Estos son los codigos que estoy usando, usando como enlace este:
enlace:
CON WGET:
Cita: exec("wget http://o-o.preferred.dfw06s10.v15.lscache2.c.youtube.com/videoplayback?sparams=id%2Cexpire%2Cip%2Cipbits%2C itag%2Csource%2Cratebypass%2Ccp&fexp=906012&itag=4 3&ip=81.0.0.0&signature=485770E7F4C29FA3E46C6A34BE 983933735803C0.4CB939AF065CF5069D223ACDB784AFE84D8 18F1B&sver=3&ratebypass=yes&source=youtube&expire= 1324944666&key=yt1&ipbits=8&cp=U0hRSVlPUl9LUENOMV9 RSVZHOlFSSTR3eUp6Qnp5&id=bfac54f7a28b04be");
CON FORZAR DESCARGA DE PHP
Cita: $file = "http://o-o.preferred.dfw06s10.v15.lscache2.c.youtube.com/videoplayback?sparams=id%2Cexpire%2Cip%2Cipbits%2C itag%2Csource%2Cratebypass%2Ccp&fexp=906012&itag=4 3&ip=81.0.0.0&signature=485770E7F4C29FA3E46C6A34BE 983933735803C0.4CB939AF065CF5069D223ACDB784AFE84D8 18F1B&sver=3&ratebypass=yes&source=youtube&expire= 1324944666&key=yt1&ipbits=8&cp=U0hRSVlPUl9LUENOMV9 RSVZHOlFSSTR3eUp6Qnp5&id=bfac54f7a28b04be/.flv";
$fichero = trim(addslashes(strip_tags($file)));
$filename = "Romans/$fichero";
header("Content-Length: " . filesize($filename));
header('Content-Type: video/flv');
header("Content-Disposition: attachment; filename= $fichero");
readfile($filename);