[synopeas]

There should be url starting "http://www.youtube.com/api/manifest/hls_variant/". That's the one you want to find.
I use Firefox17 with CacheViewer Continued addon to retrieve the file from the browser cache. Then you'll be able to see the complete url for the stream you want.
The url you just posted is incomplete and for the lowest bandwidth. It should end with .m3u8

For now try this:-

ffmpeg -i "http://www.youtube.com/api/manifest/hls_playlist/id/p8KFjGLe1CU.1/itag/95/source/yt_live_broadcast/ratebypass/yes/live/1/cmbypass/yes/newshard/yes/gir/yes/playlist_type/LIVE/maudio/1/pmbypass/yes/cp/U0hVSVFSVl9LTUNONV9JTFpDOjBzYTdhRzkyejc5/sver/3/upn/gM4RDZbXIl0/fexp/902000,919512,913605,931202,900821,900823,931203,9 31401,908529,930803,920201,929602,930101,930603,90 0824,910223/cpn/Bby-sOIwQbPcGy3d/ip/*.*.*.*/ipbits/8/expire/1364178263/sparams/ip,ipbits,expire,id,itag,source,ratebypass,live,cm bypass,newshard,gir,playlist_type,maudio,pmbypass, cp/signature/37A0AB53D3216643F24C8792DF2937E12DCD6685.24C0B67A0 722FCDF88CA5F9CC7A2725889800B87/key/dg_yt0/file/index.m3u8" -c copy seg.ts

Put your ip address in place of the 4 stars.