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Soundstation: 5 - Watch movies


5a - Resolution
Music is working. Nice! But in the end I have a whole PC sitting there just ripping and playing music - why not making it do more stuff? And what? Why not playing movies? So, the first problem I came across is the resolution.
I have a 16:9 TV, which is a ~1.7 ratio. The native resolution of my touchscreen is 800x600, which is a ~1.33 ratio. This means that if I start up the desktop with a 800x600 resolution, the image on screen will be distorted.
I tried to use the MPlayer settings to change the aspect ratio of the movies, but that comes at a cost of ~90% CPU usage on my 800Mhz machine while playing movies, as this is not hardware accellerated. I therefore had to change the resolution, but to which one? Well, one of the standard VGA resolutions that has an aspect ratio near to 1.7 is 1280x768, which gives a ratio of ~1.66.
Ok, I now know I somehow have to change res when I want to play videos. How?
What I did was:

  • When you login into your Linux, the system automatically searches a file called .profile in your home directory (at least if you're using the bash shell). I therefore created a .profile containing the following code: 
echo "This is your .profile script"
tty
TERMINAL=$(tty)

if [ "$TERMINAL" = "/dev/tty1" ]
then
        echo "This is the main terminal, so I am starting up X"
        /home/shared/scripts/startx_custom
else
        echo "This is a secondary terminal, so I won't start up X"
fi
What the script does is to fire up the script /home/shared/scripts/startx_custom if the terminal which is being to login is the main one (this is the case if you implemented the automatic login). If you connect though SSH or some other terminal, nothing will happen. You will see below that the script startx_custom contains an infinite loop which will allow you to switch resolution.
Ok, I admit that this is probably the loser's way of doing it, but in the end it works reliably and I anyway didn't find any other way.
  • Let's have a look at the startx_custom script: 
STESCRIPTS="/home/shared/scripts"
export STESCRIPTS

for ((a=1;a<2;))
do
        sleep 2

        #Get the information about what has to be done
        #0=Shutdown
        #1=Start music mode - use xorg.conf.master.pc
        #2=Start video mode - use xorg.conf.master.tv
        ACTION=$(cat $STESCRIPTS/startx_nextaction)

        #For cases 1 and 2, copy the xorg.conf and enlightenment files and fire up enlightenment.
        #For case 0, exit the loop and shut down the machine.
        #When the machine is booted, the value 1 will automatically be assigned by an init script.
        case "$ACTION" in
                0)
                        #Shutdown
                        #echo exiting script
                        a=3
                        ;;
                1)
                        cp /home/masterfiles/enlightenment.master.pc /etc/X11/Sessions/enlightenment
                        $STESCRIPTS/touchscreen/tchscreen_replaceevent
                        echo Y > /sys/module/usbtouchscreen/parameters/swap_xy
                        echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
                        startx
                        #echo starting into pc mode
                        #sleep 10
                        ;;

                2)
                        cp /home/masterfiles/enlightenment.master.tv /etc/X11/Sessions/enlightenment
                        cp /home/masterfiles/xorg.conf.master.tv /etc/X11/xorg.conf
                        nxtvepg -daemonstop
                        killall nxtvepg
                        echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
                        startx
                        #echo starting into tv mode
                        #sleep 10
                        ;;

                *)
                        echo nothing >> /dev/null
                        ;;
        esac
done

shutdown -h now
#echo Shutting down the pc
You see that what I'm doing is to copy the xorg.conf file from the master location (a normal cp if I go to TV mode, as I don't need the touchscreen and I run the script tchscreen_replaceevent if I want to go to music mode, which replaces xorg.conf - see the previous sections for the contents of this script) and set the appropriate enlightenment file for the applications I want to start immediately. The two xorg.conf have a different resolution - the .pc runs with 800x600 and the .tv runs with 1280x768.
  • As with the above script the value in the temporary file is set to 0 when shutting down, I had to set a default value during boot in the file /etc/init.d/startx_prepare: 
#Used to make X start with the pc setup (for music)
start() {
        echo 1 > /home/shared/scripts/startx_nextaction
        }
stop() {
        echo ciao >> /dev/null
        }
  • What drives which mode is chosen? Well, the config file of the remote control ~/.lircrc sets the value... 
begin
        prog = irexec
        button = Videos
        config = /home/shared/scripts/x_switch2tv &
end
begin
        prog = irexec
        button = Music
        config = /home/shared/scripts/x_switch2pc &
end
...through the scripts x_switch2tv... 
#This command will return an error if Amarok is not running - it's ok.
dcop amarok MainApplication-Interface quit

#Set the next action of the script startx_custom to go into TV mode.
echo 2 > /home/shared/scripts/startx_nextaction

#Close the X desktop, so that the script startx_custom can continue its execution.
eesh exit
...or x_switch2pc: 
#This command will return an error if Amarok is not running - it's ok.
dcop amarok MainApplication-Interface quit

#Set the next action of the script startx_custom to go into PC mode.
echo 1 > /home/shared/scripts/startx_nextaction

#Close the X desktop, so that the script startx_custom can continue its execution.
eesh exit


5b - Movie application
Ok, now I press on the Video button of the remote control, the desktop shuts down and restarts with a resolution 1280x768 - I just need a program to act as a movie jukebox!
I knew MythTV, but that is more a TV recording app. I therefore chose freevo, which fits better.
The funny thing I noticed is, that when I was playing a movie using MPlayer through Freevo, I had 10% CPU overhead compared to directly run MPlayer as a standalone. I traced back the source and, apparently, Freevo forces MPlayer to do deinterlacing for any kind of video (I have an LCD TV, so I don't need this). Additionally I forced in the Freevo config file /etc/freeevo//etc/local_conf.py MPlayer to use xv as output driver. Here is the final section of the local_conf.py'' file... 

MPLAYER_ARGS_DEF = '-fs -vo xv -aspect 16:9 -cache 20000'

#OSD_STOP_WHEN_PLAYING = 1

#MPLAYER_VO_DEV_OPTS  = 'xv'
MPLAYER_NICE         = 0
MPLAYER_AO_DEV = 'alsa:device=spdif'
#STECUSTOM: modified in file /usr/lib/python2.4/site-packages/freevo/video/plugins/mplayer.py
#and commented 6 lines starting with if self.version >= 1 and item['deinterlace']:
#to avoid doing de/interlacing online.
...and here is the mplayer .py part I commented out: 
        if item.selected_audio != None:
            additional_args += [ '-aid', str(item.selected_audio) ]

#        if self.version >= 1 and item['deinterlace']:
#            additional_args += [ '-vf',  config.MPLAYER_VF_INTERLACED ]
#        elif item['deinterlace']:
#            additional_args += [ '-vop', config.MPLAYER_VF_INTERLACED ]
#        elif self.version >= 1:
#            additional_args += [ '-vf',  config.MPLAYER_VF_PROGRESSIVE ]

        mode = item.mimetype
        if not config.MPLAYER_ARGS.has_key(mode):
            mode = 'default'

2bcontinued...



Chapter 1 - Theory & hardware
Chapter 2 - Initial setup
Chapter 3 - Jukebox music setup
Chapter 4 - CPU throttling & Co.
Chapter 5 - Watch movies <= You are here
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