VLC - Playlist Parser for Twitch streams/videos URLs

frs-vlc_twitch.lua

--[[
	Resolve Twitch channel and video URLs to the actual media URL
	Author: furious

  How to install? https://wiki.videolan.org/Documentation:Building_Lua_Playlist_Scripts
  Don't forget to remove the old "twitch.luac" plugin

	OBS: You can choose which quality you want just add ":option" in the url.
	If the option isn't available it will fallback to the best quality as normal.
	You can also check the console log to see all available quality options.
	
	Common options: chunked (default), 1080p, 720p60, 720p30, 480p, 360, audio_only
	
	Example: http://twitch.tv/furious:480
--]]

-- Probe function
function probe()
	return (vlc.access == "http" or vlc.access == "https")
		and ( vlc.path:match("^www%.twitch%.tv/videos/.+") or
			  vlc.path:match("^www%.twitch%.tv/.+") or
			  vlc.path:match("^go%.twitch%.tv/.+") or 
			  vlc.path:match("^go%.twitch%.tv/videos/.+") )
end

-- Download and parse a JSON document from the specified URL
-- Returns: obj, pos, err (see dkjson docs)
function parse_json(url)
	local json   = require("dkjson")
	local stream = vlc.stream(url)
	local string = ""
	local line   = ""

	if not stream then
		return nil, nil, "Failed creating VLC stream"
	end

	while true do
		line = stream:readline()

		if not line then
			break
		end

		string = string .. line
	end

	return json.decode(string)
end

-- Download and parse a M3U8 document from the specified URL
-- Returns: obj, pos, err
function parse_m3u8(url)
	local json   = require("dkjson")
	local stream = vlc.stream(url)
	local line   = ""
	local options = {}

	if not stream then
		return nil, nil, "Failed creating VLC stream"
	end

	while true do
		line = stream:readline()

		if not line then
			break
		end

		if string.match(line, 'EXT--X--MEDIA:TYPE') ~= nil then
			local option = {}
			option.id, option.name = string.match(line, "GROUP--ID\=\"([^\"]+)\",NAME\=\"([^\"]+)\"")
			vlc.msg.info("[Twitch] Quality Available: " .. option.id .. " - " .. option.name)
			line = stream:readline()
			option.resolution, option.codecs = string.match(line, "RESOLUTION\=([^,]+),CODECS\=\"([^\"]+)\"")
			option.playlist = stream:readline()
			if option.resolution then
				options[option.id] = option
			end
		end
	end

	--if not next(options) then
	--    return nil, nil, "No quality options available"
	--end

	return options
end

-- Make a request to the Twitch API endpoint given by url
-- Returns: obj, err
function twitch_api_req(url)
	local obj, pos, err = parse_json(url .. "?client_id=1ht9oitznxzdo3agmdbn3dydbm06q2")

	if err then
		return nil, "Error getting JSON object: " .. err
	end

	-- In case of error, the API will return an object with
	-- error and message given
	if obj.error then
		local err = "Twitch API error: " .. obj.error
		if obj.message then
			err = err .. " (" .. obj.message .. ")"
		end
		return nil, err
	end

	return obj, nil
end

-- Parser for twitch video urls
function parse_video()
	local playlist = {}
	local item = {}
	local url, obj, err = nil

	-- Parse video id out of url
	local video_id = vlc.path:match("/videos/(%d+)")
	local quality = vlc.path:match(":([a-zA-Z0-9_]+)")

	if video_id == nil then
		vlc.msg.err("Twitch: Failed to parse twitch url for video id")
		return playlist
	end

	vlc.msg.dbg("Twitch: Loading video url for " .. video_id)

	-- Request video token (required for the video stream)
	url = "https://api.twitch.tv/api/vods/" ..  video_id .. "/access_token"
	obj, err = twitch_api_req(url)

	if err then
		vlc.msg.err("Error getting request token from Twitch: " .. err)
		return playlist
	end

	-- Construct stream url
	local stream_url = "http://usher.twitch.tv/vod/" .. video_id
	stream_url = stream_url .. "?player=twitchweb"
	stream_url = stream_url .. "&nauth=" .. vlc.strings.encode_uri_component(obj.token)
	stream_url = stream_url .. "&nauthsig=" .. obj.sig
	stream_url = stream_url .. "&allow_audio_only=true&allow_source=true"

	local options, pos, err = parse_m3u8(stream_url)
	if err then
		vlc.msg.err("Error parsing m3u8 playlist: " .. err)
		return playlist
	end

	item["path"]   = stream_url

	if quality then
		for option, info in pairs(options) do
			if string.find(info.id, quality) or string.find(info.name, quality) then
				item["path"] = info.playlist
				quality = info.name
			end
		end
	else
		info = next(options)
		item["path"] = info.playlist
		quality = info.name
	end

	-- Set base information
	item["name"] = "Twitch: " .. video_id .. "[" .. quality .. "]"

	-- Request video information
	url = "https://api.twitch.tv/kraken/videos/v" .. video_id
	obj, err = twitch_api_req(url)

	if err then
		vlc.msg.warn("Error getting video info from Twitch: " .. err)
		table.insert(playlist, item)
		return playlist
	end

	-- Overwrite with now obtained better info
	item["name"]        = "Twitch: " .. obj.title .. "[" .. quality .. "]"
	item["artist"]      = obj.channel.display_name
	item["description"] = obj.description
	item["url"]         = vlc.path

	table.insert(playlist, item)

	return playlist
end

-- Parser for twitch stream urls
function parse_stream()
	local playlist = {}
	local item = {}
	local url, obj, err = nil

	-- Parse channel name out of url
	local channel = vlc.path:match("/([a-zA-Z0-9_]+)")
	local quality = vlc.path:match(":([a-zA-Z0-9_]+)")

	if channel == nil then
		vlc.msg.err("Twitch: Failed to parse twitch url for channel name")
		return playlist
	end

	vlc.msg.dbg("Twitch: Loading stream url for " .. channel)

	-- Request channel token (required for the stream m3u8)
	url = "https://api.twitch.tv/api/channels/" .. channel .. "/access_token"
	obj, err = twitch_api_req(url)

	if err then
		vlc.msg.err("Error getting request token from Twitch: " .. err)
		return playlist
	end

	-- Construct stream url
	local stream_url = "http://usher.twitch.tv/api/channel/hls/" .. channel .. ".m3u8"
	stream_url = stream_url .. "?player=twitchweb"
	stream_url = stream_url .. "&token=" .. vlc.strings.encode_uri_component(obj.token)
	stream_url = stream_url .. "&sig=" .. obj.sig
	stream_url = stream_url .. "&allow_audio_only=true&allow_source=true&type=any"


	local options, pos, err = parse_m3u8(stream_url)
	if err then
		vlc.msg.err("Error parsing m3u8 playlist: " .. err)
		return playlist
	end

	item["path"]   = stream_url

	if quality then
		for option, info in pairs(options) do
			if string.find(info.id, quality) or string.find(info.name, quality) then
				item["path"] = info.playlist
				quality = info.name
			end
		end
	else
		info = next(options)
		item["path"] = info.playlist
		quality = info.name
	end

	-- Set base information
	item["name"]   = "Twitch: Stream [" .. quality .. "]"
	item["artist"] = channel

	-- Request channel information
	url = "https://api.twitch.tv/api/channels/" .. channel
	obj, err = twitch_api_req(url)

	if err then
		vlc.msg.warn("Error getting channel info from Twitch: " .. err)
		table.insert(playlist, item)
		return playlist
	end

	-- Overwrite with now obtained better info
	item["name"]        = "Twitch: Stream [" .. quality .. "]"
	item["nowplaying"]  = obj.display_name .. " playing " .. obj.game
	item["artist"]      = obj.display_name
	item["description"] = obj.status 
	item["url"]         = vlc.path

	table.insert(playlist, item)

	return playlist
end

-- Parse function
function parse()
	if vlc.path:match("/videos/.+") then
		return parse_video()
	else
		return parse_stream()
	end
end