emerge -av mplayer
 
These are the packages that would be merged, in order:
 
Calculating dependencies... done!
[ebuild   R   ] media-video/mplayer-1.0_rc1-r2  USE="3dnow 3dnowext X aac alsa dts dvb dvd encode gtk iconv ipv6 jack joystick jpeg mad (mmx) mmxext opengl png sdl speex (sse) (sse2) truetype unicode v4l v4l2 vorbis xinerama xv xvmc (-3dfx) -aalib (-altivec) -amr -arts -bidi -bindist -bl -cdparanoia -cpudetection -custom-cflags -debug -dga -directfb -doc -dv -dvdread -enca -esd -fbcon -ggi -gif -libcaca -lirc -live -livecd -lzo -matrox -musepack -nas -openal -oss -real -rtc -samba (-svga) -tga -theora (-win32codecs) -x264 -xanim -xvid" LINGUAS="en es -bg -cs -da -de -el -fr -hu -ja -ko -mk -nl -no -pl -pt_BR -ro -ru -sk -tr -uk -zh_CN -zh_TW" 
 
 
 
mplayer
MPlayer 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ (Family: 15, Model: 43, Stepping: 1)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compilado para CPU x86 con extensiones: MMX MMX2 3DNow 3DNowEx SSE SSE2