--[[
$Id$
Copyright © 2007-2013 the VideoLAN team
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 2 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, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
--]]
-- Helper function to get a parameter's value in a URL
function get_url_param( url, name )
local _, _, res = string.find( url, "[&?]"..name.."=([^&]*)" )
return res
end
function get_arturl()
local iurl = get_url_param( vlc.path, "iurl" )
if iurl then
return iurl
end
local video_id = get_url_param( vlc.path, "v" )
if not video_id then
return nil
end
return "http://img.youtube.com/vi/"..video_id.."/default.jpg"
end
function get_prefres()
local prefres = -1
if vlc.var and vlc.var.inherit then
prefres = vlc.var.inherit(nil, "preferred-resolution")
if prefres == nil then
prefres = -1
end
end
return prefres
end
-- Pick the most suited format available
function get_fmt( fmt_list )
local prefres = get_prefres()
if prefres < 0 then
return nil
end
local fmt = nil
for itag,height in string.gmatch( fmt_list, "(%d+)/%d+x(%d+)/[^,]+" ) do
-- Apparently formats are listed in quality
-- order, so we take the first one that works,
-- or fallback to the lowest quality
fmt = itag
if tonumber(height) <= prefres then
break
end
end
return fmt
end
-- Descramble the URL signature using the javascript code that does that
-- in the web page
function js_descramble( sig, js_url )
-- Fetch javascript code
local js = vlc.stream( js_url )
if not js then
return sig
end
local lines = {}
-- Look for the descrambler function's name
local descrambler = nil
while not descrambler do
local line = js:readline()
if not line then
vlc.msg.err( "Couldn't process youtube video URL, please check for updates to this script" )
return sig
end
-- Buffer lines for later, so we don't have to make a second
-- HTTP request later
table.insert( lines, line )
-- c&&(b.signature=ij(c));
-- descrambler = string.match( line, "%.signature=(.-)%(" )
-- descrambler = string.match( line, "%.sig%|%|(.-)%(" )
descrambler = string.match( line, "%.sig||([a-zA-Z0-9]+)%(" )
end
-- Fetch the code of the descrambler function. The function is
-- conveniently preceded by the definition of a helper object
-- that it uses. Example:
-- var Fo={TR:function(a){a.reverse()},TU:function(a,b){var c=a[0];a[0]=a[b%a.length];a[b]=c},sH:function(a,b){a.splice(0,b)}};function Go(a){a=a.split("");Fo.sH(a,2);Fo.TU(a,28);Fo.TU(a,44);Fo.TU(a,26);Fo.TU(a,40);Fo.TU(a,64);Fo.TR(a,26);Fo.sH(a,1);return a.join("")};
local transformations = nil
local rules = nil
while not transformations and not rules do
local line
if #lines > 0 then
line = table.remove( lines )
else
line = js:readline()
if not line then
vlc.msg.err( "Couldn't process youtube video URL, please check for updates to this script" )
return sig
end
end
transformations, rules = string.match( line, "var ..={(.-)};function "..descrambler.."%([^)]*%){(.-)}" )
end
-- Parse the helper object to map available transformations
local trans = {}
for meth,code in string.gmatch( transformations, "(..):function%([^)]*%){([^}]*)}" ) do
-- a=a.reverse()
if string.match( code, "%.reverse%(" ) then
trans[meth] = "reverse"
-- a.splice(0,b)
elseif string.match( code, "%.splice%(") then
trans[meth] = "slice"
-- var c=a[0];a[0]=a[b%a.length];a[b]=c
elseif string.match( code, "var c=" ) then
trans[meth] = "swap"
else
vlc.msg.warn("Couldn't parse unknown youtube video URL signature transformation")
end
end
-- Parse descrambling rules, map them to known transformations
-- and apply them on the signature
local missing = false
for meth,idx in string.gmatch( rules, "..%.(..)%([^,]+,(%d+)%)" ) do
idx = tonumber( idx )
if trans[meth] == "reverse" then
sig = string.reverse( sig )
elseif trans[meth] == "slice" then
sig = string.sub( sig, idx + 1 )
elseif trans[meth] == "swap" then
if idx > 1 then
sig = string.gsub( sig, "^(.)("..string.rep( ".", idx - 1 )..")(.)(.*)$", "%3%2%1%4" )
elseif idx == 1 then
sig = string.gsub( sig, "^(.)(.)", "%2%1" )
end
else
vlc.msg.dbg("Couldn't apply unknown youtube video URL signature transformation")
missing = true
end
end
if missing then
vlc.msg.err( "Couldn't process youtube video URL, please check for updates to this script" )
end
return sig
end
-- Parse and pick our video URL
function pick_url( url_map, fmt, js_url )
local path = nil
for stream in string.gmatch( url_map, "[^,]+" ) do
-- Apparently formats are listed in quality order,
-- so we can afford to simply take the first one
local itag = string.match( stream, "itag=(%d+)" )
if not fmt or not itag or tonumber( itag ) == tonumber( fmt ) then
local url = string.match( stream, "url=([^&,]+)" )
if url then
url = vlc.strings.decode_uri( url )
local sig = string.match( stream, "sig=([^&,]+)" )
if not sig then
-- Scrambled signature
sig = string.match( stream, "s=([^&,]+)" )
if sig then
vlc.msg.dbg( "Found "..string.len( sig ).."-character scrambled signature for youtube video URL, attempting to descramble... " )
if js_url then
sig = js_descramble( sig, js_url )
else
vlc.msg.err( "Couldn't process youtube video URL, please check for updates to this script" )
end
end
end
local signature = ""
if sig then
signature = "&signature="..sig
end
path = url..signature
break
end
end
end
return path
end
-- Probe function.
function probe()
if vlc.access ~= "http" and vlc.access ~= "https" then
return false
end
youtube_site = string.match( string.sub( vlc.path, 1, 8 ), "youtube" )
if not youtube_site then
-- FIXME we should be using a builtin list of known youtube websites
-- like "fr.youtube.com", "uk.youtube.com" etc..
youtube_site = string.find( vlc.path, ".youtube.com" )
if youtube_site == nil then
return false
end
end
return ( string.match( vlc.path, "/watch%?" ) -- the html page
or string.match( vlc.path, "/get_video_info%?" ) -- info API
or string.match( vlc.path, "/v/" ) -- video in swf player
or string.match( vlc.path, "/embed/" ) -- embedded player iframe
or string.match( vlc.path, "/player2.swf" ) ) -- another player url
end
-- Parse function.
function parse()
if string.match( vlc.path, "/watch%?" )
then -- This is the HTML page's URL
-- fmt is the format of the video
-- (cf. http://en.wikipedia.org/wiki/YouTube#Quality_and_codecs)
fmt = get_url_param( vlc.path, "fmt" )
while true do
-- Try to find the video's title
line = vlc.readline()
if not line then break end
if string.match( line, "]*>([^<]*)" )
if artist then
artist = vlc.strings.resolve_xml_special_chars( artist )
end
end
-- JSON parameters, also formerly known as "swfConfig",
-- "SWF_ARGS", "swfArgs", "PLAYER_CONFIG", "playerConfig" ...
if string.match( line, "ytplayer%.config" ) then
local js_url = string.match( line, "\"js\": \"(.-)\"" )
if js_url then
js_url = string.gsub( js_url, "\\/", "/" )
js_url = string.gsub( js_url, "^//", vlc.access.."://" )
end
if not fmt then
fmt_list = string.match( line, "\"fmt_list\": \"(.-)\"" )
if fmt_list then
fmt_list = string.gsub( fmt_list, "\\/", "/" )
fmt = get_fmt( fmt_list )
end
end
url_map = string.match( line, "\"url_encoded_fmt_stream_map\": \"(.-)\"" )
if url_map then
-- FIXME: do this properly
url_map = string.gsub( url_map, "\\u0026", "&" )
path = pick_url( url_map, fmt, js_url )
end
if not path then
-- If this is a live stream, the URL map will be empty
-- and we get the URL from this field instead
local hlsvp = string.match( line, "\"hlsvp\": \"(.-)\"" )
if hlsvp then
hlsvp = string.gsub( hlsvp, "\\/", "/" )
path = hlsvp
end
end
-- There is also another version of the parameters, encoded
-- differently, as an HTML attribute of an