In order to enable support for mp4v2 video playback with vlc, media-libs/libmp4v2 is needed. Currently there is no option to enable this support for vlc with a use flag. [21:32:29][Wed Feb 29] [kat - ~] emerge --info vlc Portage 2.1.10.49 (default/linux/amd64/10.0, gcc-4.6.2, glibc-2.14.1-r2, 3.2.6-gentoo x86_64) ================================================================= System Settings ================================================================= System uname: Linux-3.2.6-gentoo-x86_64-Intel-R-_Core-TM-_i3_CPU_M_370_@_2.40GHz-with-gentoo-2.1 Timestamp of tree: Thu, 01 Mar 2012 02:30:01 +0000 app-shells/bash: 4.2_p20 dev-lang/python: 2.7.2-r3, 3.2.2 dev-util/cmake: 2.8.7-r3 dev-util/pkgconfig: 0.26 sys-apps/baselayout: 2.1 sys-apps/openrc: 0.9.9.2 sys-apps/sandbox: 2.5 sys-devel/autoconf: 2.13, 2.68 sys-devel/automake: 1.11.3 sys-devel/binutils: 2.22-r1 sys-devel/gcc: 4.6.2 sys-devel/gcc-config: 1.5.1 sys-devel/libtool: 2.4.2 sys-devel/make: 3.82-r3 sys-kernel/linux-headers: 3.2-r1 (virtual/os-headers) sys-libs/glibc: 2.14.1-r2 Repositories: gentoo anarchy mozilla ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="* -@EULA AdobeFlash-10.3" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -march=native -pipe -Wimplicit-function-declaration" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -march=native -pipe -Wenum-compare" DISTDIR="/usr/portage/distfiles" EMERGE_DEFAULT_OPTS="--with-bdeps=y --quiet-build=y" FEATURES="assume-digests binpkg-logs distlocks ebuild-locks fixlafiles news parallel-fetch protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox" FFLAGS="" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="en_US.UTF-8" LC_ALL="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed -Wl,-O1 -Wl,--hash-style=gnu -Wl,--sort-common" MAKEOPTS="-j5 -s --no-print-directory" PKGDIR="/usr/portage/packages" PORTAGE_COMPRESS="xz" PORTAGE_COMPRESS_FLAGS="-z -9 -f -S .xz" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp/tmpfs" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/home/gentoo /home/mozilla" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="X a52 aac alsa amd64 apng audit berkdb bidi bluetooth bzip2 cairo cdda cdio cli consolekit corefonts cracklib crypt cxx dbus djvu dri dts dvd encode ffmpeg flac fortran freetype gdbm gpm gtk gtk3 httpd iconv jpeg libffi libssh2 live lzma mad matroska mmx modules mp3 mpeg mudflap multilib ncurses nptl nptlonly nsplugin nss ogg oggvorbis opengl openmp pam pam_ssh pango pcre png policykit pppd python3 readline sdl session spell sqlite sse sse2 sse3 ssl ssse3 stream svg sysfs syslog tcpd theora thunar tiff truetype udev unicode usb vcd vlm vorbis vpx x264 xinerama xorg xv xvid zlib" ALSA_CARDS="hda-intel" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" CALLIGRA_FEATURES="kexi words flow plan stage tables krita karbon braindump" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" GRUB_PLATFORMS="pc" INPUT_DEVICES="evdev synaptics" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" PHP_TARGETS="php5-3" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="intel" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, INSTALL_MASK, LINGUAS, PORTAGE_BUNZIP2_COMMAND, PORTAGE_RSYNC_EXTRA_OPTS ================================================================= Package Settings ================================================================= media-video/vlc-2.0.0 was built with the following: USE="X a52 aac alsa avcodec avformat bidi cdda dbus dts dvbpsi dvd encode ffmpeg flac gcrypt gnutls httpd live matroska mmx mp3 mpeg (multilib) ncurses ogg opengl png postproc qt4 sdl skins sqlite sse svg swscale theora truetype udev vlm vorbis x264 xcb xv -aalib (-altivec) -atmo (-audioqueue) -avahi -bluray -cddb -dc1394 -debug -dirac (-direct2d) -directfb (-directx) (-dshow) -dvb (-dxva2) -egl -fbosd -fluidsynth -fontconfig -gme -gnome -growl -ieee1394 (-ios-vout) -jack -kate -kde -libass -libcaca -libnotify -libproxy -libsamplerate -libtar -libtiger -linsys -lirc -lua (-macosx) (-macosx-audio) (-macosx-dialog-provider) (-macosx-eyetv) (-macosx-qtkit) (-macosx-quartztext) (-macosx-vout) (-media-library) -modplug -mtp -musepack (-neon) -omxil -optimisememory -oss -portaudio -projectm -pulseaudio -pvr -rtsp -run-as-root -samba -schroedinger -sdl-image -shine -shout -sid -speex -switcher -taglib -twolame -upnp -v4l -vaapi -vcdx (-waveout) (-win32codecs) (-wingdi) -wma-fixed -xml -xosd -zvbi"
hmm, vlc has its own mp4 demuxer, what does mp4v2 would improve ? anyway, vlc code has no reference to libmp4v2, so what you should probably do it contact upstream and/or write a vlc module for libmp4v2, its not something gentoo as a distribution can improve but rather developping vlc, which is upstream's role.
