Something

g++ -shared -Wl,-soname,libmythavcodec-0.20.so.0 -o libmythavcodec-0.20.so.0.20.0 bitstream.o utils.o allcodecs.o mpegvideo.o jrevdct.o jfdctfst.o jfdctint.o mpegaudio.o ac3enc.o mjpeg.o audresample.o resample2.o dsputil.o motion_est.o imgconvert.o imgresample.o mpeg12.o mpegaudiodec.o pcm.o simple_idct.o ratecontrol.o adpcm.o eval.o error_resilience.o fft.o mdct.o raw.o golomb.o cabac.o dpcm.o adx.o faandct.o parser.o g726.o vp3dsp.o bitstream_filter.o h264idct.o rangecoder.o pnm.o h263.o msmpeg4.o h263dec.o dvdsub.o dvbsub.o dvbsubdec.o dvdsubenc.o opt.o lzo.o myth_utils.o audioconvert.o aasc.o alac.o asv1.o avs.o cavs.o cavsdsp.o cinepak.o cook.o cljr.o cyuv.o dv.o 8bps.o ffv1.o flac.o flacenc.o flashsv.o flicvideo.o 4xm.o fraps.o h261.o h264.o huffyuv.o idcinvideo.o indeo2.o indeo3.o interplayvideo.o kmvc.o lcl.o loco.o mace.o msrle.o msvideo1.o png.o qdm2.o qdrw.o qpeg.o qtrle.o ra144.o ra288.o roqvideo.o rpza.o rv10.o shorten.o smacker.o smc.o snow.o sonic.o svq1.o truemotion1.o truemotion2.o truespeech.o tta.o tscc.o cscd.o nuv.o rtjpeg.o ulti.o vc1.o vc1dsp.o vcr1.o vmdav.o vorbis.o vp3.o vqavideo.o wmadec.o wnv1.o ws-snd1.o xan.o xl.o bmp.o mmvideo.o zmbv.o a52dec.o bit_allocate.o a52_bitstream.o downmix.o imdct.o parse.o crc.o resample.o dtsdec.o fdct_mmx.o cputest.o dsputil_mmx.o mpegvideo_mmx.o idct_mmx.o motion_est_mmx.o simple_idct_mmx.o fft_sse.o vp3dsp_mmx.o vp3dsp_sse2.o idct_mmx_xvid.o fft_3dn.o fft_3dn2.o cavsdsp_mmx.o   -L/usr/qt/3/lib -L/usr/X11R6/lib -lz -L../libavutil -lmythavutil-0.20 -ldts -lqt-mt -lXext -lX11 -lm -lpthread 
/usr/lib/gcc/i686-pc-linux-gnu/3.4.4/../../../../i686-pc-linux-gnu/bin/ld: cannot find -lXext
collect2: ld returned 1 exit status
make[2]: *** [libmythavcodec-0.20.so.0.20.0] Error 1
make[2]: Leaving directory `/var/tmp/portage/mythtv-0.20_p11444/work/mythtv-0.20/libs/libavcodec'
make[1]: *** [sub-libavcodec] Error 2
make[1]: Leaving directory `/var/tmp/portage/mythtv-0.20_p11444/work/mythtv-0.20/libs'
make: *** [sub-libs] Error 2

!!! ERROR: media-tv/mythtv-0.20_p11444 failed.
Call stack:
  ebuild.sh, line 1546:   Called dyn_compile
  ebuild.sh, line 937:   Called src_compile
  mythtv-0.20_p11444.ebuild, line 199:   Called die

!!! emake failed
!!! If you need support, post the topmost build error, and the call stack if relevant.



mail lib # emerge info
*** Deprecated use of action 'info', use '--info' instead
Portage 2.1.1-r1 (default-linux/amd64/2006.1/desktop, gcc-3.4.4, glibc-2.3.5-r3, 2.6.12-gentoo-r9 i686)
=================================================================
System uname: 2.6.12-gentoo-r9 i686 AMD Sempron(tm) Processor 3000+
Gentoo Base System version 1.12.0_pre11
Last Sync: Tue, 17 Oct 2006 00:00:01 +0000
distcc 2.18.3 i686-pc-linux-gnu (protocols 1 and 2) (default port 3632) [disabled]
app-admin/eselect-compiler: [Not Present]
dev-java/java-config: 1.2.11-r1
dev-lang/python:     2.3.5, 2.4.2
dev-python/pycrypto: 2.0.1-r5
dev-util/ccache:     [Not Present]
dev-util/confcache:  [Not Present]
sys-apps/sandbox:    1.2.12
sys-devel/autoconf:  2.13, 2.59-r7
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils:  2.17
sys-devel/gcc-config: 1.3.12-r4
sys-devel/libtool:   1.5.20-r1
virtual/os-headers:  2.6.11-r3
ACCEPT_KEYWORDS="amd64"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-march=athlon-xp -O3 -pipe -fomit-frame-pointer"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/lib/X11/xkb /usr/share/config"
CONFIG_PROTECT_MASK="/etc/env.d /etc/gconf /etc/revdep-rebuild /etc/terminfo /etc/texmf/web2c"
CXXFLAGS="-march=athlon-xp -O3 -pipe -fomit-frame-pointer"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig distlocks metadata-transfer sandbox sfperms strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude='/distfiles' --exclude='/local' --exclude='/packages'"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="amd64 X alsa arts berkdb bitmap-fonts cairo cdr cli crypt cups dbus dlloader dri dvd dvdr eds elibc_glibc emboss encode esd fam firefox fortran gdbm gif gnome gpm gstreamer gtk gtk2 hal input_devices_evdev input_devices_keyboard input_devices_mouse ipv6 isdnlog jpeg kde kernel_linux ldap libg++ mad mikmod mp3 mpeg mysql ncurses nls nptl nptlonly ogg opengl oss pam pcre perl png ppds pppd python qt3 qt4 quicktime readline reflection sdl session spell spl ssl tcpd truetype truetype-fonts type1-fonts udev unicode userland_GNU vhosts video_cards_apm video_cards_ark video_cards_ati video_cards_chips video_cards_cirrus video_cards_cyrix video_cards_dummy video_cards_fbdev video_cards_glint video_cards_i128 video_cards_i810 video_cards_mga video_cards_neomagic video_cards_nv video_cards_rendition video_cards_s3 video_cards_s3virge video_cards_savage video_cards_siliconmotion video_cards_sis video_cards_sisusb video_cards_tdfx video_cards_tga video_cards_trident video_cards_tseng video_cards_v4l video_cards_vesa video_cards_vga video_cards_via video_cards_vmware video_cards_voodoo vorbis x86 xml xorg xv zlib"
Unset:  CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS, MAKEOPTS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY