Mplayer - The multimedia dynamite I


What would you desire of a movie player in linux?

It should play any movie/video that I throw at it. No 
questions asked.Just play. It should allow seeking
and volume controls with the keyboard and mouse. It should
work with an Infrared remote controller and also play 
television from a capture card. It should play DVDs and VCDs
too.

The list goes on. It so turns out that mplayer can do all
of this and much much more.

It is also an award winning mature open source program that is still
actively in development. Perhaps one day in the near future 
support for DVD menus, color subtitles, picture in picture video,
MIDI, audio effects plugins like the ones in sox and xmms and so on 
will get added.

It is admirably stable for the job it does. However it does
crash under certain circumstances. Largely I have found it
crashing with certain video drivers. 

It is a mature application that has no parallel. Its companion 
video encoder program mencoder does a much better job than ffmpeg
in transcoding videos though it is a bit hard to use and learn.

Now let us take a glimpse of mplayer magic.

$ mplayer -af lavcresample=48000,hrtf -playlist http://shoutcast.com/playlist.pls

would play the stream url in playlist format after resampling to 48,000
Hz followed by the head related transfer function processing.

Type this on a terminal.

$ mplayer -dumpstream -dumpfile stream.aac -softvol -softvol-max 2000 -af lavcresample=48000,volnorm=2:0.15  -playlist 'http://www.shoutcast.com/sbin/shoutcast-playlist.pls?rn=577678&file=filename.pls' 

Now go to another terminal and type

$ mplayer stream.aac

What happens?

The first instance of mplayer dumps the network stream to a file and the
second plays it for you. Timeshifted Internet radio. Cool eh?

The other options on the command line are not too hard to decipher.

The -playlist option is to be used only with stream urls that have a
.pls extension or a simpler approach would be to try without a -playlist
option. If it does not work, then try with this option. You could also
download the stream url with wget and examine its contents. 

Talking of playlists, how about this?

$ find /home/girish/music -name "*mp3 -o -name "*ogg" > ~/playlist.txt

Now fire up mplayer with

$ mplayer -playlist ~/playlist.txt

$ mplayer -shuffle -playlist ~/playlist.txt

would shuffle the list and play songs in random order without repeating
songs.

But mplayer is a media player, so you could also add any mplayer
playable media file into the mix, videos, movies, television, radio and 
of course Internet streams.

In addition to this simple line based playlist format, mplayer also has
excellent support for ASX, M3U and other popular playlist formats.

I have already shown mplayer's ability for sophisticated audio
processing/filtering above.

$ mplayer -af help

will list you the available filters and the man page and html
documentation has thorough description of its usage.

The karaoke effect gets very interesting with certain songs. It is 
not perfect but voice can be attenuated a great deal with it.

It also has a 10 octave band graphic equalizer but there is no graphics.

You specify it on the command line.

$ mplayer -af extrastereo song.mp3

gives a live effect to playback.

$ mplayer song1.mp3 song2.ogg file.wav -loop 5

will play the third song five times.

In case you want the whole list to be repeated n times, type

$ mplayer { song1.mp3 song2.ogg file.wav } -loop n

for playing it n times.

You can also use -loop 0 to play something over and over again.

$ mplayer -frames 1500 video.avi

will exit after decoding 1500 frames.

Due to the design of video decoding and keyframes this is not accurate.

There are very many effect plugins especially for multichannel and 3d
audio.

If you desire some really advanced audio effects I request you to try
the sox swiss army knife. It is also another command line application
that excels in professional audio effects.

And you can specify multiple audio filters on the command line and
they are applied one after another in a chain fashion.

Figure 1: mplayer-filter-chaining.eps
Caption: mplayer audio/video filter chaining

What if you like a certain audio filter chain and you wish to save it
onto a file?

$ mplayer -ao pcm:file=filtered.wav -channels 4 -af lavcresample=48000,hrtf,pan=2:1:0:0:0:0:1:0:0:0:0:1:0:0:0:0:1 audio.ogg

This will save the output of filtering into the file filtered.wav
instead of playing it.

You should of course do this once you are satisfied with the right
filter chains and tweaks. Most filters have knobs that you can tweak to
your taste.

Now let us move on to something even more interesting.

There is a very rich input command processing subsystem in mplayer which
can be manipulated with the keyboard, mouse, joystick or LIRC remote
control.

$ mplayer -input keylist
$ mplayer -input cmdlist

These two commands come in handy to help you configure input keys to
your taste. Also read the slave.txt file that comes with mplayer
documention and check out the input.conf and menu.conf files that come
with the mplayer package.

mplayer can also accept input commands from a fifo file which comes handy 
when it is reading the media from the standard input. This way you 
have the best of both worlds.

$ mkfifo /tmp/fifo
$ cat playlist.txt | mplayer -input file:/tmp/fifo -cache 8192 -playlist -

Now you can increase the volume with 

$ echo 'mute' > /tmp/fifo

will mute and executing it again with unmute the audio.

You can use the mouse for the usual seek operations. The mouse wheel is
configured by default to seek files in both directions.

mplayer's ability to accept media files and playlists from standard 
input has very interesting applications for specialized needs.

Apropos of input methods, mplayer has excellent support for on
screen display or OSD. I normally use only the superb scalable
TTF fonts.

$ mplayer -osdlevel 3 -font /home/girish/.ttffonts/comicbd.ttf video.avi

will display a timer on the top. Check out the screenshot.

Figure: mplayer-osd-timeline-display.png
Caption: mplayer with basic OSD support

But it can do much more.

You can have a custom menu that can be browsed using the keyboard
all using the OSD facility. It even has a console where you can 
enter mplayer slave commands.

Figure: mplayer-osd.png
Figure: mplayer-osd-console.png
Figure: mplayer-osd-properties.png
Caption: mplayer with OSD

As you can see, the OSD fonts being scalable do not break with the
video scale filter.

I love big anti aliased scalable fonts like this. You could also
configure the fonts to be as small as you prefer. There are several
knobs for them.

Here is my ~/.mplayer/config file.


# Write your default config options here!
# Use Matrox driver by default.
vo=sdl
font=/home/girish/.ttffonts/comicbd.ttf
vf=hue,eq,screenshot
#menu-startup=yes
menu=yes
subfont-autoscale=3
subfont-osd-scale=8
subfont-text-scale=8
subpos=50
spuaa=4
osdlevel=3
# I love doing headstand (Sirsasana) while watching videos.
#flip=yes
# Decode/encode multiple files from PNG,
# start with mf://filemask
mf=type=png:fps=25
# Eerie negative images are cool.
#vf=eq2=1.0:-0.8

You can setup most things in the config file. 

Of course input configuration and menu configuration are both
separate.

One detail glossed over in mplayer documentation is how to invoke
the menus from input.conf.

All you need is this in your input.conf

MOUSE_BTN0 menu main

This will invoke the menu if you click the left mouse button.

And in the menu.conf file you need to have a section which looks
like this.

<cmdlist name="main" title="MPlayer OSD menu" ptr="<>" >
     <e name="Pause" ok="pause"/>
     <e name="Prev/Next" ok="pt_step 1" cancel="pt_step -1"/>
     <e name="Jump to ..." ok="set_menu jump_to"/>
     <e name="Open ..." ok="set_menu open_file"/>
     <e name="Open playlist ..." ok="set_menu open_list"/>
     <e name="Help" ok="set_menu man"/>
     <e name="Pref" ok="set_menu pref_main"/>
     <e name="Properties" ok="set_menu properties"/>
     <e name="Console" ok="set_menu console0"/>
     <e name="Quit" ok="quit"/>
</cmdlist>

Let us come to a very related topic of displaying subtitles with 
mplayer. Not surpringly mplayer understands close to 12 subtitle 
formats and it has its own MPSub format too.

And the knobs for subtitle display are the richest I have seen.

You can display them in any size, any position on the video,
dynamically move them with the keyboard, adjust the delay, change
the transparency, format them into multiple lines and so on. 

The most basic usage of this file subtitles.txt with a video is


FORMAT=TIME
# first number  : wait this much after previous subtitle disappeared
# second number : display the current subtitle for this many seconds

2 3
What is going on?

4 3
How are you doing?

8 3
You are wrong!

0 3
A long long, time ago...
in a galaxy far away...

0 3
Naboo was under an attack.

0 200
I don't understand this.

$ mplayer -sub subtitles.txt -font ~/.ttffonts/Verdana.ttf video.avi

will display subtitles with the font of your choice.

And this will dump the subtitles file into the famous srt format.

$ mplayer -sub subtitles.txt video.avi -dumpsrtsub

You can have a quick look at all subtitles in the file by pressing
the 'y' and 'g' keys. Of course you can specify multiple subtitle 
files and you can switch between them.

Want to take screenshots with mplayer?

Easy.

$ mplayer -vf screenshot video.avi

Pressing 's' will take a screenshot.

If you want a screenshot every 5 seconds, you can try this.

$ mplayer -vo png -vf screenshot -sstep 5 video.avi

What if you want to take a screenshot of every frame?

Setup mplayer to accept slave commands with a fifo and type this.

$ mkfifo /tmp/fifo
$ mplayer -input file:/tmp/fifo video.mpg
$ echo 'screenshot 1' > /tmp/fifo

to begin and toggle it with

$ echo 'screenshot 1' > /tmp/fifo

whilst the file is playing.

It really makes me think if any GUI player can match this power. 

You might want to use the -vf spp,scale=1024:768 switch to get
fullscreen screenshots.

You can both encode image files into a video and extract frames into
image files with mplayer. 

You can also watch analog television with the tv:// option and watch
DVB channels with dvb:// options. 

It supports a wide variety of streaming protocols including RTP, RTSP,
 MMS, SDP and LIVE5555 streaming.

 What makes it cool is its ability to combine this with other mplayer's
 magic or linux command line processing.

 Now let us get to the topic of DVDs.

 Simply insert the DVD into the drive and type

 $ mplayer dvd://

 But alas we have a problem here. mplayer does not recognize DVD menus.

 Usually that is not a problem but I would think it is a serious 
 limitation. You have to use xine or ogle for DVD menu support.

 $ mplayer dvd://1-5 -dvd-device dvd/ -chapter 7

 will use the directory dvd/ as DVD root and start from chapter 7.

 You can switch titles (between 1 to 5) using the usual keys '<' and '>'
 and seek to chapters within titles using the mouse or keyboard.

 mplayer automatically does the CSS decrypting for you with libdvdcss.
 I have often found it work much better and faster than xine.

 You can adjust the hue, saturation and other attributes like GUI
 players using the keyboard or OSD menus. Of course you can do this with
 the command line too using the hue and eq video filters.

 You should definitely play with multiple video output drivers. Mplayer has
 amazing support for them.

 A video driver with hardware support for scaling and YUV colorspaces
 is certain preferred. Something like native support or using the 
 Xvideo extension known as xv. 

 If you are not lucky enough to get this working you have to get the CPU 
 to do all the hard work for you and this can get messy very soon.

 $ mplayer -vo help

 will list the compiled in video output drivers.

 You can play an arbitrary audio file with the video using

 $ mplayer video.mpg -audiofile audio.aac

 Of course mplayer can play a wide variety of audio and video media
 files.

 $ mplayer -vo help

 $ mplayer -ao help

 will satisfy your curiosity quite nicely.

 Occassionally however mplayer will stutter where mpg321 will not.

 You can try using the -audio-demuxer switch along with -rawaudio.

 mplayer has an extremely sophisticated A/V sync correction mechanism
 built into the design from the very beginning.

 This makes it stand out from any other player.

 You can do further by using -mc 0.001 or -autosync 20 or something.

 But if your machine is slow or your video output driver is not optimal,
 then -framedrop will help.

 This of course means your video will be choppy and ugly. Usually this
 happens when scaling the video in software. 

 In case you recorded video and audio from multiple sources and you wish
 to correct them with a fixed offset the -audio-delay parameter will help.

 You can specify a negative or positive value to delay the video or
 audio.

 In the next issue, we will check some of the advanced video filters 
 of mplayer and transcoding videos  with mplayer's close companion 
 mencoder.

 Resources:

 Mplayer home page: http://mplayerhq.hu
 Mplayer html documentation: http://www.mplayerhq.hu/DOCS/HTML-single/en/MPlayer.html
 Mplayer tips: http://freshmeat.net/articles/view/747/