[MPlayer-users] Mplayer usage as digital signage

Marcin Gałczyński marcin at galczynski.pl
Sat Sep 14 17:14:50 CEST 2013


I use Mplayer in digital signage application. The main idea is that 
there is seamless commercial video playback (seamless = no black screens 
and no dis- or badly joined movies). I have a good working solution now. 
MLT is used to generate the big "tape" with many flat screen and video 
commercial, using some transitions and ensuring it loops nicely 
altogether and can be largely automated.

To start mplayer a command is used:

# $NEWESTMOVIE has the movie name
/bin/mplayer -quiet -fixed-vo -nolirc -nomouseinput -nosub -noautosub 
-osd-duration 0 -osdlevel 0 -slave -nosound -noconsolecontrols -input 
file=/tmp/mpfc1 $NEWESTMOVIE -loop 0 >../logs/movieplayer.log.currlast 

Then while it's looping, in background MLT generates new movie (new 
order of commercials, new transitions etc). This is the code used to 
seamlessly switch to the next movie.

# what is the next movie
NEWESTMOVIE=`ls -t /home/rsu/movie/*vid | head -n 1`
# stop current loop
/bin/echo "loop -1 1" >/tmp/mpfc1
# add new file
/bin/echo "loadfile $NEWESTMOVIE 1" >/tmp/mpfc1
# wait for next movie to be started
while [ $REC -eq 0 ]
   REC=`lsof -p $(pidof mplayer) | grep $NEWESTMOVIE | wc -l`
   sleep 1
# set the infinite loop for new (now current) movie file
/bin/echo "loop 0 1" >/tmp/mpfc1

Getting the latter done felt like hacking, including getting thru player 
code to understand the loop controls, and also using lsof to get current 
file is not staight either.

This solution has one good thing - it really works well and does what is 
requested. If you generate constantly new movies and need to play them 
one after another, while looping the last one until next one is ready - 
this works like a charm.

Now I do have also some questions
- will this keep on working - maybe there are upcoming developments that 
would be breaking (fixing? ;-) the looping control and slave mode?
- is this the only way to make this work - or being less general - is 
there a way to avoid waiting for the movie to start playing before 
setting the infinite loop (without the wait it did not really work)?
- (not this list maybe) would code contributions in the area of slave 
control be useful? i would be happy to contribute :)


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