mplayer是一款非常强大的播放器，至少在linux中，大部分的视频播放都可以由它来完成。我也一直在使用mplayer，用着很不错。
一般我都是在命令行直接调用mplayer来播放电影。但是在使用的时候，感觉有一点很不爽：如果想快进的话，只能去按方向键。一般情况下按方向键的话，手就要离开键盘了。
反正感觉很不爽。而我现在也会一些vi的操作，对jk键非常喜欢。所以就想，能不能用jk键实现快进和快退呢？
然后我就从网上搜索相关内容，这种关于mplayer自定义按键的帖子很少。还好，从一些帖子中了解到mplayer的按键控制是放在文件/etc/mplayer/input.conf文件中的：
RIGHT seek +10
LEFT seek -10
DOWN seek -60
UP seek +60
PGUP seek 600
PGDWN seek -600
m mute
# switch_audio # switch audio streams
+ audio_delay 0.100
= audio_delay 0.100
- audio_delay -0.100
[ speed_mult 0.9091 # scale playback speed
] speed_mult 1.1
{ speed_mult 0.5
} speed_mult 2.0
BS speed_set 1.0 # reset speed to normal
q quit
ESC quit
ENTER pt_step 1 1 # skip to next file
p pause
. frame_step # advance one frame and pause
SPACE pause
HOME pt_up_step 1
END pt_up_step -1
> pt_step 1 # skip to next file
< pt_step -1 # previous
INS alt_src_step 1
DEL alt_src_step -1
o osd
I osd_show_property_text "${filename}" # display filename in osd
P osd_show_progression
z sub_delay -0.1 # subtract 100 ms delay from subs
x sub_delay +0.1 # add
9 volume -1
/ volume -1
0 volume 1
* volume 1
1 contrast -1
2 contrast 1
3 brightness -1
4 brightness 1
5 hue -1
6 hue 1
7 saturation -1
8 saturation 1
( balance -0.1 # adjust audio balance in favor of left
) balance +0.1 # right
d frame_drop
D step_property deinterlace # toggle deinterlacer, requires -vf yadif or kerndeint
r sub_pos -1 # move subtitles up
t sub_pos +1 # down
#? sub_step +1 # immediately display next subtitle
#? sub_step -1 # previous
#? sub_scale +0.1 # increase subtitle font size
#? sub_scale -0.1 # decrease subtitle font size
f vo_fullscreen
T vo_ontop # toggle video window ontop of other windows
w panscan -0.1 # zoom out with -panscan 0 -fs
e panscan +0.1 # in
s screenshot # take a png screenshot with -vf screenshot
# S will take a png screenshot of every frame
h tv_step_channel 1
l tv_step_channel -1
n tv_step_norm
b tv_step_chanlist
LEFT seek -10
DOWN seek -60
UP seek +60
PGUP seek 600
PGDWN seek -600
m mute
# switch_audio # switch audio streams
+ audio_delay 0.100
= audio_delay 0.100
- audio_delay -0.100
[ speed_mult 0.9091 # scale playback speed
] speed_mult 1.1
{ speed_mult 0.5
} speed_mult 2.0
BS speed_set 1.0 # reset speed to normal
q quit
ESC quit
ENTER pt_step 1 1 # skip to next file
p pause
. frame_step # advance one frame and pause
SPACE pause
HOME pt_up_step 1
END pt_up_step -1
> pt_step 1 # skip to next file
< pt_step -1 # previous
INS alt_src_step 1
DEL alt_src_step -1
o osd
I osd_show_property_text "${filename}" # display filename in osd
P osd_show_progression
z sub_delay -0.1 # subtract 100 ms delay from subs
x sub_delay +0.1 # add
9 volume -1
/ volume -1
0 volume 1
* volume 1
1 contrast -1
2 contrast 1
3 brightness -1
4 brightness 1
5 hue -1
6 hue 1
7 saturation -1
8 saturation 1
( balance -0.1 # adjust audio balance in favor of left
) balance +0.1 # right
d frame_drop
D step_property deinterlace # toggle deinterlacer, requires -vf yadif or kerndeint
r sub_pos -1 # move subtitles up
t sub_pos +1 # down
#? sub_step +1 # immediately display next subtitle
#? sub_step -1 # previous
#? sub_scale +0.1 # increase subtitle font size
#? sub_scale -0.1 # decrease subtitle font size
f vo_fullscreen
T vo_ontop # toggle video window ontop of other windows
w panscan -0.1 # zoom out with -panscan 0 -fs
e panscan +0.1 # in
s screenshot # take a png screenshot with -vf screenshot
# S will take a png screenshot of every frame
h tv_step_channel 1
l tv_step_channel -1
n tv_step_norm
b tv_step_chanlist
以上是input.conf中的部分内容。从中可以看到很多我们常用的按键都是在这儿定义的。
但是怎么修改按键呢？一种简单的方法就是直接修改这个文件。这是可以的，这个文件中开始的注释部分也提到了：可以通过修改该文件来配置mplayer的按键。
但是我不想修改mplayer的这个文件。在linux下的软件都一个特点，一般都有一个全局的配置文件(一般在etc目录下)，同时用户可以在自己的home目录中编写自己的配置文件来满足自己的要求，如果用户配置和全局配置有冲突的话，自己的配置文件会覆盖全局配置文件中相应的配置，vim、bash就是这个特点。所以，我就想mplayer是不是也是这样呢？管他呢，试试吧。然后我就把input.conf文件复制到mplayer的配置目录～/.mplayer/中。然后，对input.conf进行简单修改，主要是用jk键来代替快退和块进的功能，即：
k seek +10
j seek -10
# switch_audio # switch audio streams
#I osd_show_property_text "${filename}" # display filename in osd
#P osd_show_progression
#f vo_fullscreen
#T vo_ontop # toggle video window ontop of other windows
#s screenshot # take a png screenshot with -vf screenshot
# S will take a png screenshot of every frame
j seek -10
# switch_audio # switch audio streams
#I osd_show_property_text "${filename}" # display filename in osd
#P osd_show_progression
#f vo_fullscreen
#T vo_ontop # toggle video window ontop of other windows
#s screenshot # take a png screenshot with -vf screenshot
# S will take a png screenshot of every frame
保存之后，打开mplayer测试，果然可以了。
现在只是简单的配置，以后想到其他的用法的时候可以不断修改这个文件。