I'm using Slackware.
I thought of installing Mplayer.
After extracting and entering inside the directory I did:
./configure
I didn't noticed the text scrolling.
After that entered make
The text were scrolling and at the last there were some error. Like this:

vo_ivtv.c: In function 'ivtv_reset':
vo_ivtv.c:79: error: storage size of 'sd' isn't known
vo_ivtv.c:80: error: storage size of 'sd1' isn't known
vo_ivtv.c:84: error: 'IVTV_STOP_FL_HIDE_FRAME' undeclared (first use in this function)
vo_ivtv.c:84: error: (Each undeclared identifier is reported only once
vo_ivtv.c:84: error: for each function it appears in.)
vo_ivtv.c:87: error: 'IVTV_IOC_STOP_DECODE' undeclared (first use in this function)
vo_ivtv.c:97: error: 'IVTV_IOC_START_DECODE' undeclared (first use in this function)
vo_ivtv.c:80: warning: unused variable 'sd1'
vo_ivtv.c:79: warning: unused variable 'sd'
make[1]: *** [vo_ivtv.o] Error 1
make[1]: Leaving directory `/home/soul/Backup/Audio And Video Tools/MPlayer-1.0rc2/libvo'
make: *** [libvo/libvo.a] Error 2


Now can't I install MPlayer

You should use the SlackBuilds for MPlayer and its codecs:
http://slackbuilds.org/repository/12.2/multimedia/
First of all, get sbopkg, it makes the installation of SlackBuilds easier:
http://www.sbopkg.org/