mp = require 'mp'

local decode_needed = false

function trim(s)
   return (s:gsub("^%s*(.-)%s*$", "%1"))
end

function decode(title)
    local ret = io.popen(string.format('%s "%s" | %s',
        'echo', title, 'iconv -f="windows-1251" -t="utf-8"')):read('*all')

    return trim(ret)
end

function on_title_changed(name, title)
    if decode_needed then
        local decoded = decode(title)
        print(title, '->', decoded)
        mp.set_property('force-media-title', decoded)
    end
end

mp.observe_property('media-title', 'string', on_title_changed)
mp.add_hook('on_load', 50, function()
        local filename = mp.get_property('path', nil)
        decode_needed =  string.find(filename, 'ru')
    end)