normal.js

// # node-YouTubeStreamer
// _by Licson Lee <licson0729@gmail.com>_
//
// This is the normal streaming module for node-YouTubeStreamer.

//Require the libraries needed.
var request = require('request');
var qs = require('querystring');
var spawn = require('child_process').spawn;

//Here's our normal stream handler.
module.exports = function(query, data, options){
	//Get the streams from the API response
	var streams = String(data.url_encoded_fmt_stream_map).split(',');
	//Loop througn all streams
	for(var i = 0; i < streams.length; i++){
		//Parse the stream
		var stream = qs.parse(streams[i]);
		//If the stream is compatable with the video type,
		//we return a function that can stream the video to the client.
		//Note: we **DO NOT** stream HD videos to save bandwidth.
		if(String(stream.type).indexOf(query.type) > -1
			&& (
					//Should we stream HD videos?
					//When using audio conversion, we force the stream not to be
					//in HD to reduce processing times
					(options.useHDVideos
						&& (
							!!query.audio
							&& options.convertAudio	
						)
					) ? 
					(
						true
					) :
					
					//stream regular quality videos
					(
						stream.quality == "large" 
						|| stream.quality == "medium"
						|| stream.quality == "small"
					)
				)
		){
			return function(res){
				//Convert video to audio in real-time using FFMpeg
				if(!!query.audio && options.convertAudio){
					var ffmpeg = spawn('ffmpeg',['-i','-','-vn','-ac',2,'-ar',44100,'-ab','128k','-f','mp3','-']);
					var video = request(stream.url+'&signature=' + (stream.sig || stream.s));
					
					res.writeHead(200,{
						'Content-type': 'audio/mpeg'
					});
					
					ffmpeg.stdout.on('end', function(){
						ffmpeg.kill();
					});
					
					video.pipe(ffmpeg.stdin);
					ffmpeg.stdout.pipe(res);
					return;
				}
				
				//Pipe the stream out
				request(stream.url + '&signature=' + (stream.sig || stream.s)).pipe(res);
			};
		}
	}
	
	//No streams can be found with the format specified
	//Return an error message
	return function(res){
		res.end("No compatable streams can be found!");
	};
};