[MPlayer-translations] r31966 - trunk/DOCS/xml/zh_CN/usage.xml

diego subversion at mplayerhq.hu
Tue Aug 17 13:39:37 CEST 2010 

Author: diego
Date: Tue Aug 17 13:39:37 2010
New Revision: 31966

Log:
Add copy of English usage.xml file to Chinese translation.
This will be useful to merge other parts of the Chinese translation into it.

Added:
   trunk/DOCS/xml/zh_CN/usage.xml

Added: trunk/DOCS/xml/zh_CN/usage.xml
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ trunk/DOCS/xml/zh_CN/usage.xml	Tue Aug 17 13:39:37 2010	(r31966)
@@ -0,0 +1,1123 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- $Revision: 31940 $ -->
+<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>
+
+
+<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
+
+
+<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>
+
+
+<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
+
+
+<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>
+
+
+<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
+
+
+<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>
+
+
+<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
+
+
+<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>
+
+
+<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
+
+
+<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>
+</chapter>

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