Mplayer问题，急急。。。

我在终端输入Mplayer出现以下代码，不知道何意，请高手指点

MPlayer SVN-r31027-4.4.2 (C) 2000-2010 MPlayer Team
Usage: mplayer [options] [url|path/]filename

Basic options: (complete list in the man page)
-vo select video output driver ('-vo help' for a list)
-ao select audio output driver ('-ao help' for a list)
vcd:// play (S)VCD (Super Video CD) track (raw device, no mount)
dvd:// play DVD title from device instead of plain file
-alang/-slang select DVD audio/subtitle language (by 2-char country code)
-ss seek to given (seconds or hh:mm:ss) position
-nosound do not play sound
-fs fullscreen playback (or -vm, -zoom, details in the man page)
-x -y set display resolution (for use with -vm or -zoom)
-sub specify subtitle file to use (also see -subfps, -subdelay)
-playlist specify playlist file
-vid x -aid y select video (x) and audio (y) stream to play
-fps x -srate y change video (x fps) and audio (y Hz) rate
-pp enable postprocessing filter (details in the man page)
-framedrop enable frame dropping (for slow machines)

Basic keys: (complete list in the man page, also check input.conf)
<- or -> seek backward/forward 10 seconds
down or up seek backward/forward 1 minute
pgdown or pgup seek backward/forward 10 minutes
step backward/forward in playlist
p or SPACE pause movie (press any key to continue)
q or ESC stop playing and quit program
+ or - adjust audio delay by +/- 0.1 second
o cycle OSD mode: none / seekbar / seekbar + timer
* or / increase or decrease PCM volume
x or z adjust subtitle delay by +/- 0.1 second
r or t adjust subtitle position up/down, also see -vf expand

* * * SEE THE MAN PAGE FOR DETAILS, FURTHER (ADVANCED) OPTIONS AND KEYS * * *