Русские субтитры mplayer

Система с юникодом, mplayer собран со след USE -
> equery u mplayer

[ Searching for packages matching mplayer... ]
[ Colour Code : set unset ]
[ Legend : Left column  (U) - USE flags from make.conf              ]
[        : Right column (I) - USE flags packages was installed with ]
[ Found these USE variables for media-video/mplayer-1.0.20070427 ]
 U I
 - - 3dnow               : Adds support for 3dnow multimedia processor instructions
 - - 3dnowext            : Enables 3dnow extensions in mplayer
 + + X                   : Adds support for X11
 + + a52                 : Enables support for decoding ATSC A/52 streams used in DVD
 + + aac                 : Enables support for MPEG-4 AAC Audio
 + + aalib               : Adds support for media-libs/aalib (ASCII-Graphics Library)
 + + alsa                : Adds support for media-libs/alsa-lib (Advanced Linux Sound Architecture)
 - - altivec             : Adds support for optimizations for G4 and G5/ppc970 processors
 - - amr                 : Enables Adaptive Multi-Rate Audio support
 + + arts                : Adds support for aRts: the KDE sound daemon
 + + bidi                : Enables bidirectional language support
 - - bindist             : Flag to enable or disable options for prebuilt (GRP)  packages (eg. due to licensing issues)
 + + bl                  : Enables Blinkenlights support in mplayer
 - - cddb                : Access cddb servers to retrieve and submit information about compact disks
 - - cdparanoia          : Enables cdparanoia (audio CD ripper) support
 - - cpudetection        : Enables runtime cpudetection
 - - custom-cflags       : Enables custom cflags (not supported)
 - - debug               : Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see http://www.gentoo.org/proj/en/qa/backtraces.xml .
 + + dga                 : Adds DGA Support (Xfree86) (DGA=Direct Graphic Access)
 + + directfb            : Adds support for DirectFB layer (library for FB devices)
 - - doc                 : Adds extra documentation (API, Javadoc, etc)
 + + dts                 : Enables libdts (DTS Coherent Acoustics decoder) support
 + + dv                  : Enables support for a codec used by many camcorders
 + + dvb                 : Adds support for DVB (Digital Video Broadcasting)
 + + dvd                 : Adds support for DVDs
 - - dvdnav              : DVD menu navigation support (not supported)
 + + dvdread             : Enables usage of Ogle's libdvdread for DVD playback
 + + enca                : Enables support for charset discovery and conversion
 + + encode              : Adds support for encoding of audio or video files
 + + esd                 : Adds support for media-sound/esound (Enlightened Sound Daemon)
 + + fbcon               : Adds framebuffer support for the console, via the kernel
 + + ftp                 : Adds FTP (File Transfer Protocol) support
 + + ggi                 : Adds support for media-libs/libggi (non-X video api/drivers)
 + + gif                 : Adds GIF image support
 + + gtk                 : Adds support for x11-libs/gtk+ (The GIMP Toolkit)
 + + iconv               : Enable support for the iconv character set conversion library
 - - ipv6                : Adds support for IP version 6
 - - ivtv                : Enable IVTV TV-Out video output
 + + jack                : Adds support for the JACK Audio Connection Kit
 - - joystick            : Add support for joysticks in all packages
 + + jpeg                : Adds JPEG image support
 + + libcaca             : Add support for colored ASCII-art graphics
 - - lirc                : Adds support for lirc (Linux's Infra-Red Remote Control)
 + + live                : Enables live.com streaming media support
 - - livecd              : !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used during livecd building.
 + + lzo                 : Enables support for lzo compression
 + + mad                 : Adds support for mad (high-quality mp3 decoder library and cli frontend)
 + + md5sum              : Enables md5sum video output
 + + mmx                 : Adds support for optimizations for Pentium MMX and Athlon class processors
 + + mmxext              : Enables mmx2 support
 + + mp2                 : Enables support for twolame, an MP2 audio library
 + + mp3                 : Add support for reading mp3 files
 + + musepack            : Enable support for the musepack audio codec
 + + nas                 : Adds support for network audio sound
 + + openal              : Adds support for the Open Audio Library
 + + opengl              : Adds support for OpenGL (3D graphics)
 + + oss                 : Adds support for OSS (Open Sound System)
 + + png                 : Adds support for libpng (PNG images)
 + + pnm                 : Add PNM video output option, to create PPM/PGM/PGMYUV images
 + + quicktime           : Adds support for OpenQuickTime
 + + radio               : Enable V4L2 radio interface and support
 + + rar                 : Enable Unique RAR File Library
 + + real                : Adds real video support
 + + rtc                 : Enables usage of the linux real time clock.  The alternative is software emulation of rtc
 + + samba               : Adds support for SAMBA (Windows File and Printer sharing)
 + + sdl                 : Adds support for Simple Direct Layer (media library)
 + + speex               : Adds support for the speex audio codec
 + + srt                 : Internal SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support
 + + sse                 : fast floating point optimization for PentiumIII+ class chips
 + + sse2                : faster floating point optimization for SSE2 capable chips
 + + svga                : Adds support for SVGAlib (graphics library)
 - - tga                 : Enables Targa video output
 + + theora              : Adds support for the Theora Video Compression Codec
 - - tivo                : Enables TiVo vstream client support
 + + truetype            : Adds support for FreeType and/or FreeType2 fonts
 + + unicode             : Adds support for Unicode
 + + v4l                 : Enables video4linux support
 + + v4l2                : Enables video4linux2 support
 - - video_cards_mga     : <unknown>
 - - video_cards_s3virge : <unknown>
 - - video_cards_tdfx    : <unknown>
 - - video_cards_vesa    : <unknown>
 - - vidix               : Support for vidix video output
 + + vorbis              : Adds support for the OggVorbis audio codec
 + + win32codecs         : use win32codecs package for dll avi decoding support (wmv and what not)
 + + x264                : Enable h264 encoding using x264
 + + xanim               : Enables support for xanim based codecs
 + + xinerama            : Add support for the xinerama X11 extension, which allows you to stretch your display across multiple monitors
 + + xv                  : Adds in optional support for the Xvideo extension (an X API for video playback)
 + + xvid                : Adds support for xvid.org's open-source mpeg-4 codec
 + + xvmc                : Enables X-Video Motion Compensation support
 - - zoran               : Enables ZR360[56]7/ZR36060 video output

Конфиг mplayer'a:
> cat ~/.mplayer/config | grep -vr "^#" | grep -vr "^[[:space:]]$"

autosync=100
font='Comic Sans MS'
ass=yes
fontconfig=yes
framedrop=no
double=yes
ffactor=10
quiet=yes
subfont-autoscale=1
subfont-blur=5
subfont-outline=2
subfont-text-scale=6
subpos=86
sub-bg-alpha=255
fixed-vo=yes
subcp=cp1251

Т.е. mplayer собран и работает с поддержкой ass, за это отвечает USE флаг srt, кстати всем советую включить эту опцию, равно как и truetype флаг для поддержки ttf шрифтов, определенно приятнее смотреть видео с ssa/ass субтитрами использущими разные шрифты, цвета и свободное позиционирование. Шрифты берет из fontconfig'а, по умолчанию используется шрифт 'Comic Sans MS', остальное не столь важно. Альфу можно выключить - это прозрачность...
Далее, проблем с русскими субтитрами не наблюдалось вообще, разве что когда по умолчанию используется шрифт в котором нет кирилической таблицы (что вероятно имеет место быть у вас, судя по значкам "__" вместо русских букв). Иногда при просмотре с субтитрами в utf-8 приходится в ручную менять кодировку параметром командной строки -subcp utf8.