AMSSpecialist

function ExtractYouTube()
local sBody = GetBody(Input.GetText("name_input"));
local url_map = string.match( sBody, "\"url_encoded_fmt_stream_map\": \"(.-)\"" );
url_map = string.gsub( url_map, "\\u0026", "&" );
  for stream in string.gmatch( url_map, "[^,]+" ) do
  local url = string.match( stream, "url=([^&,]+)" );
  local sig = string.match( stream, "s=([^&,]+)" );
    if ( string.find(unescape(url), "itag=137") ) then
    return unescape(url).."&signature="..sig;
    else
    local url_map = string.match( sBody, "adaptive_fmts\": \"(.-)\"" );
    url_map = string.gsub( url_map, "\\u0026", "&" );
      for stream in string.gmatch( url_map, "[^,]+" ) do
      local url = string.match( stream, "url=([^&,]+)" );
      local sig = string.match( stream, "s=([^&,]+)" );
        if ( string.find(unescape(url), "itag=137") ) then
        return unescape(url).."&signature="..sig;
        end
      end
    end
  end
end