Posted using AHK Studio

youtube.ahk

#SingleInstance,Force
html:=ComObjCreate("htmlfile")
url:="https://www.youtube.com/watch?v=VZZ0PnDZdZk"
html.write(URLDownloadToVar(url))
title:=html.getElementsByName("title").item[0].getattribute("content")
title1:=title
title:=uriencode(title)
scripts:=html.getElementsBytagname("script") ;.length ;.innerhtml ;.getattribute("flashvars")
while,ss:=scripts.item[A_Index-1]{
	if InStr(ss.innerhtml,"bitrate"){
		for a,b in StrSplit(ss.innerhtml,",")
		if InStr(b,"bitrate"){
			url:=""
			RegExMatch(uridecode(b),"(http.*)",found)
			for a,b in StrSplit(found,"&"){
				if InStr(b,"\u")
					url.=RegExReplace(b,"U)\\u\d\d\d\d","&") ""
				else
					url.=b "&"
			}
			url1:=""
			for a,b in StrSplit(url,"&"){
				if b not contains fallback_host,type,quality
					url1.=b "&"
			}
			download:
			URLDownloadToFile,% url1,%title1%.mp4
			FileGetSize,size,%title1%.mp4
			if (size<100){
				
				m("Did not download, trying again")
				goto download
			}
			Else
				break
		}
		m("done",info,url,ss.innerhtml)
		break
	}
}
return
UriEncode(Uri){
	Len:=StrPut(uri,"utf-8"),VarSetCapacity(Var,Len,0),StrPut(uri, &Var, Enc),f:=A_FormatInteger
	SetFormat, IntegerFast, H
	Loop
	{
		Code := NumGet(Var,A_Index-1,"UChar")
		If (!Code)
			Break
		If (Code>=0x30&&Code<=0x39||Code>=0x41&&Code<=0x5A||Code>=0x61&&Code<=0x7A)
			Res.=Chr(Code)
		Else
			Res .= "%" SubStr(Code + 0x100, -1)
	}
	SetFormat,IntegerFast,%f%
	Return,Res
}
m(x*){
	for a,b in x
		list.=b "`n"
	msgbox %list%
}

uriDecode(str) {
	Loop
		If RegExMatch(str, "i)(?<=%)[\da-f]{1,2}", hex)
			StringReplace, str, str, `%%hex%, % Chr("0x" . hex), All
	Else Break
		Return, str
}
URLDownloadToVar( url )
{
	hObject:=ComObjCreate("WinHttp.WinHttpRequest.5.1")
	hObject.Open("GET", url)
	hObject.Send()
	return hObject.ResponseText
}