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<chapter id="usage">
<title>Usage</title>

<sect1 id="commandline">
<title>Command line</title>

<para>
<application>MPlayer</application> utilizes a complex playtree. Options passed
on the command line can apply to all files/URLs or just to specific ones
depending on their position. For example
<screen>mplayer -vfm ffmpeg movie1.avi movie2.avi</screen>
will use FFmpeg decoders for both files, but
<screen>
mplayer -vfm ffmpeg <replaceable>movie1.avi</replaceable> <replaceable>movie2.avi</replaceable> -vfm dmo
</screen>
will play the second file with a DMO decoder.
</para>

<para>
You can group filenames/URLs together using <literal>{</literal> and
<literal>}</literal>. It is useful with option <option>-loop</option>:
<screen>mplayer { 1.avi -loop 2 2.avi } -loop 3</screen>
The above command will play files in this order: 1, 1, 2, 1, 1, 2, 1, 1, 2.
</para>

<para>
Playing a file:
<synopsis>
<command>mplayer</command><!--
--> [<replaceable>options</replaceable>]<!--
--> [<replaceable>path</replaceable>/]<replaceable>filename</replaceable>
</synopsis>
</para>

<para>
Another way to play a file:
<synopsis>
<command>mplayer</command><!--
--> [<replaceable>options</replaceable>]<!--
--> <replaceable>file:///uri-escaped-path</replaceable>
</synopsis>
</para>

<para>
Playing more files:
<synopsis>
<command>mplayer</command><!--
--> [<replaceable>default options</replaceable>]<!--
--> [<replaceable>path</replaceable>/]<replaceable>filename1</replaceable><!--
--> [<replaceable>options for filename1</replaceable>]<!--
--> <replaceable>filename2</replaceable><!--
--> [<replaceable>options for filename2</replaceable>] ...
</synopsis>
</para>

<para>
Playing VCD:
<synopsis>
<command>mplayer</command> [<replaceable>options</replaceable>]<!--
--> vcd://<replaceable>trackno</replaceable><!--
--> [-cdrom-device <replaceable>/dev/cdrom</replaceable>]
</synopsis>
</para>

<para>
Playing DVD:
<synopsis>
<command>mplayer</command> [<replaceable>options</replaceable>]<!--
--> dvd://<replaceable>titleno</replaceable><!--
--> [-dvd-device <replaceable>/dev/dvd</replaceable>]
</synopsis>
</para>

<para>
Playing from the WWW:
<synopsis>
<command>mplayer</command> [<replaceable>options</replaceable>]<!--
--> http://<replaceable>site.com/file.asf</replaceable>
</synopsis>
(playlists can be used, too)
</para>

<para>
Playing from RTSP:
<synopsis>
<command>mplayer</command> [<replaceable>options</replaceable>]<!--
--> rtsp://<replaceable>server.example.com/streamName</replaceable>
</synopsis>
</para>

<para>
Examples:
<screen>
mplayer -vo x11 <replaceable>/mnt/Films/Contact/contact2.mpg</replaceable>
mplayer vcd://<replaceable>2</replaceable> -cdrom-device <replaceable>/dev/hdc</replaceable>
mplayer -afm 3 <replaceable>/mnt/DVDtrailers/alien4.vob</replaceable>
mplayer dvd://<replaceable>1</replaceable> -dvd-device <replaceable>/dev/hdc</replaceable>
mplayer -abs 65536 -delay -0.4 -nobps <replaceable>~/movies/test.avi</replaceable><!--
--></screen>
</para>
</sect1>


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<sect1 id="subosd">
<title>Subtitles and OSD</title>

<para>
<application>MPlayer</application> can display subtitles along with movie files.
Currently the following formats are supported:
<itemizedlist>
  <listitem><para>VOBsub</para></listitem>
  <listitem><para>OGM</para></listitem>
  <listitem><para>CC (closed caption)</para></listitem>
  <listitem><para>MicroDVD</para></listitem>
  <listitem><para>SubRip</para></listitem>
  <listitem><para>SubViewer</para></listitem>
  <listitem><para>Sami</para></listitem>
  <listitem><para>VPlayer</para></listitem>
  <listitem><para>RT</para></listitem>
  <listitem><para>SSA</para></listitem>
  <listitem><para>PJS (Phoenix Japanimation Society)</para></listitem>
  <listitem><para>MPsub</para></listitem>
  <listitem><para>AQTitle</para></listitem>
  <listitem><para>
    <ulink url="http://unicorn.us.com/jacosub/">JACOsub</ulink>
  </para></listitem>
</itemizedlist>
</para>

<para>
<application>MPlayer</application> can dump the previously listed subtitle
formats (<emphasis role="bold">except the three first</emphasis>) into the
following destination formats, with the given options:
<itemizedlist>
  <listitem><para>MPsub: <option>-dumpmpsub</option></para></listitem>
  <listitem><para>SubRip: <option>-dumpsrtsub</option></para></listitem>
  <listitem><para>MicroDVD: <option>-dumpmicrodvdsub</option></para></listitem>
  <listitem><para>JACOsub: <option>-dumpjacosub</option></para></listitem>
  <listitem><para>Sami: <option>-dumpsami</option></para></listitem>
</itemizedlist>
</para>

<para>
<application>MEncoder</application> can dump DVD subtitles into
<link linkend="menc-feat-extractsub">VOBsub</link> format.
</para>

<para>
The command line options differ slightly for the different formats:
</para>

<formalpara>
<title>VOBsub subtitles</title>
<para>
VOBsub subtitles consist of a big (some megabytes) <filename>.SUB</filename>
file, and optional <filename>.IDX</filename> and/or <filename>.IFO</filename>
files. If you have files like
<filename><replaceable>sample.sub</replaceable></filename>,
<filename><replaceable>sample.ifo</replaceable></filename> (optional),
<filename><replaceable>sample.idx</replaceable></filename> - you have to pass
<application>MPlayer</application> the <option>-vobsub sample
[-vobsubid <replaceable>id</replaceable>]</option> options
(full path optional). The <option>-vobsubid</option> option is like
<option>-sid</option> for DVDs, you can choose between subtitle tracks
(languages) with it. In case that <option>-vobsubid</option> is omitted,
<application>MPlayer</application> will try to use the languages given by the
<option>-slang</option> option and fall back to the
<systemitem>langidx</systemitem> in the <filename>.IDX</filename> file to set
the subtitle language. If it fails, there will be no subtitles.
</para>
</formalpara>

<formalpara>
<title>Other subtitles</title>
<para>
The other formats consist of a single text file containing timing,
placement and text information. Usage: If you have a file like
<filename><replaceable>sample.txt</replaceable></filename>,
you have to pass the option <option>-sub
<replaceable>sample.txt</replaceable></option> (full path optional).
</para>
</formalpara>

<variablelist>
<title>Adjusting subtitle timing and placement:</title>
<varlistentry>
  <term><option>-subdelay <replaceable>sec</replaceable></option></term>
  <listitem><para>
    Delays subtitles by <option><replaceable>sec</replaceable></option> seconds.
    Can be negative. The value is added to movie's time position counter.
  </para></listitem>
</varlistentry>
<varlistentry>
  <term><option>-subfps <replaceable>RATE</replaceable></option></term>
  <listitem><para>
    Specify frame/sec rate of subtitle file (float number).
  </para></listitem>
</varlistentry>
<varlistentry>
  <term><option>-subpos <replaceable>0-100</replaceable></option></term>
  <listitem><para>
    Specify the position of subtitles.
  </para></listitem>
</varlistentry>
</variablelist>

<para>
If you experience a growing delay between the movie and the subtitles when
using a MicroDVD subtitle file, most likely the framerate of the movie and
the subtitle file are different. Please note that the MicroDVD subtitle
format uses absolute frame numbers for its timing, but there is no fps
information in it, and therefore the <option>-subfps</option> option should
be used with this format. If you like to solve this problem permanently,
you have to manually convert the subtitle file framerate.
<application>MPlayer</application> can do this
conversion for you:

<screen>
mplayer -dumpmicrodvdsub -fps <replaceable>subtitles_fps</replaceable> -subfps <replaceable>avi_fps</replaceable> \
    -sub <replaceable>subtitle_filename</replaceable> <replaceable>dummy.avi</replaceable>
</screen>
</para>

<para>
About DVD subtitles, read the <link linkend="dvd">DVD</link> section.
</para>
</sect1>


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<sect1 id="control">
<title>Control</title>

<para>
<application>MPlayer</application> has a fully configurable, command
driven, control layer which lets you control
<application>MPlayer</application> with keyboard, mouse, joystick or remote
control (using LIRC). See the man page for the complete list of keyboard controls.
</para>

<!-- ********** -->

<sect2 id="ctrl-cfg">
<title>Controls configuration</title>

<para>
<application>MPlayer</application> allows you bind any key/button to any
<application>MPlayer</application> command using a simple config file.
The syntax consist of a key name followed by a command. The default config file location is
<filename>$HOME/.mplayer/input.conf</filename> but it can be overridden
using the <option>-input <replaceable>conf</replaceable></option> option
(relative path are relative to <filename>$HOME/.mplayer</filename>).
</para>

<para>
You can get a full list of supported key names by running
<command>mplayer -input keylist</command>
and a full list of available commands by running
<command>mplayer -input cmdlist</command>.
</para>

<example id="input_control_file">
<title>A simple input control file</title>
<programlisting>
##
## MPlayer input control file
##

RIGHT seek +10
LEFT seek -10
- audio_delay 0.100
+ audio_delay -0.100
q quit
&gt; pt_step 1
&lt; pt_step -1
ENTER pt_step 1 1<!--
--></programlisting>
</example>
</sect2>

<!-- ********** -->

<sect2 id="lirc">
<title>Control from LIRC</title>

<para>
Linux Infrared Remote Control - use an easy to build home-brewed IR-receiver,
an (almost) arbitrary remote control and control your Linux box with it!
More about it on the <ulink url="http://www.lirc.org">LIRC homepage</ulink>.
</para>

<para>
If you have the LIRC package installed, <filename>configure</filename> will
autodetect it. If everything went fine, <application>MPlayer</application>
will print "<systemitem>Setting up LIRC support...</systemitem>"
on startup. If an error occurs it will tell you. If there is no message about
LIRC there is no support compiled in. That's it :-)
</para>

<para>
The application name for <application>MPlayer</application> is - surprise -
<filename>mplayer</filename>. You can use any <application>MPlayer</application>
commands and even pass more than one command by separating them with
<literal>\n</literal>.
Do not forget to enable the repeat flag in <filename>.lircrc</filename> when
it makes sense (seek, volume, etc). Here is an excerpt from a sample
<filename>.lircrc</filename>:
</para>

<programlisting>
begin
     button = VOLUME_PLUS
     prog = mplayer
     config = volume 1
     repeat = 1
end

begin
    button = VOLUME_MINUS
    prog = mplayer
    config = volume -1
    repeat = 1
end

begin
    button = CD_PLAY
    prog = mplayer
    config = pause
end

begin
    button = CD_STOP
    prog = mplayer
    config = seek 0 1\npause
end<!--
--></programlisting>

<para>
If you do not like the standard location for the lirc-config file
(<filename>~/.lircrc</filename>) use the <option>-lircconf
<replaceable>filename</replaceable></option> switch to specify another
file.
</para>
</sect2>

<!-- ********** -->

<sect2 id="slave-mode">
<title>Slave mode</title>

<para>
The slave mode allows you to build simple frontends to
<application>MPlayer</application>. When run with the
<option>-slave</option> option <application>MPlayer</application> will
read commands separated by a newline (\n) from stdin.
The commands are documented in the
<ulink url="../../tech/slave.txt">slave.txt</ulink> file.
</para>
</sect2>
</sect1>


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<sect1 id="streaming">
<title>Streaming from network or pipes</title>

<para>
<application>MPlayer</application> can play files from the network, using the
HTTP, FTP, MMS or RTSP/RTP protocol.
</para>

<para>
Playing works simply by passing the URL on the command line.
<application>MPlayer</application> honors the <envar>http_proxy</envar>
environment variable, using a proxy if available. Proxies can also be forced:
<screen>
mplayer <replaceable>http_proxy://proxy.micorsops.com:3128/http://micorsops.com:80/stream.asf</replaceable>
</screen>
</para>

<para>
<application>MPlayer</application> can read from stdin
(<emphasis>not</emphasis> named pipes). This can for example be used to
play from FTP:
<screen>
wget <replaceable>ftp://micorsops.com/something.avi</replaceable> -O - | mplayer -
</screen>
</para>

<note><para>
It is also recommended to enable <option>-cache</option> when playing
from the network:
<screen>
wget <replaceable>ftp://micorsops.com/something.avi</replaceable> -O - | mplayer -cache 8192 -
</screen>
</para></note>

<!-- ********** -->

<sect2 id="streaming-save">
<title>Saving streamed content</title>

<para>
Once you succeed in making <application>MPlayer</application> play
your favorite internet stream, you can use the option
<option>-dumpstream</option> to save the stream into a file.
For example:
<screen>
mplayer <replaceable>http://217.71.208.37:8006</replaceable> -dumpstream -dumpfile <replaceable>stream.asf</replaceable>
</screen>
will save the content streamed from
<replaceable>http://217.71.208.37:8006</replaceable> into
<replaceable>stream.asf</replaceable>.
This works with all protocols supported by
<application>MPlayer</application>, like MMS, RTSP, and so forth.
</para>
</sect2>
</sect1>


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<sect1 id="dvd">
<title>DVD playback</title>

<para>
For the complete list of available options, please read the man page.
The syntax to play a standard DVD is as follows:
<screen>
mplayer dvd://<replaceable>&lt;track&gt;</replaceable> [-dvd-device <replaceable>&lt;device&gt;</replaceable>]
</screen>
</para>

<para>
Example:
<screen>mplayer dvd://1 -dvd-device /dev/hdc</screen>
</para>

<para>
If you have compiled <application>MPlayer</application> with dvdnav support, the
syntax is the same, except that you need to use dvdnav:// instead of dvd://.
</para>

<para>
The default DVD device is <filename>/dev/dvd</filename>. If your setup
differs, make a symlink or specify the correct device on the command
line with the <option>-dvd-device</option> option.
</para>

<para>
<application>MPlayer</application> uses <systemitem>libdvdread</systemitem> and
<systemitem>libdvdcss</systemitem> for DVD playback and decryption. These two
libraries are contained in the
<application>MPlayer</application> source tree, you do not have
to install them separately. You can also use system-wide versions of the two
libraries, but this solution is not recommended, as it can result in bugs,
library incompatibilities and slower speed.
</para>

<note><para>
In case of DVD decoding problems, try disabling supermount, or any other such
facilities. Some RPC-2 drives may also require setting the region code.
</para></note>

<formalpara>
<title>DVD decryption</title>
<para>
DVD decryption is done by <systemitem>libdvdcss</systemitem>. The method
can be specified through the <envar>DVDCSS_METHOD</envar> environment
variable, see the manual page for details.
</para>
</formalpara>

<!-- ********** -->

<sect2 id="region_code">
<title>region code</title>
<para>
DVD drives nowadays come with a nonsensical restriction labeled
<ulink url="http://en.wikipedia.org/wiki/DVD_region_code">region code</ulink>.
This is a scheme to force DVD drives to only accept DVDs produced for one of
the six different regions into which the world was partitioned. How a group
of people can sit around a table, come up with such an idea and expect the
world of the 21st century to bow to their will is beyond anyone's guess.
</para>

<para>
Drives that enforce region settings through software only are also known as
RPC-1 drives, those that do it in hardware as RPC-2. RPC-2 drives allow
changing the region code five times before it remains fixed.
Under Linux you can use the
<ulink url="http://linvdr.org/projects/regionset/">regionset</ulink> tool
to set the region code of your DVD drive.
</para>

<para>
Thankfully, it is possible to convert RPC-2 drives into RPC-1 drives through
a firmware upgrade. Feed the model number of your DVD drive into your favorite
search engine or have a look at the forum and download sections of
<ulink url="http://www.rpc1.org/">"The firmware page"</ulink>.
While the usual caveats for firmware upgrades apply, experience with
getting rid of region code enforcement is generally positive.
</para>
</sect2>
</sect1>


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<sect1 id="vcd">
<title>VCD playback</title>

<para>
For the complete list of available options, please read the man page. The
Syntax for a standard Video CD (VCD) is as follows:
<screen>mplayer vcd://<replaceable>&lt;track&gt;</replaceable> [-cdrom-device <replaceable>&lt;device&gt;</replaceable>]</screen>
Example:
<screen>mplayer vcd://2 -cdrom-device /dev/hdc</screen>
The default VCD device is <filename>/dev/cdrom</filename>. If your setup
differs, make a symlink or specify the correct device on the command line
with the <option>-cdrom-device</option> option.
</para>

<note><para>
At least Plextor and some Toshiba SCSI CD-ROM drives have horrible performance
reading VCDs. This is because the CDROMREADRAW <systemitem>ioctl</systemitem>
is not fully implemented for these drives. If you have some knowledge of SCSI
programming, please <ulink url="../../tech/patches.txt">help us</ulink>
implement generic SCSI support for VCDs.
</para></note>

<para>
In the meantime you can extract data from VCDs with
<ulink url="http://ftp.ntut.edu.tw/ftp/OS/Linux/packages/X/viewers/readvcd/">readvcd</ulink>
and play the resulting file with <application>MPlayer</application>.
</para>

<formalpara>
<title>VCD structure</title>
<para>
A Video CD (VCD) is made up of CD-ROM XA sectors, i.e. CD-ROM mode 2
form 1 and 2 tracks:
<itemizedlist>
<listitem><para>
  The first track is in mode 2 form 2 format which means it uses L2
  error correction. The track contains an ISO-9660 file system with 2048
  bytes/sector. This file system contains VCD metadata information, as
  well as still frames often used in menus. MPEG segments for menus can
  also be stored in this first track, but the MPEGs have to be broken up
  into a series of 150-sector chunks. The ISO-9660 file system may
  contain other files or programs that are not essential for VCD
  operation.
</para></listitem>

<listitem><para>
  The second and remaining tracks are generally raw 2324 bytes/sector
  MPEG (movie) tracks, containing one MPEG PS data packet per
  sector. These are in mode 2 form 1 format, so they store more data per
  sector at the loss of some error correction. It is also legal to have
  CD-DA tracks in a VCD after the first track as well.
  On some operating systems there is some trickery that goes on to make
  these non-ISO-9660 tracks appear in a file system. On other operating
  systems like GNU/Linux this is not the case (yet). Here the MPEG data
  <emphasis role="bold">cannot be mounted</emphasis>. As most movies are
  inside this kind of track, you should try <option>vcd://2</option>
  first.
</para></listitem>

<listitem><para>
  There exist VCD disks without the first track (single track and no file system
  at all). They are still playable, but cannot be mounted.
</para></listitem>

<listitem><para>
  The definition of the Video CD standard is called the
  Philips "White Book" and it is not generally available online as it
  must be purchased from Philips. More detailed information about Video
  CDs can be found in the
  <ulink url="http://www.vcdimager.org/pub/vcdimager/manuals/0.7/vcdimager.html#SEC4">vcdimager documentation</ulink>.
</para></listitem>
</itemizedlist>
</para>
</formalpara>

<formalpara>
<title>About .DAT files</title>
<para>
The ~600 MB file visible on the first track of the mounted VCD is not a real
file! It is a so called ISO gateway, created to allow Windows to handle such
tracks (Windows does not allow raw device access to applications at all).
Under Linux you cannot copy or play such files (they contain garbage). Under
Windows it is possible as its iso9660 driver emulates the raw reading of
tracks in this file. To play a .DAT file you need the kernel driver which can
be found in the Linux version of PowerDVD. It has a modified iso9660 file system
(<filename>vcdfs/isofs-2.4.X.o</filename>) driver, which is able to emulate the
raw tracks through this shadow .DAT file. If you mount the disc using their
driver, you can copy and even play .DAT files with
<application>MPlayer</application>. But it will not
work with the standard iso9660 driver of the Linux kernel! Use
<option>vcd://</option> instead. Alternatives for VCD copying are the
new <ulink url="http://www.elis.rug.ac.be/~ronsse/cdfs/">cdfs</ulink> kernel
driver (not part of the official kernel) that shows CD sessions as image files
and <ulink url="http://cdrdao.sf.net/">cdrdao</ulink>, a bit-by-bit
CD grabbing/copying application.
</para>
</formalpara>
</sect1>


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<sect1 id="edl" xreflabel="Edit Decision Lists (EDL)">
<title>Edit Decision Lists (EDL)</title>

<para>
The edit decision list (EDL) system allows you to automatically skip
or mute sections of videos during playback, based on a movie specific
EDL configuration file.
</para>

<para>
This is useful for those who may want to watch a film in "family-friendly"
mode. You can cut out any violence, profanity, Jar-Jar Binks .. from a movie
according to your own personal preferences. Aside from this, there are other
uses, like automatically skipping over commercials in video files you watch.
</para>

<para>
The EDL file format is pretty bare-bones. There is one command per line that
indicates what to do (skip/mute) and when to do it (using pts in seconds).
</para>

<!-- ********** -->

<sect2 id="edl_using">
<title>Using an EDL file</title>

<para>
Include the <option>-edl &lt;filename&gt;</option> flag when you run
<application>MPlayer</application>, with the name of the EDL file you
want applied to the video.
</para>
</sect2>

<!-- ********** -->

<sect2 id="edl_making">
<title>Making an EDL file</title>

<para>
The current EDL file format is:
<programlisting>[begin second] [end second] [action]</programlisting>
Where the seconds are floating-point numbers and the action is either
<literal>0</literal> for skip or <literal>1</literal> for mute. Example:
<programlisting>
5.3   7.1    0
15    16.7   1
420   422    0
</programlisting>
This will skip from second 5.3 to second 7.1 of the video, then mute at
15 seconds, unmute at 16.7 seconds and skip from second 420 to second 422
of the video. These actions will be performed when the playback timer
reaches the times given in the file.
</para>

<para>
To create an EDL file to work from, use the <option>-edlout
&lt;filename&gt;</option> flag. During playback, just hit <keycap>i</keycap> to
mark the beginning and end of a skip block.
A corresponding entry will be written to the file for that time.
You can then go back and fine-tune the generated EDL file as well as
change the default operation which is to skip the block described by each line.
</para>
</sect2>
</sect1>

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<sect1 id="networksync" xreflabel="Network Synchronized Playback">
<title>Synchronized playback over a network</title>

<para>
Multiple instances of <application>MPlayer</application> can synchronize
playback over a network. This is useful for creating "video walls" with
multiple screens controlled by different computers. Each
<application>MPlayer</application> instance can
play a different video, but they all will try to stay at the same time offset
in the file. It is recommended but not necessary to encode the video files
using the same codec and parameters.
</para>

<para>The relevant options are <option>-udp-master</option>,
  <option>-udp-slave</option>, <option>-udp-ip</option>,
  <option>-udp-port</option>, and <option>-udp-seek-threshold</option>.
</para>

<para>
If <option>-udp-master</option> is given, <application>MPlayer</application>
sends a datagram to <option>-udp-ip</option> (default: 127.0.0.1)
on <option>-udp-port</option> (default: 23867) just before playing each frame.
The datagram indicates the master's position in the file. If
<option>-udp-slave</option> is given, <application>MPlayer</application> listens on
<option>-udp-ip</option>/<option>-udp-port</option>
and matches the master's position. Setting <option>-udp-ip</option> to the
master's broadcast address allows multiple slaves having the same broadcast
address to sync to the master. Note that this feature assumes an
ethernet-like low-latency network connection. Your mileage may vary on high
latency networks.
</para>

<para>
For example, assume 8 computers are on a network, with IP addresses 192.168.0.1
through 192.168.0.8. Assume the first computer is to be the master. Running
ifconfig on all the machines lists "Bcast:192.168.0.255". On the master, run:
</para>

<screen>
mplayer -udp-master -udp-ip 192.168.0.255 video1.mpg
</screen>

<para>
On each slave, run:
</para>

<screen>
mplayer -udp-slave -udp-ip 192.168.0.255 videoN.mpg
</screen>

<para>
Seeking, pausing and even playback speed adjustment (see the
<option>-input</option> option) can be done on the master, and all the slaves
will follow. When the master exits, it sends out a "bye" message which causes
the slaves to exit as well.
</para>

</sect1>

<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

<sect1 id="advaudio-surround">
<title>Surround/Multichannel playback</title>

<sect2 id="advaudio-surround-DVD">
<title>DVDs</title>

<para>
Most DVDs and many other files include surround sound.
<application>MPlayer</application> supports surround playback but does not
enable it by default because stereo equipment is by far more common. To play a
file that has more than two channels of audio use <option>-channels</option>.
For example, to play a DVD with 5.1 audio:
<screen>mplayer dvd://1 -channels 6</screen>
Note that despite the name "5.1" there are actually six discrete channels.
If you have surround sound equipment it is safe to put the
<option>channels</option> option in your <application>MPlayer</application>
configuration file <filename>~/.mplayer/config</filename>. For example, to make
quadraphonic playback the default, add this line:
<programlisting>channels=4</programlisting>
<application>MPlayer</application> will then output audio in four channels when
all four channels are available.
</para>
</sect2>


<sect2 id="advaudio-surround-stereoinfour">
<title>Playing stereo files to four speakers</title>

<para>
<application>MPlayer</application> does not duplicate any channels by default,
and neither do most audio drivers. If you want to do that manually:
<screen>mplayer <replaceable>filename</replaceable> -af channels=2:2:0:1:0:0</screen>
See the section on
<link linkend="advaudio-channels-copying">channel copying</link> for an
explanation.
</para>
</sect2>


<sect2 id="advaudio-surround-passthrough">
<title>AC-3/DTS Passthrough</title>

<para>
DVDs usually have surround audio encoded in AC-3 (Dolby Digital) or DTS
(Digital Theater System) format. Some modern audio equipment is capable of
decoding these formats internally. <application>MPlayer</application> can be
configured to relay the audio data without decoding it. This will only work if
you have a S/PDIF (Sony/Philips Digital Interface) jack in your sound card, or
if you are passing audio over HDMI.
</para>

<para>
If your audio equipment can decode both AC-3 and DTS, you can safely enable
passthrough for both formats. Otherwise, enable passthrough for only the format
your equipment supports.
</para>

<itemizedlist>
<title>To enable passthrough on the command line:</title>
<listitem><para>
  For AC-3 only, use <option>-ac hwac3</option>
</para></listitem>
<listitem><para>
  For DTS only, use <option>-ac hwdts</option>
</para></listitem>
<listitem><para>
  For both AC-3 and DTS, use <option>-afm hwac3</option>
</para></listitem>
</itemizedlist>

<itemizedlist>
<title>To enable passthrough in the <application>MPlayer</application>
  configuration file: </title>
<listitem><para>
  For AC-3 only, use <option>ac=hwac3,</option>
</para></listitem>
<listitem><para>
  For DTS only, use <option>ac=hwdts,</option>
</para></listitem>
<listitem><para>
  For both AC-3 and DTS, use <option>afm=hwac3</option>
</para></listitem>
</itemizedlist>

<para>
Note that there is a comma (",") at the end of
<option>ac=hwac3,</option> and <option>ac=hwdts,</option>. This will make
<application>MPlayer</application> fall back on the codecs it normally uses when
playing a file that does not have AC-3 or DTS audio.
<option>afm=hwac3</option> does not need a comma;
<application>MPlayer</application> will fall back anyway when an audio family
is specified.
</para>
</sect2>


<sect2 id="hwmpa-surround-passthrough">
<title>MPEG audio Passthrough</title>

<para>
Digital TV transmissions (such as DVB and ATSC) and some DVDs usually have
MPEG audio streams (in particular MP2).
Some MPEG hardware decoders such as full-featured DVB cards and DXR2
adapters can natively decode this format.
<application>MPlayer</application> can be configured to relay the audio data
without decoding it.
</para>

<para>
To use this codec:
<screen> mplayer -ac hwmpa </screen>
</para>
</sect2>


<sect2 id="advaudio-surround-matrix">
<title>Matrix-encoded audio</title>

<para>
<emphasis>***TODO***</emphasis>
</para>

<para>
This section has yet to be written and cannot be completed until somebody
provides sample files for us to test. If you have any matrix-encoded audio
files, know where to find some, or have any information that could be helpful,
please send a message to the
<ulink url="http://lists.mplayerhq.hu/mailman/listinfo/mplayer-docs">MPlayer-DOCS</ulink>
mailing list. Put "[matrix-encoded audio]" in the subject line.
</para>

<para>
If no files or further information are forthcoming this section will be dropped.
</para>

<para>
Good links:
<itemizedlist>
<listitem><para>
  <ulink url="http://electronics.howstuffworks.com/surround-sound5.htm">http://electronics.howstuffworks.com/surround-sound5.htm</ulink>
</para></listitem>
<listitem><para>
  <ulink url="http://www.extremetech.com/article2/0,1697,1016875,00.asp">http://www.extremetech.com/article2/0,1697,1016875,00.asp</ulink>
</para></listitem>
</itemizedlist>
</para>
</sect2>


<sect2 id="advaudio-surround-hrtf">
<title>Surround emulation in headphones</title>

<para>
<application>MPlayer</application> includes an HRTF (Head Related Transfer
Function) filter based on an
<ulink url="http://sound.media.mit.edu/KEMAR.html">MIT project</ulink>
wherein measurements were taken from microphones mounted on a dummy human head.
</para>

<para>
Although it is not possible to exactly imitate a surround system,
<application>MPlayer</application>'s HRTF filter does provide more spatially
immersive audio in 2-channel headphones. Regular downmixing simply combines all
the channels into two; besides combining the channels, <option>hrtf</option>
generates subtle echoes, increases the stereo separation slightly, and alters
the volume of some frequencies. Whether HRTF sounds better may be dependent on
the source audio and a matter of personal taste, but it is definitely worth
trying out.
</para>

<para>
To play a DVD with HRTF:
<screen>mplayer dvd://1 -channels 6 -af hrtf</screen>
</para>

<para>
<option>hrtf</option> only works well with 5 or 6 channels. Also,
<option>hrtf</option> requires 48 kHz audio. DVD audio is already 48 kHz, but if
you have a file with a different sampling rate that you want to play using
<option>hrtf</option> you must resample it:
<screen>
mplayer <replaceable>filename</replaceable> -channels 6 -af resample=48000,hrtf
</screen>
</para>
</sect2>


<sect2 id="advaudio-surround-troubleshooting">
<title>Troubleshooting</title>

<para>
If you do not hear any sound out of your surround channels, check your mixer
settings with a mixer program such as <application>alsamixer</application>;
audio outputs are often muted and set to zero volume by default.
</para>
</sect2>
</sect1>

<!-- ********** -->

<sect1 id="advaudio-channels">
<title>Channel manipulation</title>

<sect2 id="advaudio-channels-general">
<title>General information</title>

<para>
Unfortunately, there is no standard for how channels are ordered. The orders
listed below are those of AC-3 and are fairly typical; try them and see if your
source matches. Channels are numbered starting with 0.

<orderedlist spacing="compact">
<title>mono</title>
  <listitem override="0"><para>center</para></listitem>
</orderedlist>

<orderedlist spacing="compact">
<title>stereo</title>
  <listitem override="0"><para>left</para></listitem>
  <listitem><para>right</para></listitem>
</orderedlist>

<orderedlist spacing="compact">
<title>quadraphonic</title>
  <listitem override="0"><para>left front</para></listitem>
  <listitem><para>right front</para></listitem>
  <listitem><para>left rear</para></listitem>
  <listitem><para>right rear</para></listitem>
</orderedlist>

<orderedlist spacing="compact">
<title>surround 4.0</title>
  <listitem override="0"><para>left front</para></listitem>
  <listitem><para>right front</para></listitem>
  <listitem><para>center rear</para></listitem>
  <listitem><para>center front</para></listitem>
</orderedlist>

<orderedlist spacing="compact">
<title>surround 5.0</title>
  <listitem override="0"><para>left front</para></listitem>
  <listitem><para>right front</para></listitem>
  <listitem><para>left rear</para></listitem>
  <listitem><para>right rear</para></listitem>
  <listitem><para>center front</para></listitem>
</orderedlist>

<orderedlist spacing="compact">
<title>surround 5.1</title>
  <listitem override="0"><para>left front</para></listitem>
  <listitem><para>right front</para></listitem>
  <listitem><para>left rear</para></listitem>
  <listitem><para>right rear</para></listitem>
  <listitem><para>center front</para></listitem>
  <listitem><para>subwoofer</para></listitem>
</orderedlist>
</para>

<para>
The <option>-channels</option> option is used to request the number of
channels from the audio decoder. Some audio codecs use the number of specified
channels to decide if downmixing the source is necessary. Note that this does
not always affect the number of output channels. For example, using
<option>-channels 4</option> to play a stereo MP3 file will still result in
2-channel output since the MP3 codec will not produce the extra channels.
</para>

<para>
The <option>channels</option> audio filter can be used to create or remove
channels and is useful for controlling the number of channels sent to the sound
card. See the following sections for more information on channel manipulation.
</para>
</sect2>


<sect2 id="advaudio-channels-mono">
<title>Playing mono with two speakers</title>

<para>
Mono sounds a lot better when played through two speakers - especially when
using headphones. Audio files that truly have one channel are automatically
played through two speakers; unfortunately, most files with mono sound are
actually encoded as stereo with one channel silent. The easiest and most
foolproof way to make both speakers output the same audio is the
<option>extrastereo</option> filter:
<screen>mplayer <replaceable>filename</replaceable> -af extrastereo=0</screen>
</para>

<para>
This averages both channels, resulting in both channels being half as loud as
the original. The next sections have examples of other ways to do this without a
volume decrease, but they are more complex and require different options
depending on which channel to keep. If you really need to maintain the volume,
it may be easier to experiment with the <option>volume</option> filter and find
the right value. For example:
<screen>
mplayer <replaceable>filename</replaceable> -af extrastereo=0,volume=5
</screen>
</para>
</sect2>


<sect2 id="advaudio-channels-copying">
<title>Channel copying/moving</title>

<para>
The <option>channels</option> filter can move any or all channels.
Setting up all the suboptions for the <option>channels</option>
filter can be complicated and takes a little care.

<orderedlist spacing="compact">
<listitem><para>
  Decide how many output channels you need. This is the first suboption.
</para></listitem>
<listitem><para>
  Count how many channel moves you will do. This is the second suboption. Each
  channel can be moved to several different channels at the same time, but keep
  in mind that when a channel is moved (even if to only one destination) the
  source channel will be empty unless another channel is moved into it. To copy
  a channel, keeping the source the same, simply move the channel into both the
  destination and the source. For example:
  <programlisting>
channel 2 --> channel 3
channel 2 --> channel 2<!--
  --></programlisting>
</para></listitem>
<listitem><para>
  Write out the channel copies as pairs of suboptions. Note that the first
  channel is 0, the second is 1, etc. The order of these suboptions does not
  matter as long as they are properly grouped into
  <replaceable>source:destination</replaceable> pairs.
</para></listitem>
</orderedlist>
</para>

<bridgehead>Example: one channel in two speakers</bridgehead>
<para>
Here is an example of another way to play one channel in both speakers. Suppose
for this example that the left channel should be played and the right channel
discarded. Following the steps above:
<orderedlist>
<listitem><para>
  In order to provide an output channel for each of the two speakers, the first
  suboption must be "2".
</para></listitem>
<listitem><para>
  The left channel needs to be moved to the right channel, and also must be
  moved to itself so it won't be empty. This is a total of two moves, making
  the second suboption "2" as well.
</para></listitem>
<listitem><para>
  To move the left channel (channel 0) into the right channel (channel 1), the
  suboption pair is "0:1", "0:0" moves the left channel onto itself.
</para></listitem>
</orderedlist>
Putting that all together gives:
<screen>
mplayer <replaceable>filename</replaceable> -af channels=2:2:0:1:0:0
</screen>
</para>

<para>
The advantage this example has over <option>extrastereo</option> is that the
volume of each output channel is the same as the input channel. The disadvantage
is that the suboptions must be changed to "2:2:1:0:1:1" when the desired audio
is in the right channel. Also, it is more difficult to remember and type.
</para>

<bridgehead>Example: left channel in two speakers shortcut</bridgehead>
<para>
There is actually a much easier way to use the <option>channels</option> filter
for playing the left channel in both speakers:
<screen>mplayer <replaceable>filename</replaceable> -af channels=1</screen>
The second channel is discarded and, with no further suboptions, the single
remaining channel is left alone. Sound card drivers automatically play
single-channel audio in both speakers. This only works when the desired channel
is on the left.
</para>

<bridgehead>Example: duplicate front channels to the rear</bridgehead>
<para>
Another common operation is to duplicate the front channels and play them back
on the rear speakers of a quadraphonic setup.
<orderedlist>
<listitem><para>
  There should be four output channels. The first suboption is "4".
</para></listitem>
<listitem><para>
  Each of the two front channels needs to be moved to the corresponding rear
  channel and also to itself. This is four moves, so the second suboption is "4".
</para></listitem>
<listitem><para>
  The left front (channel 0) needs to moved to the left rear (channel 2):
  "0:2".  The left front also needs to be moved to itself: "0:0". The right
  front (channel 1) is moved to the right rear (channel 3): "1:3", and also to
  itself: "1:1".
</para></listitem>
</orderedlist>
Combine all the suboptions to get:
<screen>
mplayer <replaceable>filename</replaceable> -af channels=4:4:0:2:0:0:1:3:1:1
</screen>
</para>
</sect2>


<sect2 id="advaudio-channels-mixing">
<title>Channel mixing</title>

<para>
The <option>pan</option> filter can mix channels in user-specified proportions.
This allows for everything the <option>channels</option> filter can do and
more. Unfortunately, the suboptions are much more complicated.
<orderedlist>
<listitem><para>
  Decide how many channels to work with. You may need to specify this with
  <option>-channels</option> and/or <option>-af channels</option>.
  Later examples will show when to use which.
</para></listitem>
<listitem><para>
  Decide how many channels to feed into <option>pan</option> (further decoded
  channels are discarded). This is the first suboption, and it also controls how
  many channels to employ for output.
</para></listitem>
<listitem>
  <para>
  The remaining suboptions specify how much of each channel gets mixed into each
  other channel. This is the complicated part. To break the task down, split the
  suboptions into several sets, one set for each input channel. Each suboption
  within a set corresponds to an output channel. The number you specify will be
  the percentage of the input channel that gets mixed into the output channel.
  </para>
  <para>
  <option>pan</option> accepts values from 0 to 512, yielding 0% to 51200% of
  the original volume. Be careful when using values greater than 1. Not only
  can this give you very high volume, but if you exceed the sample range of
  your sound card you may hear painful pops and clicks. If you want you can
  follow <option>pan</option> with <option>,volume</option> to enable clipping,
  but it is best to keep the values of <option>pan</option> low enough that
  clipping is not necessary.
  </para>
</listitem>
</orderedlist>
</para>

<bridgehead>Example: one channel in two speakers</bridgehead>
<para>
Here is yet another example for playing the left channel in two speakers. Follow
the steps above:
<orderedlist>
<listitem><para>
  <option>pan</option> should output two channels, so the first
  suboption is "2".
</para></listitem>
<listitem><para>
  Since we have two input channels, there will be two sets of suboptions.
  Since there are also two output channels,
  there will be two suboptions per set.
  The left channel from the file should go with full volume to
  the new left and the right channels.
  Thus the first set of suboptions is "1:1".
  The right channel should be discarded, so the second would be "0:0".
  Any 0 values at the end can be left out, but for ease of
  understanding we will keep them.
</para></listitem>
</orderedlist>
Putting those options together gives:
<screen>mplayer <replaceable>filename</replaceable> -af pan=2:1:1:0:0</screen>
If the right channel is desired instead of the left, the suboptions to
<option>pan</option> will be "2:0:0:1:1".
</para>


<bridgehead>Example: left channel in two speakers shortcut</bridgehead>
<para>
As with <option>channels</option>, there is a shortcut that only works with the
left channel:
<screen>mplayer <replaceable>filename</replaceable> -af pan=1:1</screen>
Since <option>pan</option> has only one channel of input (the other channel is
discarded), there is only one set with one suboption, which specifies that the
only channel gets 100% of itself.
</para>

<bridgehead>Example: downmixing 6-channel PCM</bridgehead>
<para>
<application>MPlayer</application>'s decoder for 6-channel PCM is not capable of
downmixing. Here is a way to downmix PCM using <option>pan</option>:
<orderedlist>
<listitem><para>
  The number of output channels is 2, so the first suboption is "2".
</para></listitem>
<listitem><para>
  With six input channels there will be six sets of options. Fortunately,
  since we only care about the output of the first two channels, we only need to
  make two sets; the remaining four sets can be omitted. Beware that not all
  multichannel audio files have the same channel order! This example
  demonstrates downmixing a file with the same channels as AC-3 5.1:
  <programlisting>
0 - front left
1 - front right
2 - rear left
3 - rear right
4 - center front
5 - subwoofer<!--
  --></programlisting>
  The first set of suboptions lists the percentages of the original volume, in
  order, which each output channel should receive from the
  front left channel: "1:0".
  The front right channel should go into the right output: "0:1".
  The same for the rear channels: "1:0" and "0:1".
  The center channel goes into both output channels with half volume:
  "0.5:0.5", and the subwoofer goes into both with full volume: "1:1".
</para></listitem>
</orderedlist>
Put all that together, for:
<screen>
mplayer <replaceable>6-channel.wav</replaceable> -af pan=2:1:0:0:1:1:0:0:1:0.5:0.5:1:1
</screen>
The percentages listed above are only a rough example. Feel free to tweak them.
</para>

<bridgehead>Example: Playing 5.1 audio on big speakers without a subwoofer</bridgehead>
<para>
If you have a huge pair of front speakers you may not want to waste any money on
buying a subwoofer for a complete 5.1 sound system. If you use
<option>-channels 5</option> to request that liba52 decode 5.1 audio in 5.0,
the subwoofer channel is simply discarded. If you want to distribute the
subwoofer channel yourself you need to downmix manually with
<option>pan</option>:
<orderedlist>
<listitem><para>
  Since <option>pan</option> needs to examine all six channels, specify
  <option>-channels 6</option> so liba52 decodes them all.
</para></listitem>
<listitem><para>
  <option>pan</option> outputs to only five channels, the first suboption is 5.
</para></listitem>
<listitem><para>
  Six input channels and five output channels means six sets of five suboptions.
  <itemizedlist spacing="compact">
  <listitem><para>
    The left front channel only replicates onto itself:
    "1:0:0:0:0"
  </para></listitem>
  <listitem><para>
    Same for the right front channel:
    "0:1:0:0:0"
  </para></listitem>
  <listitem><para>
    Same for the left rear channel:
    "0:0:1:0:0"
  </para></listitem>
  <listitem><para>
    And also the same for the right rear channel:
    "0:0:0:1:0"
  </para></listitem>
  <listitem><para>
    Center front, too:
    "0:0:0:0:1"
  </para></listitem>
  <listitem><para>
    And now we have to decide what to do with the subwoofer,
    e.g. half into front right and front left:
    "0.5:0.5:0:0:0"
  </para></listitem>
  </itemizedlist>
</para></listitem>
</orderedlist>
Combine all those options to get:
<screen>
mplayer <replaceable>dvd://1</replaceable> -channels 6 -af pan=5:1:0:0:0:0:0:1:0:0:0:0:0:1:0:0:0:0:0:1:0:0:0:0:0:1:0.5:0.5:0:0:0
</screen>
</para>
</sect2>
</sect1>

<!-- ********** -->

<sect1 id="advaudio-volume">
<title>Software Volume adjustment</title>

<para>
Some audio tracks are too quiet to be heard comfortably without amplification.
This becomes a problem when your audio equipment cannot amplify the signal for
you. The <option>-softvol</option> option directs
<application>MPlayer</application> to use an internal mixer. You can then use
the volume adjustment keys (by default <keycap>9</keycap> and
<keycap>0</keycap>) to reach much higher volume levels. Note that this does not
bypass your sound card's mixer; <application>MPlayer</application> only
amplifies the signal before sending it to your sound card.
The following example is a good start:
<screen>
mplayer <replaceable>quiet-file</replaceable> -softvol -softvol-max 300
</screen>
The <option>-softvol-max</option> option specifies the maximum allowable output
volume as a percentage of the
original volume. For example, <option>-softvol-max 200</option> would allow the
volume to be adjusted up to twice its original level.
It is safe to specify a large value with
<option>-softvol-max</option>; the higher volume will not be used until you
use the volume adjustment keys. The only disadvantage of a large value is that,
since <application>MPlayer</application> adjusts volume by a percentage of the
maximum, you will not have as precise control when using the volume adjustment
keys. Use a lower value with <option>-softvol-max</option> and/or specify
<option>-volstep 1</option> if you need higher precision.
</para>

<para>
The <option>-softvol</option> option works by controlling the
<option>volume</option> audio filter. If you want to play a file at a certain
volume from the beginning you can specify <option>volume</option> manually:
<screen>mplayer <replaceable>quiet-file</replaceable> -af volume=10</screen>
This will play the file with a ten decibel gain. Be careful when using the
<option>volume</option> filter - you could easily hurt your ears if you use
too high a value. Start low and work your way up gradually until you get a feel
for how much adjustment is required. Also, if you specify excessively high
values, <option>volume</option> may need to clip the signal to avoid sending
your sound card data that is outside the allowable range; this will result in
distorted audio.
</para>
</sect1>

<!-- ********** -->

<sect1 id="tv-input" xreflabel="TV input">
<title>TV input</title>

<para>
This section is about how to enable <emphasis role="bold">watching/grabbing
from V4L compatible TV tuner</emphasis>. See the man page for a description
of TV options and keyboard controls.
</para>

<sect2 id="tv-tips">
<title>Usage tips</title>

<para>
The full listing of the options is available on the manual page.
Here are just a few tips:

<itemizedlist>
<listitem><para>
  Make sure your tuner works with another TV software in Linux, for
  example <application>XawTV</application>.
</para></listitem>
<listitem><para>
  Use the <option>channels</option> option. An example:
  <screen>-tv channels=26-MTV1,23-TV2</screen>
  Explanation: Using this option, only the 26 and 23 channels will be usable,
  and there will be a nice OSD text upon channel switching, displaying the
  channel's name. Spaces in the channel name must be replaced by the
  "_" character.
</para></listitem>
<listitem><para>
  Choose some sane image dimensions. The dimensions of the resulting image
  should be divisible by 16.
</para></listitem>
<listitem>
  <para>
  If you capture the video with the vertical resolution higher than half
  of the full resolution (i.e. 288 for PAL or 240 for NTSC), then the
  'frames' you get will really be interleaved pairs of fields.
  Depending on what you want to do with the video you may leave it in
  this form, destructively deinterlace, or break the pairs apart into
  individual fields.
  </para>
  <para>
  Otherwise you'll get a movie which is distorted during
  fast-motion scenes and the bitrate controller will be probably even unable
  to retain the specified bitrate as the interlacing artifacts produce high
  amount of detail and thus consume lot of bandwidth. You can enable
  deinterlacing with <option>-vf pp=DEINT_TYPE</option>.
  Usually <option>pp=lb</option> does a good job, but it can be matter of
  personal preference.
  See other deinterlacing algorithms in the manual and give it a try.
  </para>
</listitem>
<listitem><para>
  Crop out the dead space. When you capture the video, the areas at the edges
  are usually black or contain some noise. These again consume lots of
  unnecessary bandwidth. More precisely it's not the black areas themselves
  but the sharp transitions between the black and the brighter video image
  which do but that's not important for now. Before you start capturing,
  adjust the arguments of the <option>crop</option> option so that all the
  crap at the margins is cropped out. Again, don't forget to keep the resulting
  dimensions sane.
</para></listitem>
<listitem><para>
  Watch out for CPU load. It shouldn't cross the 90% boundary for most of the
  time. If you have a large capture buffer, <application>MEncoder</application>
  can survive an overload for few seconds but nothing more. It's better to
  turn off the 3D OpenGL screensavers and similar stuff.
</para></listitem>
<listitem><para>
  Don't mess with the system clock. <application>MEncoder</application> uses the
  system clock for doing A/V sync. If you adjust the system clock (especially
  backwards in time), <application>MEncoder</application> gets confused and you
  will lose frames. This is an important issue if you are hooked to a network
  and run some time synchronization software like NTP. You have to turn NTP
  off during the capture process if you want to capture reliably.
</para></listitem>
<listitem><para>
  Don't change the <option>outfmt</option> unless you know what you are doing
  or your card/driver really doesn't support the default (YV12 colorspace).
  In the older versions of <application>MPlayer</application>/
  <application>MEncoder</application> it was necessary to specify the output
  format. This issue should be fixed in the current releases and
  <option>outfmt</option> isn't required anymore, and the default suits the
  most purposes. For example, if you are capturing into DivX using
  <systemitem class="library">libavcodec</systemitem> and specify
  <option>outfmt=RGB24</option> in order to increase the quality of the captured
  images, the captured image will be actually later converted back into YV12 so
  the only thing you achieve is a massive waste of CPU power.
</para></listitem>
<listitem><para>
  There are several ways of capturing audio. You can grab the sound either using
  your sound card via an external cable connection between video card and
  line-in, or using the built-in ADC in the bt878 chip. In the latter case, you
  have to load the <emphasis role="bold">btaudio</emphasis> driver. Read the
  <filename>linux/Documentation/sound/btaudio</filename> file (in the kernel
  tree, not <application>MPlayer</application>'s) for some instructions on using
  this driver.
</para></listitem>
<listitem><para>
  If <application>MEncoder</application> cannot open the audio device, make
  sure that it is really available. There can be some trouble with the sound
  servers like aRts (KDE) or ESD (GNOME). If you have a full duplex sound card
  (almost any decent card supports it today), and you are using KDE, try to
  check the "full duplex" option in the sound server preference menu.
</para></listitem>
</itemizedlist>
</para>
</sect2>

<sect2 id="tv-examples">
<title>Examples</title>

<informalexample><para>
Dummy output, to AAlib :)
<screen>mplayer -tv driver=dummy:width=640:height=480 -vo aa tv://</screen>
</para></informalexample>

<informalexample><para>
Input from standard V4L:
<screen>
mplayer -tv driver=v4l:width=640:height=480:outfmt=i420 -vc rawi420 -vo xv tv://
</screen>
</para></informalexample>

<informalexample><para>
A more sophisticated example. This makes <application>MEncoder</application>
capture the full PAL image, crop the margins, and deinterlace the picture
using a linear blend algorithm. Audio is compressed with a constant bitrate
of 64kbps, using LAME codec. This setup is suitable for capturing movies.
<screen>
mencoder -tv driver=v4l:width=768:height=576 -oac mp3lame -lameopts cbr:br=64\
    -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=900 \
    -vf crop=720:544:24:16,pp=lb -o <replaceable>output.avi</replaceable> tv://
</screen>
</para></informalexample>

<informalexample><para>
This will additionally rescale the image to 384x288 and compresses the
video with the bitrate of 350kbps in high quality mode. The vqmax option
looses the quantizer and allows the video compressor to actually reach so
low bitrate even at the expense of the quality. This can be used for
capturing long TV series, where the video quality isn't so important.
<screen>
mencoder -tv driver=v4l:width=768:height=576 \
    -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=350:vhq:vqmax=31:keyint=300 \
    -oac mp3lame -lameopts cbr:br=48 -sws 1 -o <replaceable>output.avi</replaceable>\
    -vf crop=720:540:24:18,pp=lb,scale=384:288 tv://
</screen>
It's also possible to specify smaller image dimensions in the
<option>-tv</option> option and omit the software scaling but this approach
uses the maximum available information and is a little more resistant to noise.
The bt8x8 chips can do the pixel averaging only in the horizontal direction due
to a hardware limitation.
</para></informalexample>
</sect2>
</sect1>

<!-- ********** -->

<sect1 id="tv-teletext">
<title>Teletext</title>

<para>
  Teletext is currently available only in <application>MPlayer</application>
  for v4l and v4l2 drivers.
</para>

<sect2 id="tv-teletext-implementation-notes">
<title>Implementation notes</title>

<para>
<application>MPlayer</application> supports regular text, graphics and navigation links.
Unfortunately, colored pages are not fully supported yet - all pages are shown as grayscaled.
Subtitle pages (also known as Closed Captions) are supported, too.
</para>

<para>
<application>MPlayer</application> starts caching all teletext pages upon
starting to receive TV input, so you do not need to wait until the requested page is loaded.
</para>

<para>
Note: Using teletext with <option>-vo xv</option> causes strange colors.
</para>
</sect2>

<sect2 id="tv-teletext-usage">
<title>Using teletext</title>

<para>
To enable teletext decoding you must specify the VBI device to get teletext data
from (usually <filename>/dev/vbi0</filename> for Linux). This can be done by specifying
<option>tdevice</option> in your configuration file, like shown below:
<screen>tv=tdevice=/dev/vbi0</screen>
</para>

<para>
You might need to specify the teletext language code for your country.
To list all available country codes use
<screen>tv=tdevice=/dev/vbi0:tlang=<replaceable>-1</replaceable></screen>
Here is an example for Russian:
<screen>tv=tdevice=/dev/vbi0:tlang=<replaceable>33</replaceable></screen>
</para>
</sect2>

</sect1>

<!-- ********** -->

<sect1 id="radio">
<title>Radio</title>

<para>
This section is about how to enable listening to radio from
a V4L-compatible radio tuner. See the man page for a
description of radio options and keyboard controls.
</para>

<!-- ********** -->

<sect2 id="radio-tips">
<title>Usage tips</title>

<para>
The full listing of the options is available in the manual page.
Here are just a few tips:

<itemizedlist>
<listitem><para>
  Make sure your tuner works with another radio software in Linux, for
  example <application>XawTV</application>.
</para></listitem>
<listitem><para>
  Use the <option>channels</option> option. An example:
  <screen>-radio channels=104.4-Sibir,103.9-Maximum</screen>
  Explanation: With this option, only the 104.4 and 103.9 radio stations
  will be usable. There will be a nice OSD text upon channel switching,
  displaying the channel's name. Spaces in the channel name must be
  replaced by the "_" character.
</para></listitem>
<listitem><para>
  There are several ways of capturing audio. You can grab the sound either using
  your sound card via an external cable connection between video card and
  line-in, or using the built-in ADC in the saa7134 chip. In the latter case,
  you have to load the <systemitem>saa7134-alsa</systemitem> or
  <systemitem>saa7134-oss</systemitem> driver.
</para></listitem>
<listitem><para>
  <application>MEncoder</application> cannot be used for audio capture,
  because it requires a video stream to work. So your can either use
  <application>arecord</application> from ALSA project or
  use <option>-ao pcm:file=file.wav</option>. In the latter case you
  will not hear any sound (unless you are using a line-in cable and
  have switched line-in mute off).
</para></listitem>
</itemizedlist>
</para>
</sect2>

<!-- ********** -->

<sect2 id="radio-examples">
<title>Examples</title>

<informalexample><para>
Input from standard V4L (using line-in cable, capture switched off):
<screen>mplayer radio://104.4</screen>
</para></informalexample>

<informalexample><para>
Input from standard V4L (using line-in cable, capture switched off,
V4Lv1 interface):
<screen>mplayer -radio driver=v4l radio://104.4</screen>
</para></informalexample>

<informalexample><para>
Playing second channel from channel list:
<screen>mplayer -radio channels=104.4=Sibir,103.9=Maximm radio://2</screen>
</para></informalexample>

<informalexample>
<para>
Passing sound over the PCI bus from the radio card's internal ADC.
In this example the tuner is used as a second sound card
(ALSA device hw:1,0). For saa7134-based cards either the
<systemitem>saa7134-alsa</systemitem> or <systemitem>saa7134-oss</systemitem>
module must be loaded.
<screen>
mplayer -rawaudio rate=32000 radio://2/capture \
    -radio adevice=hw=1.0:arate=32000:channels=104.4=Sibir,103.9=Maximm
</screen>
<note><para>
When using ALSA device names colons must be replaced
by equal signs, commas by periods.
</para></note>
</para>
</informalexample>
</sect2>

</sect1>
</chapter>
