinfo_handle = io.open("/proc/cpuinfo")
+    if cpuinfo_handle ~= nil then
+      local cpuinfo_contents = cpuinfo_handle:read("*a")
+      local _, replace_count = cpuinfo_contents:gsub('processor', '')
+      proc_count = replace_count
+    end
+  end
+
+  if proc_count and proc_count > 0 then
+      return proc_count
+  else
+    return nil
+  end
+end
+
+function substitute_values(string, values)
+  local substitutor = function(match)
+    if match == "%" then
+       return "%"
+    else
+      -- nil is discarded by gsub
+      return values[match]
+    end
+  end
+
+  local substituted = string:gsub('%%(.)', substitutor)
+  return substituted
+end
+
+-- ASS HELPERS --
+function round_rect_top( ass, x0, y0, x1, y1, r )
+  local c = 0.551915024494 * r -- circle approximation
+  ass:move_to(x0 + r, y0)
+  ass:line_to(x1 - r, y0) -- top line
+  if r > 0 then
+      ass:bezier_curve(x1 - r + c, y0, x1, y0 + r - c, x1, y0 + r) -- top right corner
+  end
+  ass:line_to(x1, y1) -- right line
+  ass:line_to(x0, y1) -- bottom line
+  ass:line_to(x0, y0 + r) -- left line
+  if r > 0 then
+      ass:bezier_curve(x0, y0 + r - c, x0 + r - c, y0, x0 + r, y0) -- top left corner
+  end
+end
+
+function round_rect(ass, x0, y0, x1, y1, rtl, rtr, rbr, rbl)
+    local c = 0.551915024494
+    ass:move_to(x0 + rtl, y0)
+    ass:line_to(x1 - rtr, y0) -- top line
+    if rtr > 0 then
+        ass:bezier_curve(x1 - rtr + rtr*c, y0, x1, y0 + rtr - rtr*c, x1, y0 + rtr) -- top right corner
+    end
+    ass:line_to(x1, y1 - rbr) -- right line
+    if rbr > 0 then
+        ass:bezier_curve(x1, y1 - rbr + rbr*c, x1 - rbr + rbr*c, y1, x1 - rbr, y1) -- bottom right corner
+    end
+    ass:line_to(x0 + rbl, y1) -- bottom line
+    if rbl > 0 then
+        ass:bezier_curve(x0 + rbl - rbl*c, y1, x0, y1 - rbl + rbl*c, x0, y1 - rbl) -- bottom left corner
+    end
+    ass:line_to(x0, y0 + rtl) -- left line
+    if rtl > 0 then
+        ass:bezier_curve(x0, y0 + rtl - rtl*c, x0 + rtl - rtl*c, y0, x0 + rtl, y0) -- top left corner
+    end
+end
+local SCRIPT_NAME = "mpv_thumbnail_script"
+
+local default_cache_base = ON_WINDOWS and os.getenv("TEMP") or "/tmp/"
+
+local thumbnailer_options = {
+    -- The thumbnail directory
+    cache_directory = join_paths(default_cache_base, "mpv_thumbs_cache"),
+
+    ------------------------
+    -- Generation options --
+    ------------------------
+
+    -- Automatically generate the thumbnails on video load, without a keypress
+    autogenerate = true,
+
+    -- Only automatically thumbnail videos shorter than this (seconds)
+    autogenerate_max_duration = 3600, -- 1 hour
+
+    -- SHA1-sum filenames over this length
+    -- It's nice to know what files the thumbnails are (hence directory names)
+    -- but long URLs may approach filesystem limits.
+    hash_filename_length = 128,
+
+    -- Use mpv to generate thumbnail even if ffmpeg is found in PATH
+    -- ffmpeg does not handle ordered chapters (MKVs which rely on other MKVs)!
+    -- mpv is a bit slower, but has better support overall (eg. subtitles in the previews)
+    prefer_mpv = true,
+
+    -- Explicitly disable subtitles on the mpv sub-calls
+    mpv_no_sub = false,
+    -- Add a "--no-config" to the mpv sub-call arguments
+    mpv_no_config = false,
+    -- Add a "--profile=<mpv_profile>" to the mpv sub-call arguments
+    -- Use "" to disable
+    mpv_profile = "",
+    -- Output debug logs to <thumbnail_path>.log, ala <cache_directory>/<video_filename>/000000.bgra.log
+    -- The logs are removed after successful encodes, unless you set mpv_keep_logs below
+    mpv_logs = true,
+    -- Keep all mpv logs, even the succesfull ones
+    mpv_keep_logs = false,
+
+    -- Disable the built-in keybind ("T") to add your own
+    disable_keybinds = false,
+
+    ---------------------
+    -- Display options --
+    ---------------------
+
+    -- Move the thumbnail up or down
+    -- For example:
+    --   topbar/bottombar: 24
+    --   rest: 0
+    vertical_offset = 24,
+
+    -- Adjust background padding
+    -- Examples:
+    --   topbar:       0, 10, 10, 10
+    --   bottombar:   10,  0, 10, 10
+    --   slimbox/box: 10, 10, 10, 10
+    pad_top   = 10,
+    pad_bot   =  0,
+    pad_left  = 10,
+    pad_right = 10,
+
+    -- If true, pad values are screen-pixels. If false, video-pixels.
+    pad_in_screenspace = true,
+    -- Calculate pad into the offset
+    offset_by_pad = true,
+
+    -- Background color in BBGGRR
+    background_color = "000000",
+    -- Alpha: 0 - fully opaque, 255 - transparent
+    background_alpha = 80,
+
+    -- Keep thumbnail on the screen near left or right side
+    constrain_to_screen = true,
+
+    -- Do not display the thumbnailing progress
+    hide_progress = false,
+
+    -----------------------
+    -- Thumbnail options --
+    -----------------------
+
+    -- The maximum dimensions of the thumbnails (pixels)
+    thumbnail_width = 200,
+    thumbnail_height = 200,
+
+    -- The thumbnail count target
+    -- (This will result in a thumbnail every ~10 seconds for a 25 minute video)
+    thumbnail_count = 150,
+
+    -- The above target count will be adjusted by the minimum and
+    -- maximum time difference between thumbnails.
+    -- The thumbnail_count will be used to calculate a target separation,
+    -- and min/max_delta will be used to constrict it.
+
+    -- In other words, thumbnails will be:
+    --   at least min_delta seconds apart (limiting the amount)
+    --   at most max_delta seconds apart (raising the amount if needed)
+    min_delta = 5,
+    -- 120 seconds aka 2 minutes will add more thumbnails when the video is over 5 hours!
+    max_delta = 90,
+
+
+    -- Overrides for remote urls (you generally want less thumbnails!)
+    -- Thumbnailing network paths will be done with mpv
+
+    -- Allow thumbnailing network paths (naive check for "://")
+    thumbnail_network = false,
+    -- Override thumbnail count, min/max delta
+    remote_thumbnail_count = 60,
+    remote_min_delta = 15,
+    remote_max_delta = 120,
+
+    -- Try to grab the raw stream and disable ytdl for the mpv subcalls
+    -- Much faster than passing the url to ytdl again, but may cause problems with some sites
+    remote_direct_stream = true,
+}
+
+read_options(thumbnailer_options, SCRIPT_NAME)
+function skip_nil(tbl)
+    local n = {}
+    for k, v in pairs(tbl) do
+        table.insert(n, v)
+    end
+    return n
+end
+
+function create_thumbnail_mpv(file_path, timestamp, size, output_path, options)
+    options = options or {}
+
+    local ytdl_disabled = not options.enable_ytdl and (mp.get_property_native("ytdl") == false
+                                                       or thumbnailer_options.remote_direct_stream)
+
+    local header_fields_arg = nil
+    local header_fields = mp.get_property_native("http-header-fields")
+    if #header_fields > 0 then
+        -- We can't escape the headers, mpv won't parse "--http-header-fields='Name: value'" properly
+        header_fields_arg = "--http-header-fields=" .. table.concat(header_fields, ",")
+    end
+
+    local profile_arg = nil
+    if thumbnailer_options.mpv_profile ~= "" then
+        profile_arg = "--profile=" .. thumbnailer_options.mpv_profile
+    end
+
+    local log_arg = "--log-file=" .. output_path .. ".log"
+
+    local mpv_command = skip_nil({
+        "mpv",
+        -- Hide console output
+        "--msg-level=all=no",
+
+        -- Disable ytdl
+        (ytdl_disabled and "--no-ytdl" or nil),
+        -- Pass HTTP headers from current instance
+        header_fields_arg,
+        -- Pass User-Agent and Referer - should do no harm even with ytdl active
+        "--user-agent=" .. mp.get_property_native("user-agent"),
+        "--referrer=" .. mp.get_property_native("referrer"),
+        -- Disable hardware decoding
+        "--hwdec=no",
+
+        -- Insert --no-config, --profile=... and --log-file if enabled
+        (thumbnailer_options.mpv_no_config and "--no-config" or nil),
+        profile_arg,
+        (thumbnailer_options.mpv_logs and log_arg or nil),
+
+        file_path,
+
+        "--start=" .. tostring(timestamp),
+        "--frames=1",
+        "--hr-seek=yes",
+        "--no-audio",
+        -- Optionally disable subtitles
+        (thumbnailer_options.mpv_no_sub and "--no-sub" or nil),
+
+        ("--vf=scale=%d:%d"):format(size.w, size.h),
+        "--vf-add=format=bgra",
+        "--of=rawvideo",
+        "--ovc=rawvideo",
+        "--o=" .. output_path
+    })
+    return utils.subprocess({args=mpv_command})
+end
+
+
+function create_thumbnail_ffmpeg(file_path, timestamp, size, output_path)
+    local ffmpeg_command = {
+        "ffmpeg",
+        "-loglevel", "quiet",
+        "-noaccurate_seek",
+        "-ss", format_time(timestamp, ":"),
+        "-i", file_path,
+
+        "-frames:v", "1",
+        "-an",
+
+        "-vf", ("scale=%d:%d"):format(size.w, size.h),
+        "-c:v", "rawvideo",
+        "-pix_fmt", "bgra",
+        "-f", "rawvideo",
+
+        "-y", output_path
+    }
+    return utils.subprocess({args=ffmpeg_command})
+end
+
+
+function check_output(ret, output_path, is_mpv)
+    local log_path = output_path .. ".log"
+    local success = true
+
+    if ret.killed_by_us then
+        return nil
+    else
+        if ret.error or ret.status ~= 0 then
+            msg.error("Thumbnailing command failed!")
+            msg.error("mpv process error:", ret.error)
+            msg.error("Process stdout:", ret.stdout)
+            if is_mpv then
+                msg.error("Debug log:", log_path)
+            end
+
+            success = false
+        end
+
+        if not file_exists(output_path) then
+            msg.error("Output file missing!", output_path)
+            success = false
+        end
+    end
+
+    if is_mpv and not thumbnailer_options.mpv_keep_logs then
+        -- Remove successful debug logs
+        if success and file_exists(log_path) then
+            os.remove(log_path)
+        end
+    end
+
+    return success
+end
+
+
+function do_worker_job(state_json_string, frames_json_string)
+    msg.debug("Handling given job")
+    local thumb_state, err = utils.parse_json(state_json_string)
+    if err then
+        msg.error("Failed to parse state JSON")
+        return
+    end
+
+    local thumbnail_indexes, err = utils.parse_json(frames_json_string)
+    if err then
+        msg.error("Failed to parse thumbnail frame indexes")
+        return
+    end
+
+    local thumbnail_func = create_thumbnail_mpv
+    if not thumbnailer_options.prefer_mpv then
+        if ExecutableFinder:get_executable_path("ffmpeg") then
+            thumbnail_func = create_thumbnail_ffmpeg
+        else
+            msg.warn("Could not find ffmpeg in PATH! Falling back on mpv.")
+        end
+    end
+
+    local file_duration = mp.get_property_native("duration")
+    local file_path = thumb_state.worker_input_path
+
+    if thumb_state.is_remote then
+        if (thumbnail_func == create_thumbnail_ffmpeg) then
+            msg.warn("Thumbnailing remote path, falling back on mpv.")
+        end
+        thumbnail_func = create_thumbnail_mpv
+    end
+
+    local generate_thumbnail_for_index = function(thumbnail_index)
+        -- Given a 1-based thumbnail index, generate a thumbnail for it based on the thumbnailer state
+        local thumb_idx = thumbnail_index - 1
+        msg.debug("Starting work on thumbnail", thumb_idx)
+
+        local thumbnail_path = thumb_state.thumbnail_template:format(thumb_idx)
+        -- Grab the "middle" of the thumbnail duration instead of the very start, and leave some margin in the end
+        local timestamp = math.min(file_duration - 0.25, (thumb_idx + 0.5) * thumb_state.thumbnail_delta)
+
+        mp.commandv("script-message", "mpv_thumbnail_script-progress", tostring(thumbnail_index))
+
+        -- The expected size (raw BGRA image)
+        local thumbnail_raw_size = (thumb_state.thumbnail_size.w * thumb_state.thumbnail_size.h * 4)
+
+        local need_thumbnail_generation = false
+
+        -- Check if the thumbnail already exists and is the correct size
+        local thumbnail_file = io.open(thumbnail_path, "rb")
+        if thumbnail_file == nil then
+            need_thumbnail_generation = true
+        else
+            local existing_thumbnail_filesize = thumbnail_file:seek("end")
+            if existing_thumbnail_filesize ~= thumbnail_raw_size then
+                -- Size doesn't match, so (re)generate
+                msg.warn("Thumbnail", thumb_idx, "did not match expected size, regenerating")
+                need_thumbnail_generation = true
+            end
+            thumbnail_file:close()
+        end
+
+        if need_thumbnail_generation then
+            local ret = thumbnail_func(file_path, timestamp, thumb_state.thumbnail_size, thumbnail_path, thumb_state.worker_extra)
+            local success = check_output(ret, thumbnail_path, thumbnail_func == create_thumbnail_mpv)
+
+            if success == nil then
+                -- Killed by us, changing files, ignore
+                msg.debug("Changing files, subprocess killed")
+                return true
+            elseif not success then
+                -- Real failure
+                mp.osd_message("Thumbnailing failed, check console for details", 3.5)
+                return true
+            end
+        else
+            msg.debug("Thumbnail", thumb_idx, "already done!")
+        end
+
+        -- Verify thumbnail size
+        -- Sometimes ffmpeg will output an empty file when seeking to a "bad" section (usually the end)
+        thumbnail_file = io.open(thumbnail_path, "rb")
+
+        -- Bail if we can't read the file (it should really exist by now, we checked this in check_output!)
+        if thumbnail_file == nil then
+            msg.error("Thumbnail suddenly disappeared!")
+            return true
+        end
+
+        -- Check the size of the generated file
+        local thumbnail_file_size = thumbnail_file:seek("end")
+        thumbnail_file:close()
+
+        -- Check if the file is big enough
+        local missing_bytes = math.max(0, thumbnail_raw_size - thumbnail_file_size)
+        if missing_bytes > 0 then
+            msg.warn(("Thumbnail missing %d bytes (expected %d, had %d), padding %s"):format(
+              missing_bytes, thumbnail_raw_size, thumbnail_file_size, thumbnail_path
+            ))
+            -- Pad the file if it's missing content (eg. ffmpeg seek to file end)
+            thumbnail_file = io.open(thumbnail_path, "ab")
+            thumbnail_file:write(string.rep(string.char(0), missing_bytes))
+            thumbnail_file:close()
+        end
+
+        msg.debug("Finished work on thumbnail", thumb_idx)
+        mp.commandv("script-message", "mpv_thumbnail_script-ready", tostring(thumbnail_index), thumbnail_path)
+    end
+
+    msg.debug(("Generating %d thumbnails @ %dx%d for %q"):format(
+        #thumbnail_indexes,
+        thumb_state.thumbnail_size.w,
+        thumb_state.thumbnail_size.h,
+        file_path))
+
+    for i, thumbnail_index in ipairs(thumbnail_indexes) do
+        local bail = generate_thumbnail_for_index(thumbnail_index)
+        if bail then return end
+    end
+
+end
+
+-- Set up listeners and keybinds
+
+-- Job listener
+mp.register_script_message("mpv_thumbnail_script-job", do_worker_job)
+
+
+-- Register this worker with the master script
+local register_timer = nil
+local register_timeout = mp.get_time() + 1.5
+
+local register_function = function()
+    if mp.get_time() > register_timeout and register_timer then
+        msg.error("Thumbnail worker registering timed out")
+        register_timer:stop()
+    else
+        msg.debug("Announcing self to master...")
+        mp.commandv("script-message", "mpv_thumbnail_script-worker", mp.get_script_name())
+    end
+end
+
+register_timer = mp.add_periodic_timer(0.1, register_function)
+
+mp.register_script_message("mpv_thumbnail_script-slaved", function()
+    msg.debug("Successfully registered with master")
+    register_timer:stop()
+end)

.config/mpv/scripts/mpv_thumbnail_script_server-2.lua

@@ -0,0 +1,736 @@
+--[[
+    Copyright (C) 2017 AMM
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+]]--
+--[[
+    mpv_thumbnail_script.lua 0.4.2 - commit 682becf (branch master)
+    https://github.com/TheAMM/mpv_thumbnail_script
+    Built on 2024-04-06 15:30:02
+]]--
+local assdraw = require 'mp.assdraw'
+local msg = require 'mp.msg'
+local opt = require 'mp.options'
+local utils = require 'mp.utils'
+
+-- Determine platform --
+ON_WINDOWS = (package.config:sub(1,1) ~= '/')
+
+-- Some helper functions needed to parse the options --
+function isempty(v) return (v == false) or (v == nil) or (v == "") or (v == 0) or (type(v) == "table" and next(v) == nil) end
+
+function divmod (a, b)
+  return math.floor(a / b), a % b
+end
+
+-- Better modulo
+function bmod( i, N )
+  return (i % N + N) % N
+end
+
+function join_paths(...)
+  local sep = ON_WINDOWS and "\\" or "/"
+  local result = "";
+  for i, p in pairs({...}) do
+    if p ~= "" then
+      if is_absolute_path(p) then
+        result = p
+      else
+        result = (result ~= "") and (result:gsub("[\\"..sep.."]*$", "") .. sep .. p) or p
+      end
+    end
+  end
+  return result:gsub("[\\"..sep.."]*$", "")
+end
+
+-- /some/path/file.ext -> /some/path, file.ext
+function split_path( path )
+  local sep = ON_WINDOWS and "\\" or "/"
+  local first_index, last_index = path:find('^.*' .. sep)
+
+  if last_index == nil then
+    return "", path
+  else
+    local dir = path:sub(0, last_index-1)
+    local file = path:sub(last_index+1, -1)
+
+    return dir, file
+  end
+end
+
+function is_absolute_path( path )
+  local tmp, is_win  = path:gsub("^[A-Z]:\\", "")
+  local tmp, is_unix = path:gsub("^/", "")
+  return (is_win > 0) or (is_unix > 0)
+end
+
+function Set(source)
+  local set = {}
+  for _, l in ipairs(source) do set[l] = true end
+  return set
+end
+
+---------------------------
+-- More helper functions --
+---------------------------
+
+-- Removes all keys from a table, without destroying the reference to it
+function clear_table(target)
+  for key, value in pairs(target) do
+    target[key] = nil
+  end
+end
+function shallow_copy(target)
+  local copy = {}
+  for k, v in pairs(target) do
+    copy[k] = v
+  end
+  return copy
+end
+
+-- Rounds to given decimals. eg. round_dec(3.145, 0) => 3
+function round_dec(num, idp)
+  local mult = 10^(idp or 0)
+  return math.floor(num * mult + 0.5) / mult
+end
+
+function file_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    local ok, err, code = f:read(1)
+    io.close(f)
+    return code == nil
+  else
+    return false
+  end
+end
+
+function path_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    io.close(f)
+    return true
+  else
+    return false
+  end
+end
+
+function create_directories(path)
+  local cmd
+  if ON_WINDOWS then
+    cmd = { args = {"cmd", "/c", "mkdir", path} }
+  else
+    cmd = { args = {"mkdir", "-p", path} }
+  end
+  utils.subprocess(cmd)
+end
+
+-- Find an executable in PATH or CWD with the given name
+function find_executable(name)
+  local delim = ON_WINDOWS and ";" or ":"
+
+  local pwd = os.getenv("PWD") or utils.getcwd()
+  local path = os.getenv("PATH")
+
+  local env_path = pwd .. delim .. path -- Check CWD first
+
+  local result, filename
+  for path_dir in env_path:gmatch("[^"..delim.."]+") do
+    filename = join_paths(path_dir, name)
+    if file_exists(filename) then
+      result = filename
+      break
+    end
+  end
+
+  return result
+end
+
+local ExecutableFinder = { path_cache = {} }
+-- Searches for an executable and caches the result if any
+function ExecutableFinder:get_executable_path( name, raw_name )
+  name = ON_WINDOWS and not raw_name and (name .. ".exe") or name
+
+  if self.path_cache[name] == nil then
+    self.path_cache[name] = find_executable(name) or false
+  end
+  return self.path_cache[name]
+end
+
+-- Format seconds to HH.MM.SS.sss
+function format_time(seconds, sep, decimals)
+  decimals = decimals == nil and 3 or decimals
+  sep = sep and sep or "."
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  local second_format = string.format("%%0%d.%df", 2+(decimals > 0 and decimals+1 or 0), decimals)
+
+  return string.format("%02d"..sep.."%02d"..sep..second_format, h, m, s)
+end
+
+-- Format seconds to 1h 2m 3.4s
+function format_time_hms(seconds, sep, decimals, force_full)
+  decimals = decimals == nil and 1 or decimals
+  sep = sep ~= nil and sep or " "
+
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  if force_full or h > 0 then
+    return string.format("%dh"..sep.."%dm"..sep.."%." .. tostring(decimals) .. "fs", h, m, s)
+  elseif m > 0 then
+    return string.format("%dm"..sep.."%." .. tostring(decimals) .. "fs", m, s)
+  else
+    return string.format("%." .. tostring(decimals) .. "fs", s)
+  end
+end
+
+-- Writes text on OSD and console
+function log_info(txt, timeout)
+  timeout = timeout or 1.5
+  msg.info(txt)
+  mp.osd_message(txt, timeout)
+end
+
+-- Join table items, ala ({"a", "b", "c"}, "=", "-", ", ") => "=a-, =b-, =c-"
+function join_table(source, before, after, sep)
+  before = before or ""
+  after = after or ""
+  sep = sep or ", "
+  local result = ""
+  for i, v in pairs(source) do
+    if not isempty(v) then
+      local part = before .. v .. after
+      if i == 1 then
+        result = part
+      else
+        result = result .. sep .. part
+      end
+    end
+  end
+  return result
+end
+
+function wrap(s, char)
+  char = char or "'"
+  return char .. s .. char
+end
+-- Wraps given string into 'string' and escapes any 's in it
+function escape_and_wrap(s, char, replacement)
+  char = char or "'"
+  replacement = replacement or "\\" .. char
+  return wrap(string.gsub(s, char, replacement), char)
+end
+-- Escapes single quotes in a string and wraps the input in single quotes
+function escape_single_bash(s)
+  return escape_and_wrap(s, "'", "'\\''")
+end
+
+-- Returns (a .. b) if b is not empty or nil
+function joined_or_nil(a, b)
+  return not isempty(b) and (a .. b) or nil
+end
+
+-- Put items from one table into another
+function extend_table(target, source)
+  for i, v in pairs(source) do
+    table.insert(target, v)
+  end
+end
+
+-- Creates a handle and filename for a temporary random file (in current directory)
+function create_temporary_file(base, mode, suffix)
+  local handle, filename
+  suffix = suffix or ""
+  while true do
+    filename = base .. tostring(math.random(1, 5000)) .. suffix
+    handle = io.open(filename, "r")
+    if not handle then
+      handle = io.open(filename, mode)
+      break
+    end
+    io.close(handle)
+  end
+  return handle, filename
+end
+
+
+function get_processor_count()
+  local proc_count
+
+  if ON_WINDOWS then
+    proc_count = tonumber(os.getenv("NUMBER_OF_PROCESSORS"))
+  else
+    local cpuinfo_handle = io.open("/proc/cpuinfo")
+    if cpuinfo_handle ~= nil then
+      local cpuinfo_contents = cpuinfo_handle:read("*a")
+      local _, replace_count = cpuinfo_contents:gsub('processor', '')
+      proc_count = replace_count
+    end
+  end
+
+  if proc_count and proc_count > 0 then
+      return proc_count
+  else
+    return nil
+  end
+end
+
+function substitute_values(string, values)
+  local substitutor = function(match)
+    if match == "%" then
+       return "%"
+    else
+      -- nil is discarded by gsub
+      return values[match]
+    end
+  end
+
+  local substituted = string:gsub('%%(.)', substitutor)
+  return substituted
+end
+
+-- ASS HELPERS --
+function round_rect_top( ass, x0, y0, x1, y1, r )
+  local c = 0.551915024494 * r -- circle approximation
+  ass:move_to(x0 + r, y0)
+  ass:line_to(x1 - r, y0) -- top line
+  if r > 0 then
+      ass:bezier_curve(x1 - r + c, y0, x1, y0 + r - c, x1, y0 + r) -- top right corner
+  end
+  ass:line_to(x1, y1) -- right line
+  ass:line_to(x0, y1) -- bottom line
+  ass:line_to(x0, y0 + r) -- left line
+  if r > 0 then
+      ass:bezier_curve(x0, y0 + r - c, x0 + r - c, y0, x0 + r, y0) -- top left corner
+  end
+end
+
+function round_rect(ass, x0, y0, x1, y1, rtl, rtr, rbr, rbl)
+    local c = 0.551915024494
+    ass:move_to(x0 + rtl, y0)
+    ass:line_to(x1 - rtr, y0) -- top line
+    if rtr > 0 then
+        ass:bezier_curve(x1 - rtr + rtr*c, y0, x1, y0 + rtr - rtr*c, x1, y0 + rtr) -- top right corner
+    end
+    ass:line_to(x1, y1 - rbr) -- right line
+    if rbr > 0 then
+        ass:bezier_curve(x1, y1 - rbr + rbr*c, x1 - rbr + rbr*c, y1, x1 - rbr, y1) -- bottom right corner
+    end
+    ass:line_to(x0 + rbl, y1) -- bottom line
+    if rbl > 0 then
+        ass:bezier_curve(x0 + rbl - rbl*c, y1, x0, y1 - rbl + rbl*c, x0, y1 - rbl) -- bottom left corner
+    end
+    ass:line_to(x0, y0 + rtl) -- left line
+    if rtl > 0 then
+        ass:bezier_curve(x0, y0 + rtl - rtl*c, x0 + rtl - rtl*c, y0, x0 + rtl, y0) -- top left corner
+    end
+end
+local SCRIPT_NAME = "mpv_thumbnail_script"
+
+local default_cache_base = ON_WINDOWS and os.getenv("TEMP") or "/tmp/"
+
+local thumbnailer_options = {
+    -- The thumbnail directory
+    cache_directory = join_paths(default_cache_base, "mpv_thumbs_cache"),
+
+    ------------------------
+    -- Generation options --
+    ------------------------
+
+    -- Automatically generate the thumbnails on video load, without a keypress
+    autogenerate = true,
+
+    -- Only automatically thumbnail videos shorter than this (seconds)
+    autogenerate_max_duration = 3600, -- 1 hour
+
+    -- SHA1-sum filenames over this length
+    -- It's nice to know what files the thumbnails are (hence directory names)
+    -- but long URLs may approach filesystem limits.
+    hash_filename_length = 128,
+
+    -- Use mpv to generate thumbnail even if ffmpeg is found in PATH
+    -- ffmpeg does not handle ordered chapters (MKVs which rely on other MKVs)!
+    -- mpv is a bit slower, but has better support overall (eg. subtitles in the previews)
+    prefer_mpv = true,
+
+    -- Explicitly disable subtitles on the mpv sub-calls
+    mpv_no_sub = false,
+    -- Add a "--no-config" to the mpv sub-call arguments
+    mpv_no_config = false,
+    -- Add a "--profile=<mpv_profile>" to the mpv sub-call arguments
+    -- Use "" to disable
+    mpv_profile = "",
+    -- Output debug logs to <thumbnail_path>.log, ala <cache_directory>/<video_filename>/000000.bgra.log
+    -- The logs are removed after successful encodes, unless you set mpv_keep_logs below
+    mpv_logs = true,
+    -- Keep all mpv logs, even the succesfull ones
+    mpv_keep_logs = false,
+
+    -- Disable the built-in keybind ("T") to add your own
+    disable_keybinds = false,
+
+    ---------------------
+    -- Display options --
+    ---------------------
+
+    -- Move the thumbnail up or down
+    -- For example:
+    --   topbar/bottombar: 24
+    --   rest: 0
+    vertical_offset = 24,
+
+    -- Adjust background padding
+    -- Examples:
+    --   topbar:       0, 10, 10, 10
+    --   bottombar:   10,  0, 10, 10
+    --   slimbox/box: 10, 10, 10, 10
+    pad_top   = 10,
+    pad_bot   =  0,
+    pad_left  = 10,
+    pad_right = 10,
+
+    -- If true, pad values are screen-pixels. If false, video-pixels.
+    pad_in_screenspace = true,
+    -- Calculate pad into the offset
+    offset_by_pad = true,
+
+    -- Background color in BBGGRR
+    background_color = "000000",
+    -- Alpha: 0 - fully opaque, 255 - transparent
+    background_alpha = 80,
+
+    -- Keep thumbnail on the screen near left or right side
+    constrain_to_screen = true,
+
+    -- Do not display the thumbnailing progress
+    hide_progress = false,
+
+    -----------------------
+    -- Thumbnail options --
+    -----------------------
+
+    -- The maximum dimensions of the thumbnails (pixels)
+    thumbnail_width = 200,
+    thumbnail_height = 200,
+
+    -- The thumbnail count target
+    -- (This will result in a thumbnail every ~10 seconds for a 25 minute video)
+    thumbnail_count = 150,
+
+    -- The above target count will be adjusted by the minimum and
+    -- maximum time difference between thumbnails.
+    -- The thumbnail_count will be used to calculate a target separation,
+    -- and min/max_delta will be used to constrict it.
+
+    -- In other words, thumbnails will be:
+    --   at least min_delta seconds apart (limiting the amount)
+    --   at most max_delta seconds apart (raising the amount if needed)
+    min_delta = 5,
+    -- 120 seconds aka 2 minutes will add more thumbnails when the video is over 5 hours!
+    max_delta = 90,
+
+
+    -- Overrides for remote urls (you generally want less thumbnails!)
+    -- Thumbnailing network paths will be done with mpv
+
+    -- Allow thumbnailing network paths (naive check for "://")
+    thumbnail_network = false,
+    -- Override thumbnail count, min/max delta
+    remote_thumbnail_count = 60,
+    remote_min_delta = 15,
+    remote_max_delta = 120,
+
+    -- Try to grab the raw stream and disable ytdl for the mpv subcalls
+    -- Much faster than passing the url to ytdl again, but may cause problems with some sites
+    remote_direct_stream = true,
+}
+
+read_options(thumbnailer_options, SCRIPT_NAME)
+function skip_nil(tbl)
+    local n = {}
+    for k, v in pairs(tbl) do
+        table.insert(n, v)
+    end
+    return n
+end
+
+function create_thumbnail_mpv(file_path, timestamp, size, output_path, options)
+    options = options or {}
+
+    local ytdl_disabled = not options.enable_ytdl and (mp.get_property_native("ytdl") == false
+                                                       or thumbnailer_options.remote_direct_stream)
+
+    local header_fields_arg = nil
+    local header_fields = mp.get_property_native("http-header-fields")
+    if #header_fields > 0 then
+        -- We can't escape the headers, mpv won't parse "--http-header-fields='Name: value'" properly
+        header_fields_arg = "--http-header-fields=" .. table.concat(header_fields, ",")
+    end
+
+    local profile_arg = nil
+    if thumbnailer_options.mpv_profile ~= "" then
+        profile_arg = "--profile=" .. thumbnailer_options.mpv_profile
+    end
+
+    local log_arg = "--log-file=" .. output_path .. ".log"
+
+    local mpv_command = skip_nil({
+        "mpv",
+        -- Hide console output
+        "--msg-level=all=no",
+
+        -- Disable ytdl
+        (ytdl_disabled and "--no-ytdl" or nil),
+        -- Pass HTTP headers from current instance
+        header_fields_arg,
+        -- Pass User-Agent and Referer - should do no harm even with ytdl active
+        "--user-agent=" .. mp.get_property_native("user-agent"),
+        "--referrer=" .. mp.get_property_native("referrer"),
+        -- Disable hardware decoding
+        "--hwdec=no",
+
+        -- Insert --no-config, --profile=... and --log-file if enabled
+        (thumbnailer_options.mpv_no_config and "--no-config" or nil),
+        profile_arg,
+        (thumbnailer_options.mpv_logs and log_arg or nil),
+
+        file_path,
+
+        "--start=" .. tostring(timestamp),
+        "--frames=1",
+        "--hr-seek=yes",
+        "--no-audio",
+        -- Optionally disable subtitles
+        (thumbnailer_options.mpv_no_sub and "--no-sub" or nil),
+
+        ("--vf=scale=%d:%d"):format(size.w, size.h),
+        "--vf-add=format=bgra",
+        "--of=rawvideo",
+        "--ovc=rawvideo",
+        "--o=" .. output_path
+    })
+    return utils.subprocess({args=mpv_command})
+end
+
+
+function create_thumbnail_ffmpeg(file_path, timestamp, size, output_path)
+    local ffmpeg_command = {
+        "ffmpeg",
+        "-loglevel", "quiet",
+        "-noaccurate_seek",
+        "-ss", format_time(timestamp, ":"),
+        "-i", file_path,
+
+        "-frames:v", "1",
+        "-an",
+
+        "-vf", ("scale=%d:%d"):format(size.w, size.h),
+        "-c:v", "rawvideo",
+        "-pix_fmt", "bgra",
+        "-f", "rawvideo",
+
+        "-y", output_path
+    }
+    return utils.subprocess({args=ffmpeg_command})
+end
+
+
+function check_output(ret, output_path, is_mpv)
+    local log_path = output_path .. ".log"
+    local success = true
+
+    if ret.killed_by_us then
+        return nil
+    else
+        if ret.error or ret.status ~= 0 then
+            msg.error("Thumbnailing command failed!")
+            msg.error("mpv process error:", ret.error)
+            msg.error("Process stdout:", ret.stdout)
+            if is_mpv then
+                msg.error("Debug log:", log_path)
+            end
+
+            success = false
+        end
+
+        if not file_exists(output_path) then
+            msg.error("Output file missing!", output_path)
+            success = false
+        end
+    end
+
+    if is_mpv and not thumbnailer_options.mpv_keep_logs then
+        -- Remove successful debug logs
+        if success and file_exists(log_path) then
+            os.remove(log_path)
+        end
+    end
+
+    return success
+end
+
+
+function do_worker_job(state_json_string, frames_json_string)
+    msg.debug("Handling given job")
+    local thumb_state, err = utils.parse_json(state_json_string)
+    if err then
+        msg.error("Failed to parse state JSON")
+        return
+    end
+
+    local thumbnail_indexes, err = utils.parse_json(frames_json_string)
+    if err then
+        msg.error("Failed to parse thumbnail frame indexes")
+        return
+    end
+
+    local thumbnail_func = create_thumbnail_mpv
+    if not thumbnailer_options.prefer_mpv then
+        if ExecutableFinder:get_executable_path("ffmpeg") then
+            thumbnail_func = create_thumbnail_ffmpeg
+        else
+            msg.warn("Could not find ffmpeg in PATH! Falling back on mpv.")
+        end
+    end
+
+    local file_duration = mp.get_property_native("duration")
+    local file_path = thumb_state.worker_input_path
+
+    if thumb_state.is_remote then
+        if (thumbnail_func == create_thumbnail_ffmpeg) then
+            msg.warn("Thumbnailing remote path, falling back on mpv.")
+        end
+        thumbnail_func = create_thumbnail_mpv
+    end
+
+    local generate_thumbnail_for_index = function(thumbnail_index)
+        -- Given a 1-based thumbnail index, generate a thumbnail for it based on the thumbnailer state
+        local thumb_idx = thumbnail_index - 1
+        msg.debug("Starting work on thumbnail", thumb_idx)
+
+        local thumbnail_path = thumb_state.thumbnail_template:format(thumb_idx)
+        -- Grab the "middle" of the thumbnail duration instead of the very start, and leave some margin in the end
+        local timestamp = math.min(file_duration - 0.25, (thumb_idx + 0.5) * thumb_state.thumbnail_delta)
+
+        mp.commandv("script-message", "mpv_thumbnail_script-progress", tostring(thumbnail_index))
+
+        -- The expected size (raw BGRA image)
+        local thumbnail_raw_size = (thumb_state.thumbnail_size.w * thumb_state.thumbnail_size.h * 4)
+
+        local need_thumbnail_generation = false
+
+        -- Check if the thumbnail already exists and is the correct size
+        local thumbnail_file = io.open(thumbnail_path, "rb")
+        if thumbnail_file == nil then
+            need_thumbnail_generation = true
+        else
+            local existing_thumbnail_filesize = thumbnail_file:seek("end")
+            if existing_thumbnail_filesize ~= thumbnail_raw_size then
+                -- Size doesn't match, so (re)generate
+                msg.warn("Thumbnail", thumb_idx, "did not match expected size, regenerating")
+                need_thumbnail_generation = true
+            end
+            thumbnail_file:close()
+        end
+
+        if need_thumbnail_generation then
+            local ret = thumbnail_func(file_path, timestamp, thumb_state.thumbnail_size, thumbnail_path, thumb_state.worker_extra)
+            local success = check_output(ret, thumbnail_path, thumbnail_func == create_thumbnail_mpv)
+
+            if success == nil then
+                -- Killed by us, changing files, ignore
+                msg.debug("Changing files, subprocess killed")
+                return true
+            elseif not success then
+                -- Real failure
+                mp.osd_message("Thumbnailing failed, check console for details", 3.5)
+                return true
+            end
+        else
+            msg.debug("Thumbnail", thumb_idx, "already done!")
+        end
+
+        -- Verify thumbnail size
+        -- Sometimes ffmpeg will output an empty file when seeking to a "bad" section (usually the end)
+        thumbnail_file = io.open(thumbnail_path, "rb")
+
+        -- Bail if we can't read the file (it should really exist by now, we checked this in check_output!)
+        if thumbnail_file == nil then
+            msg.error("Thumbnail suddenly disappeared!")
+            return true
+        end
+
+        -- Check the size of the generated file
+        local thumbnail_file_size = thumbnail_file:seek("end")
+        thumbnail_file:close()
+
+        -- Check if the file is big enough
+        local missing_bytes = math.max(0, thumbnail_raw_size - thumbnail_file_size)
+        if missing_bytes > 0 then
+            msg.warn(("Thumbnail missing %d bytes (expected %d, had %d), padding %s"):format(
+              missing_bytes, thumbnail_raw_size, thumbnail_file_size, thumbnail_path
+            ))
+            -- Pad the file if it's missing content (eg. ffmpeg seek to file end)
+            thumbnail_file = io.open(thumbnail_path, "ab")
+            thumbnail_file:write(string.rep(string.char(0), missing_bytes))
+            thumbnail_file:close()
+        end
+
+        msg.debug("Finished work on thumbnail", thumb_idx)
+        mp.commandv("script-message", "mpv_thumbnail_script-ready", tostring(thumbnail_index), thumbnail_path)
+    end
+
+    msg.debug(("Generating %d thumbnails @ %dx%d for %q"):format(
+        #thumbnail_indexes,
+        thumb_state.thumbnail_size.w,
+        thumb_state.thumbnail_size.h,
+        file_path))
+
+    for i, thumbnail_index in ipairs(thumbnail_indexes) do
+        local bail = generate_thumbnail_for_index(thumbnail_index)
+        if bail then return end
+    end
+
+end
+
+-- Set up listeners and keybinds
+
+-- Job listener
+mp.register_script_message("mpv_thumbnail_script-job", do_worker_job)
+
+
+-- Register this worker with the master script
+local register_timer = nil
+local register_timeout = mp.get_time() + 1.5
+
+local register_function = function()
+    if mp.get_time() > register_timeout and register_timer then
+        msg.error("Thumbnail worker registering timed out")
+        register_timer:stop()
+    else
+        msg.debug("Announcing self to master...")
+        mp.commandv("script-message", "mpv_thumbnail_script-worker", mp.get_script_name())
+    end
+end
+
+register_timer = mp.add_periodic_timer(0.1, register_function)
+
+mp.register_script_message("mpv_thumbnail_script-slaved", function()
+    msg.debug("Successfully registered with master")
+    register_timer:stop()
+end)

.config/mpv/scripts/mpv_thumbnail_script_server.lua

@@ -0,0 +1,736 @@
+--[[
+    Copyright (C) 2017 AMM
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+]]--
+--[[
+    mpv_thumbnail_script.lua 0.4.2 - commit 682becf (branch master)
+    https://github.com/TheAMM/mpv_thumbnail_script
+    Built on 2024-04-06 15:30:02
+]]--
+local assdraw = require 'mp.assdraw'
+local msg = require 'mp.msg'
+local opt = require 'mp.options'
+local utils = require 'mp.utils'
+
+-- Determine platform --
+ON_WINDOWS = (package.config:sub(1,1) ~= '/')
+
+-- Some helper functions needed to parse the options --
+function isempty(v) return (v == false) or (v == nil) or (v == "") or (v == 0) or (type(v) == "table" and next(v) == nil) end
+
+function divmod (a, b)
+  return math.floor(a / b), a % b
+end
+
+-- Better modulo
+function bmod( i, N )
+  return (i % N + N) % N
+end
+
+function join_paths(...)
+  local sep = ON_WINDOWS and "\\" or "/"
+  local result = "";
+  for i, p in pairs({...}) do
+    if p ~= "" then
+      if is_absolute_path(p) then
+        result = p
+      else
+        result = (result ~= "") and (result:gsub("[\\"..sep.."]*$", "") .. sep .. p) or p
+      end
+    end
+  end
+  return result:gsub("[\\"..sep.."]*$", "")
+end
+
+-- /some/path/file.ext -> /some/path, file.ext
+function split_path( path )
+  local sep = ON_WINDOWS and "\\" or "/"
+  local first_index, last_index = path:find('^.*' .. sep)
+
+  if last_index == nil then
+    return "", path
+  else
+    local dir = path:sub(0, last_index-1)
+    local file = path:sub(last_index+1, -1)
+
+    return dir, file
+  end
+end
+
+function is_absolute_path( path )
+  local tmp, is_win  = path:gsub("^[A-Z]:\\", "")
+  local tmp, is_unix = path:gsub("^/", "")
+  return (is_win > 0) or (is_unix > 0)
+end
+
+function Set(source)
+  local set = {}
+  for _, l in ipairs(source) do set[l] = true end
+  return set
+end
+
+---------------------------
+-- More helper functions --
+---------------------------
+
+-- Removes all keys from a table, without destroying the reference to it
+function clear_table(target)
+  for key, value in pairs(target) do
+    target[key] = nil
+  end
+end
+function shallow_copy(target)
+  local copy = {}
+  for k, v in pairs(target) do
+    copy[k] = v
+  end
+  return copy
+end
+
+-- Rounds to given decimals. eg. round_dec(3.145, 0) => 3
+function round_dec(num, idp)
+  local mult = 10^(idp or 0)
+  return math.floor(num * mult + 0.5) / mult
+end
+
+function file_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    local ok, err, code = f:read(1)
+    io.close(f)
+    return code == nil
+  else
+    return false
+  end
+end
+
+function path_exists(name)
+  local f = io.open(name, "rb")
+  if f ~= nil then
+    io.close(f)
+    return true
+  else
+    return false
+  end
+end
+
+function create_directories(path)
+  local cmd
+  if ON_WINDOWS then
+    cmd = { args = {"cmd", "/c", "mkdir", path} }
+  else
+    cmd = { args = {"mkdir", "-p", path} }
+  end
+  utils.subprocess(cmd)
+end
+
+-- Find an executable in PATH or CWD with the given name
+function find_executable(name)
+  local delim = ON_WINDOWS and ";" or ":"
+
+  local pwd = os.getenv("PWD") or utils.getcwd()
+  local path = os.getenv("PATH")
+
+  local env_path = pwd .. delim .. path -- Check CWD first
+
+  local result, filename
+  for path_dir in env_path:gmatch("[^"..delim.."]+") do
+    filename = join_paths(path_dir, name)
+    if file_exists(filename) then
+      result = filename
+      break
+    end
+  end
+
+  return result
+end
+
+local ExecutableFinder = { path_cache = {} }
+-- Searches for an executable and caches the result if any
+function ExecutableFinder:get_executable_path( name, raw_name )
+  name = ON_WINDOWS and not raw_name and (name .. ".exe") or name
+
+  if self.path_cache[name] == nil then
+    self.path_cache[name] = find_executable(name) or false
+  end
+  return self.path_cache[name]
+end
+
+-- Format seconds to HH.MM.SS.sss
+function format_time(seconds, sep, decimals)
+  decimals = decimals == nil and 3 or decimals
+  sep = sep and sep or "."
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  local second_format = string.format("%%0%d.%df", 2+(decimals > 0 and decimals+1 or 0), decimals)
+
+  return string.format("%02d"..sep.."%02d"..sep..second_format, h, m, s)
+end
+
+-- Format seconds to 1h 2m 3.4s
+function format_time_hms(seconds, sep, decimals, force_full)
+  decimals = decimals == nil and 1 or decimals
+  sep = sep ~= nil and sep or " "
+
+  local s = seconds
+  local h, s = divmod(s, 60*60)
+  local m, s = divmod(s, 60)
+
+  if force_full or h > 0 then
+    return string.format("%dh"..sep.."%dm"..sep.."%." .. tostring(decimals) .. "fs", h, m, s)
+  elseif m > 0 then
+    return string.format("%dm"..sep.."%." .. tostring(decimals) .. "fs", m, s)
+  else
+    return string.format("%." .. tostring(decimals) .. "fs", s)
+  end
+end
+
+-- Writes text on OSD and console
+function log_info(txt, timeout)
+  timeout = timeout or 1.5
+  msg.info(txt)
+  mp.osd_message(txt, timeout)
+end
+
+-- Join table items, ala ({"a", "b", "c"}, "=", "-", ", ") => "=a-, =b-, =c-"
+function join_table(source, before, after, sep)
+  before = before or ""
+  after = after or ""
+  sep = sep or ", "
+  local result = ""
+  for i, v in pairs(source) do
+    if not isempty(v) then
+      local part = before .. v .. after
+      if i == 1 then
+        result = part
+      else
+        result = result .. sep .. part
+      end
+    end
+  end
+  return result
+end
+
+function wrap(s, char)
+  char = char or "'"
+  return char .. s .. char
+end
+-- Wraps given string into 'string' and escapes any 's in it
+function escape_and_wrap(s, char, replacement)
+  char = char or "'"
+  replacement = replacement or "\\" .. char
+  return wrap(string.gsub(s, char, replacement), char)
+end
+-- Escapes single quotes in a string and wraps the input in single quotes
+function escape_single_bash(s)
+  return escape_and_wrap(s, "'", "'\\''")
+end
+
+-- Returns (a .. b) if b is not empty or nil
+function joined_or_nil(a, b)
+  return not isempty(b) and (a .. b) or nil
+end
+
+-- Put items from one table into another
+function extend_table(target, source)
+  for i, v in pairs(source) do
+    table.insert(target, v)
+  end
+end
+
+-- Creates a handle and filename for a temporary random file (in current directory)
+function create_temporary_file(base, mode, suffix)
+  local handle, filename
+  suffix = suffix or ""
+  while true do
+    filename = base .. tostring(math.random(1, 5000)) .. suffix
+    handle = io.open(filename, "r")
+    if not handle then
+      handle = io.open(filename, mode)
+      break
+    end
+    io.close(handle)
+  end
+  return handle, filename
+end
+
+
+function get_processor_count()
+  local proc_count
+
+  if ON_WINDOWS then
+    proc_count = tonumber(os.getenv("NUMBER_OF_PROCESSORS"))
+  else
+    local cpuinfo_handle = io.open("/proc/cpuinfo")
+    if cpuinfo_handle ~= nil then
+      local cpuinfo_contents = cpuinfo_handle:read("*a")
+      local _, replace_count = cpuinfo_contents:gsub('processor', '')
+      proc_count = replace_count
+    end
+  end
+
+  if proc_count and proc_count > 0 then
+      return proc_count
+  else
+    return nil
+  end
+end
+
+function substitute_values(string, values)
+  local substitutor = function(match)
+    if match == "%" then
+       return "%"
+    else
+      -- nil is discarded by gsub
+      return values[match]
+    end
+  end
+
+  local substituted = string:gsub('%%(.)', substitutor)
+  return substituted
+end
+
+-- ASS HELPERS --
+function round_rect_top( ass, x0, y0, x1, y1, r )
+  local c = 0.551915024494 * r -- circle approximation
+  ass:move_to(x0 + r, y0)
+  ass:line_to(x1 - r, y0) -- top line
+  if r > 0 then
+      ass:bezier_curve(x1 - r + c, y0, x1, y0 + r - c, x1, y0 + r) -- top right corner
+  end
+  ass:line_to(x1, y1) -- right line
+  ass:line_to(x0, y1) -- bottom line
+  ass:line_to(x0, y0 + r) -- left line
+  if r > 0 then
+      ass:bezier_curve(x0, y0 + r - c, x0 + r - c, y0, x0 + r, y0) -- top left corner
+  end
+end
+
+function round_rect(ass, x0, y0, x1, y1, rtl, rtr, rbr, rbl)
+    local c = 0.551915024494
+    ass:move_to(x0 + rtl, y0)
+    ass:line_to(x1 - rtr, y0) -- top line
+    if rtr > 0 then
+        ass:bezier_curve(x1 - rtr + rtr*c, y0, x1, y0 + rtr - rtr*c, x1, y0 + rtr) -- top right corner
+    end
+    ass:line_to(x1, y1 - rbr) -- right line
+    if rbr > 0 then
+        ass:bezier_curve(x1, y1 - rbr + rbr*c, x1 - rbr + rbr*c, y1, x1 - rbr, y1) -- bottom right corner
+    end
+    ass:line_to(x0 + rbl, y1) -- bottom line
+    if rbl > 0 then
+        ass:bezier_curve(x0 + rbl - rbl*c, y1, x0, y1 - rbl + rbl*c, x0, y1 - rbl) -- bottom left corner
+    end
+    ass:line_to(x0, y0 + rtl) -- left line
+    if rtl > 0 then
+        ass:bezier_curve(x0, y0 + rtl - rtl*c, x0 + rtl - rtl*c, y0, x0 + rtl, y0) -- top left corner
+    end
+end
+local SCRIPT_NAME = "mpv_thumbnail_script"
+
+local default_cache_base = ON_WINDOWS and os.getenv("TEMP") or "/tmp/"
+
+local thumbnailer_options = {
+    -- The thumbnail directory
+    cache_directory = join_paths(default_cache_base, "mpv_thumbs_cache"),
+
+    ------------------------
+    -- Generation options --
+    ------------------------
+
+    -- Automatically generate the thumbnails on video load, without a keypress
+    autogenerate = true,
+
+    -- Only automatically thumbnail videos shorter than this (seconds)
+    autogenerate_max_duration = 3600, -- 1 hour
+
+    -- SHA1-sum filenames over this length
+    -- It's nice to know what files the thumbnails are (hence directory names)
+    -- but long URLs may approach filesystem limits.
+    hash_filename_length = 128,
+
+    -- Use mpv to generate thumbnail even if ffmpeg is found in PATH
+    -- ffmpeg does not handle ordered chapters (MKVs which rely on other MKVs)!
+    -- mpv is a bit slower, but has better support overall (eg. subtitles in the previews)
+    prefer_mpv = true,
+
+    -- Explicitly disable subtitles on the mpv sub-calls
+    mpv_no_sub = false,
+    -- Add a "--no-config" to the mpv sub-call arguments
+    mpv_no_config = false,
+    -- Add a "--profile=<mpv_profile>" to the mpv sub-call arguments
+    -- Use "" to disable
+    mpv_profile = "",
+    -- Output debug logs to <thumbnail_path>.log, ala <cache_directory>/<video_filename>/000000.bgra.log
+    -- The logs are removed after successful encodes, unless you set mpv_keep_logs below
+    mpv_logs = true,
+    -- Keep all mpv logs, even the succesfull ones
+    mpv_keep_logs = false,
+
+    -- Disable the built-in keybind ("T") to add your own
+    disable_keybinds = false,
+
+    ---------------------
+    -- Display options --
+    ---------------------
+
+    -- Move the thumbnail up or down
+    -- For example:
+    --   topbar/bottombar: 24
+    --   rest: 0
+    vertical_offset = 24,
+
+    -- Adjust background padding
+    -- Examples:
+    --   topbar:       0, 10, 10, 10
+    --   bottombar:   10,  0, 10, 10
+    --   slimbox/box: 10, 10, 10, 10
+    pad_top   = 10,
+    pad_bot   =  0,
+    pad_left  = 10,
+    pad_right = 10,
+
+    -- If true, pad values are screen-pixels. If false, video-pixels.
+    pad_in_screenspace = true,
+    -- Calculate pad into the offset
+    offset_by_pad = true,
+
+    -- Background color in BBGGRR
+    background_color = "000000",
+    -- Alpha: 0 - fully opaque, 255 - transparent
+    background_alpha = 80,
+
+    -- Keep thumbnail on the screen near left or right side
+    constrain_to_screen = true,
+
+    -- Do not display the thumbnailing progress
+    hide_progress = false,
+
+    -----------------------
+    -- Thumbnail options --
+    -----------------------
+
+    -- The maximum dimensions of the thumbnails (pixels)
+    thumbnail_width = 200,
+    thumbnail_height = 200,
+
+    -- The thumbnail count target
+    -- (This will result in a thumbnail every ~10 seconds for a 25 minute video)
+    thumbnail_count = 150,
+
+    -- The above target count will be adjusted by the minimum and
+    -- maximum time difference between thumbnails.
+    -- The thumbnail_count will be used to calculate a target separation,
+    -- and min/max_delta will be used to constrict it.
+
+    -- In other words, thumbnails will be:
+    --   at least min_delta seconds apart (limiting the amount)
+    --   at most max_delta seconds apart (raising the amount if needed)
+    min_delta = 5,
+    -- 120 seconds aka 2 minutes will add more thumbnails when the video is over 5 hours!
+    max_delta = 90,
+
+
+    -- Overrides for remote urls (you generally want less thumbnails!)
+    -- Thumbnailing network paths will be done with mpv
+
+    -- Allow thumbnailing network paths (naive check for "://")
+    thumbnail_network = false,
+    -- Override thumbnail count, min/max delta
+    remote_thumbnail_count = 60,
+    remote_min_delta = 15,
+    remote_max_delta = 120,
+
+    -- Try to grab the raw stream and disable ytdl for the mpv subcalls
+    -- Much faster than passing the url to ytdl again, but may cause problems with some sites
+    remote_direct_stream = true,
+}
+
+read_options(thumbnailer_options, SCRIPT_NAME)
+function skip_nil(tbl)
+    local n = {}
+    for k, v in pairs(tbl) do
+        table.insert(n, v)
+    end
+    return n
+end
+
+function create_thumbnail_mpv(file_path, timestamp, size, output_path, options)
+    options = options or {}
+
+    local ytdl_disabled = not options.enable_ytdl and (mp.get_property_native("ytdl") == false
+                                                       or thumbnailer_options.remote_direct_stream)
+
+    local header_fields_arg = nil
+    local header_fields = mp.get_property_native("http-header-fields")
+    if #header_fields > 0 then
+        -- We can't escape the headers, mpv won't parse "--http-header-fields='Name: value'" properly
+        header_fields_arg = "--http-header-fields=" .. table.concat(header_fields, ",")
+    end
+
+    local profile_arg = nil
+    if thumbnailer_options.mpv_profile ~= "" then
+        profile_arg = "--profile=" .. thumbnailer_options.mpv_profile
+    end
+
+    local log_arg = "--log-file=" .. output_path .. ".log"
+
+    local mpv_command = skip_nil({
+        "mpv",
+        -- Hide console output
+        "--msg-level=all=no",
+
+        -- Disable ytdl
+        (ytdl_disabled and "--no-ytdl" or nil),
+        -- Pass HTTP headers from current instance
+        header_fields_arg,
+        -- Pass User-Agent and Referer - should do no harm even with ytdl active
+        "--user-agent=" .. mp.get_property_native("user-agent"),
+        "--referrer=" .. mp.get_property_native("referrer"),
+        -- Disable hardware decoding
+        "--hwdec=no",
+
+        -- Insert --no-config, --profile=... and --log-file if enabled
+        (thumbnailer_options.mpv_no_config and "--no-config" or nil),
+        profile_arg,
+        (thumbnailer_options.mpv_logs and log_arg or nil),
+
+        file_path,
+
+        "--start=" .. tostring(timestamp),
+        "--frames=1",
+        "--hr-seek=yes",
+        "--no-audio",
+        -- Optionally disable subtitles
+        (thumbnailer_options.mpv_no_sub and "--no-sub" or nil),
+
+        ("--vf=scale=%d:%d"):format(size.w, size.h),
+        "--vf-add=format=bgra",
+        "--of=rawvideo",
+        "--ovc=rawvideo",
+        "--o=" .. output_path
+    })
+    return utils.subprocess({args=mpv_command})
+end
+
+
+function create_thumbnail_ffmpeg(file_path, timestamp, size, output_path)
+    local ffmpeg_command = {
+        "ffmpeg",
+        "-loglevel", "quiet",
+        "-noaccurate_seek",
+        "-ss", format_time(timestamp, ":"),
+        "-i", file_path,
+
+        "-frames:v", "1",
+        "-an",
+
+        "-vf", ("scale=%d:%d"):format(size.w, size.h),
+        "-c:v", "rawvideo",
+        "-pix_fmt", "bgra",
+        "-f", "rawvideo",
+
+        "-y", output_path
+    }
+    return utils.subprocess({args=ffmpeg_command})
+end
+
+
+function check_output(ret, output_path, is_mpv)
+    local log_path = output_path .. ".log"
+    local success = true
+
+    if ret.killed_by_us then
+        return nil
+    else
+        if ret.error or ret.status ~= 0 then
+            msg.error("Thumbnailing command failed!")
+            msg.error("mpv process error:", ret.error)
+            msg.error("Process stdout:", ret.stdout)
+            if is_mpv then
+                msg.error("Debug log:", log_path)
+            end
+
+            success = false
+        end
+
+        if not file_exists(output_path) then
+            msg.error("Output file missing!", output_path)
+            success = false
+        end
+    end
+
+    if is_mpv and not thumbnailer_options.mpv_keep_logs then
+        -- Remove successful debug logs
+        if success and file_exists(log_path) then
+            os.remove(log_path)
+        end
+    end
+
+    return success
+end
+
+
+function do_worker_job(state_json_string, frames_json_string)
+    msg.debug("Handling given job")
+    local thumb_state, err = utils.parse_json(state_json_string)
+    if err then
+        msg.error("Failed to parse state JSON")
+        return
+    end
+
+    local thumbnail_indexes, err = utils.parse_json(frames_json_string)
+    if err then
+        msg.error("Failed to parse thumbnail frame indexes")
+        return
+    end
+
+    local thumbnail_func = create_thumbnail_mpv
+    if not thumbnailer_options.prefer_mpv then
+        if ExecutableFinder:get_executable_path("ffmpeg") then
+            thumbnail_func = create_thumbnail_ffmpeg
+        else
+            msg.warn("Could not find ffmpeg in PATH! Falling back on mpv.")
+        end
+    end
+
+    local file_duration = mp.get_property_native("duration")
+    local file_path = thumb_state.worker_input_path
+
+    if thumb_state.is_remote then
+        if (thumbnail_func == create_thumbnail_ffmpeg) then
+            msg.warn("Thumbnailing remote path, falling back on mpv.")
+        end
+        thumbnail_func = create_thumbnail_mpv
+    end
+
+    local generate_thumbnail_for_index = function(thumbnail_index)
+        -- Given a 1-based thumbnail index, generate a thumbnail for it based on the thumbnailer state
+        local thumb_idx = thumbnail_index - 1
+        msg.debug("Starting work on thumbnail", thumb_idx)
+
+        local thumbnail_path = thumb_state.thumbnail_template:format(thumb_idx)
+        -- Grab the "middle" of the thumbnail duration instead of the very start, and leave some margin in the end
+        local timestamp = math.min(file_duration - 0.25, (thumb_idx + 0.5) * thumb_state.thumbnail_delta)
+
+        mp.commandv("script-message", "mpv_thumbnail_script-progress", tostring(thumbnail_index))
+
+        -- The expected size (raw BGRA image)
+        local thumbnail_raw_size = (thumb_state.thumbnail_size.w * thumb_state.thumbnail_size.h * 4)
+
+        local need_thumbnail_generation = false
+
+        -- Check if the thumbnail already exists and is the correct size
+        local thumbnail_file = io.open(thumbnail_path, "rb")
+        if thumbnail_file == nil then
+            need_thumbnail_generation = true
+        else
+            local existing_thumbnail_filesize = thumbnail_file:seek("end")
+            if existing_thumbnail_filesize ~= thumbnail_raw_size then
+                -- Size doesn't match, so (re)generate
+                msg.warn("Thumbnail", thumb_idx, "did not match expected size, regenerating")
+                need_thumbnail_generation = true
+            end
+            thumbnail_file:close()
+        end
+
+        if need_thumbnail_generation then
+            local ret = thumbnail_func(file_path, timestamp, thumb_state.thumbnail_size, thumbnail_path, thumb_state.worker_extra)
+            local success = check_output(ret, thumbnail_path, thumbnail_func == create_thumbnail_mpv)
+
+            if success == nil then
+                -- Killed by us, changing files, ignore
+                msg.debug("Changing files, subprocess killed")
+                return true
+            elseif not success then
+                -- Real failure
+                mp.osd_message("Thumbnailing failed, check console for details", 3.5)
+                return true
+            end
+        else
+            msg.debug("Thumbnail", thumb_idx, "already done!")
+        end
+
+        -- Verify thumbnail size
+        -- Sometimes ffmpeg will output an empty file when seeking to a "bad" section (usually the end)
+        thumbnail_file = io.open(thumbnail_path, "rb")
+
+        -- Bail if we can't read the file (it should really exist by now, we checked this in check_output!)
+        if thumbnail_file == nil then
+            msg.error("Thumbnail suddenly disappeared!")
+            return true
+        end
+
+        -- Check the size of the generated file
+        local thumbnail_file_size = thumbnail_file:seek("end")
+        thumbnail_file:close()
+
+        -- Check if the file is big enough
+        local missing_bytes = math.max(0, thumbnail_raw_size - thumbnail_file_size)
+        if missing_bytes > 0 then
+            msg.warn(("Thumbnail missing %d bytes (expected %d, had %d), padding %s"):format(
+              missing_bytes, thumbnail_raw_size, thumbnail_file_size, thumbnail_path
+            ))
+            -- Pad the file if it's missing content (eg. ffmpeg seek to file end)
+            thumbnail_file = io.open(thumbnail_path, "ab")
+            thumbnail_file:write(string.rep(string.char(0), missing_bytes))
+            thumbnail_file:close()
+        end
+
+        msg.debug("Finished work on thumbnail", thumb_idx)
+        mp.commandv("script-message", "mpv_thumbnail_script-ready", tostring(thumbnail_index), thumbnail_path)
+    end
+
+    msg.debug(("Generating %d thumbnails @ %dx%d for %q"):format(
+        #thumbnail_indexes,
+        thumb_state.thumbnail_size.w,
+        thumb_state.thumbnail_size.h,
+        file_path))
+
+    for i, thumbnail_index in ipairs(thumbnail_indexes) do
+        local bail = generate_thumbnail_for_index(thumbnail_index)
+        if bail then return end
+    end
+
+end
+
+-- Set up listeners and keybinds
+
+-- Job listener
+mp.register_script_message("mpv_thumbnail_script-job", do_worker_job)
+
+
+-- Register this worker with the master script
+local register_timer = nil
+local register_timeout = mp.get_time() + 1.5
+
+local register_function = function()
+    if mp.get_time() > register_timeout and register_timer then
+        msg.error("Thumbnail worker registering timed out")
+        register_timer:stop()
+    else
+        msg.debug("Announcing self to master...")
+        mp.commandv("script-message", "mpv_thumbnail_script-worker", mp.get_script_name())
+    end
+end
+
+register_timer = mp.add_periodic_timer(0.1, register_function)
+
+mp.register_script_message("mpv_thumbnail_script-slaved", function()
+    msg.debug("Successfully registered with master")
+    register_timer:stop()
+end)