[求助]gentoo下的mplayer出现声画不同步

$ eix -e ffmpeg
[i] media-video/ffmpeg
 Available versions: 0.4.9_p20081014 (~)0.4.9_p20081219 [M]**9999 {X aac altivec amr bindist debug dirac doc encode gsm hardcoded-tables ieee1394 ipv6 mmx mmxext mp3 network schroedinger sdl speex ssse3 test theora threads v4l v4l2 vhook vorbis x264 xvid zlib}
 Installed versions: 0.4.9_p20081219(10时54分31秒 2008年12月20日)(X aac encode ipv6 mmx mmxext mp3 ssse3 x264 xvid zlib -altivec -amr -bindist -debug -dirac -doc -gsm -hardcoded-tables -ieee1394 -network -schroedinger -sdl -speex -test -theora -threads -v4l -v4l2 -vhook -vorbis)
 Homepage: http://ffmpeg.org/
 Description: Complete solution to record, convert and stream audio and video. Includes libavcodec. live svn

aptitude show ffmpeg
软件包： ffmpeg
状态: 已安装
自动安装: 否
版本号： 3:0.svn20080206-12ubuntu3
优先级： 可选
部分： graphics
维护者： Reinhard Tartler <[email protected]>
未压缩尺寸： 885k
依赖于: libavcodec51 (>= 3:0.svn20080206-8) | libavcodec-unstripped-51 (>= 3:0.svn20080206-8), libavdevice52 (>= 3:0.svn20080206-8) |
 libavdevice-unstripped-52 (>= 3:0.svn20080206-8), libavformat52 (>= 3:0.svn20080206-8) | libavformat-unstripped-52 (>= 3:0.svn20080206-8),
 libavutil49 (>= 3:0.svn20080206-8) | libavutil-unstripped-49 (>= 3:0.svn20080206-8), libc6 (>= 2.7), libfreetype6 (>= 2.3.5), libimlib2,
 libsdl1.2debian (>= 1.2.10-1), libswscale0 (>= 3:0.svn20080206-8) | libswscale-unstripped-0 (>= 3:0.svn20080206-8)
描述： multimedia player, server and encoder
 This package contains the ffplay multimedia player, the ffserver streaming server and the ffmpeg audio and video encoder. They support most existing
 file formats (AVI, MPEG, OGG, Matroska, ASF...) and encoding formats (MPEG, DivX, MPEG4, AC3, DV...).
Homepage: http://ffmpeg.mplayerhq.hu/

# Write your default config options here!
vo=x11
ao=alsa


font=/home/lily/.fonts/VeraSansYuanTi-Regular.ttf
subcp=cp936
subfont-autoscale=0
subfont-osd-scale=20
subfont-text-scale=40

zoom=yes