I have Youtube direct link like: http://www.youtube.com/watch?v=gmbjSvWhp48
I want to get the stream url to download this video, the stream url looks like: http://r5---sn-8qj-i5oz.googlevideo.com/videoplayback?app=youtube_mobile&upn=Cz_UBAXUYPc&ip=113.190.227.224&key=yt5&ipbits=0&ratebypass=yes&source=youtube&sparams=id%2Cip%2Cipbits%2Citag%2Cratebypass%2Csource%2Cupn%2Cexpire&el=watch&id=15e7f026685672db&yms=8CYHy94BUPw&ms=au&mt=1386558301&fexp=941262%2C936912%2C936910%2C923305%2C936913%2C907231%2C907240&itag=18&dnc=1&mv=m&expire=1386582066&sver=3&signature=497EAB4477F77C7B9E50A9018F8642B9D028A10F.EFC8DD3E5C27597F8069A5A4CBD09293FF263383
So how do I get this link?
