<?xml version="1.0" encoding="utf-8"?>

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd"
[
<!ENTITY product "mkvmerge">
<!ENTITY version "3.0.0">
<!ENTITY date "December 2009">

<!ENTITY mkvmerge "<citerefentry><refentrytitle>mkvmerge</refentrytitle><manvolnum>1</manvolnum></citerefentry>">
<!ENTITY mkvinfo "<citerefentry><refentrytitle>mkvinfo</refentrytitle><manvolnum>1</manvolnum></citerefentry>">
<!ENTITY mkvextract "<citerefentry><refentrytitle>mkvextract</refentrytitle><manvolnum>1</manvolnum></citerefentry>">
<!ENTITY mkvpropedit "<citerefentry><refentrytitle>mkvpropedit</refentrytitle><manvolnum>1</manvolnum></citerefentry>">
<!ENTITY mmg "<citerefentry><refentrytitle>mmg</refentrytitle><manvolnum>1</manvolnum></citerefentry>">

<!ENTITY matroska "<productname>Matroska</productname>">
<!ENTITY oggvorbis "<productname>OggVorbis</productname>">
<!ENTITY xml "<abbrev>XML</abbrev>">

]>

<refentry lang="en" id="mkvmerge">
 <refentryinfo>
  <productname>&product;</productname>
  <date>&date;</date>
  <authorgroup>
   <author>
    <contrib>Developer</contrib>
    <firstname>Moritz</firstname>
    <surname>Bunkus</surname>
    <email>moritz@bunkus.org</email>
   </author>
  </authorgroup>
 </refentryinfo>
 <refmeta>
  <refentrytitle>&product;</refentrytitle>
  <manvolnum>1</manvolnum>
  <refmiscinfo class="version">&version;</refmiscinfo>
  <refmiscinfo class="date">&date;</refmiscinfo>
  <refmiscinfo class="source">MkvToolNix</refmiscinfo>
  <refmiscinfo class="manual">User Commands</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>&product;</refname>
  <refpurpose>Merge multimedia streams into a &matroska; file</refpurpose>
 </refnamediv>

 <refsynopsisdiv id="mkvmerge.synopsis">
  <title>Synopsis</title>
  <cmdsynopsis>
   <command>mkvmerge</command>
   <arg>global options</arg>
   <arg choice="req">-o out</arg>
   <arg>options1</arg>
   <arg choice="req">file1</arg>
   <arg>
    <arg>options2</arg>
    <arg choice="req">file2</arg>
   </arg>
   <arg>@optionsfile</arg>
  </cmdsynopsis>
 </refsynopsisdiv>

 <refsect1 id="mkvmerge.description">
  <title>Description</title>
  <para>
   This program takes the input from several media files and joins their streams (all of them or just a selection) into
   a &matroska; file; see <ulink url="http://www.matroska.org/">the &matroska; website</ulink>.
  </para>

  <para>
   Global options:
  </para>

  <variablelist>
   <varlistentry>
    <term><option>-v</option>, <option>--verbose</option></term>
    <listitem>
     <para>Increase verbosity.</para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-q</option>, <option>--quiet</option></term>
    <listitem>
     <para>Suppress status output.</para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-o</option>, <option>--out</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>Write to the file <parameter>file-name</parameter>.  If splitting is used then this parameter is treated a bit differently.  See
     the explanation for the <link linkend="mkvmerge.description.split"><option>--split</option></link> option for details.</para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.title">
    <term><option>--title</option> <parameter>title</parameter></term>
    <listitem>
     <para>Sets the general title for the output file, e.g. the movie name.</para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.tags">
    <term><option>--tags</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>Read global tags from the &xml; file <parameter>file-name</parameter>. See the section about tags below for
     details.</para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--default-language</option> <parameter>language-code</parameter></term>
    <listitem>
     <para>Sets the default language code that will be used for all tracks unless overwritten with the <link
     linkend="mkvmerge.description.language"><option>--language</option></link> option. The default language code is
     '<literal>und</literal>' for 'undefined'.</para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Chapter and tag handling: (global options)
  </para>

  <variablelist>
   <varlistentry>
    <term><option>--chapter-language</option> <parameter>language-code</parameter></term>
    <listitem>
     <para>
      Sets the ISO639-2 language code that is written for each chapter entry.  Defaults to '<literal>eng</literal>'.  See the section about
      <link linkend="mkvmerge.chapters">chapters</link> below for details.
     </para>

     <para>
      This option can be used both for simple chapter files and for source files that contain chapters but no information about the
      chapters' language, e.g. MP4 and OGM files.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.chapter_charset">
    <term><option>--chapter-charset</option> <parameter>character-set</parameter></term>
    <listitem>
     <para>
      Sets the character set that is used for the conversion to UTF-8 for simple chapter files. See the section about <link
      linkend="mkvmerge.text_files_and_charsets"> text files and character sets</link> for an explanation how &mkvmerge; converts between
      character sets.
     </para>

     <para>
      This switch does also apply to chapters that are copied from certain container types, e.g. Ogg/OGM and MP4 files.
      See the section about chapters below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--cue-chapter-name-format</option> <parameter>format</parameter></term>
    <listitem>
     <para>
      &mkvmerge; supports reading <abbrev>CUE</abbrev> sheets for audio files as the input for chapters. <abbrev>CUE</abbrev> sheets usually
      contain the entries <varname>PERFORMER</varname> and <varname>TITLE</varname> for each index entry. &mkvmerge; uses these two strings
      in order to construct the chapter name. With this option the format used for this name can be set.
     </para>

     <para>
      If this option is not given then &mkvmerge; defaults to the format '<code>%p - %t</code>' (the performer, followed by a space, a dash,
      another space and the title).
     </para>

     <para>
      If the format is given then everything except the following meta characters is copied as-is, and the meta
      characters are replaced like this:
     </para>

     <itemizedlist>
      <listitem>
       <para><parameter>%p</parameter> is replaced by the current entry's <varname>PERFORMER</varname> string,</para>
      </listitem>
      <listitem>
       <para><parameter>%t</parameter> is replaced by the current entry's <varname>TITLE</varname> string,</para>
      </listitem>
      <listitem>
       <para><parameter>%n</parameter> is replaced by the current track number and</para>
      </listitem>
      <listitem>
       <para><parameter>%N</parameter> is replaced by the current track number padded with a leading zero if
       it is &lt; 10.</para>
      </listitem>
     </itemizedlist>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--chapters</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>
      Read chapter information from the file <parameter>file-name</parameter>. See the section about <link
      linkend="mkvmerge.chapters">chapters</link> below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.global_tags">
    <term><option>--global-tags</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>
      Read global tags from the file <parameter>file-name</parameter>. See the section about <link linkend="mkvmerge.tags">tags</link> below
      for details.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   General output control (advanced global options):
  </para>

  <variablelist>
   <varlistentry>
    <term><option>--track-order</option> <parameter>FID1:TID1,FID2:TID2,...</parameter></term>
    <listitem>
     <para>
      This option changes the order in which the tracks for an input file are created. The argument is a comma separated list of pairs
      IDs. Each pair contains first the file ID (<parameter>FID1</parameter>) which is simply the number of the file on the command line
      starting at 0. The second is a track ID (<parameter>TID1</parameter>) from that file.  If some track IDs are omitted then those tracks
      are created after the ones given with this option have been created.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--cluster-length</option> <parameter>spec</parameter></term>
    <listitem>
     <para>
      Limit the number of data blocks or the duration of data in each cluster. The <parameter>spec</parameter> parameter can either be a
      number <parameter>n</parameter> without a unit or a number <parameter>d</parameter> postfixed with '<literal>ms</literal>'.
     </para>

     <para>
      If no unit is used then &mkvmerge; will put at most <parameter>n</parameter> data blocks into each cluster. The maximum number of
      blocks is 65535.
     </para>

     <para>
      If the number <parameter>n</parameter> is postfixed with '<literal>ms</literal>' then &mkvmerge; puts at most <parameter>d</parameter>
      milliseconds of data into each cluster. The minimum for <parameter>d</parameter> is '<literal>100ms</literal>', and the maximum is
      '<literal>32000ms</literal>'.
     </para>

     <para>
      &mkvmerge; defaults to putting at most 65535 data blocks and 2000ms of data into a cluster.
     </para>

     <para>
      Programs trying to find a certain frame can only seek directly to a cluster and have to read the whole cluster afterwards. Therefore
      creating larger clusters may lead to imprecise or slow seeking.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.no_cues">
    <term><option>--no-cues</option></term>
    <listitem>
     <para>
      Tells &mkvmerge; not to create and write the cue data which can be compared to an index in an AVI. &matroska; files can be played back
      without the cue data, but seeking will probably be imprecise and slower. Use this only if you're really desperate for space or for
      testing purposes. See also option <link linkend="mkvmerge.description.cues"><option>--cues</option></link> which can be specified for
      each input file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--no-clusters-in-meta-seek</option></term>
    <listitem>
     <para>
      Tells &mkvmerge; not to create a meta seek element at the end of the file containing all clusters. See also the section about the
      <link linkend="mkvmerge.file_layout">&matroska; file layout</link>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--disable-lacing</option></term>
    <listitem>
     <para>
      Disables lacing for all tracks. This will increase the file's size, especially if there are many audio tracks. This option is not
      intended for everyday use.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--enable-durations</option></term>
    <listitem>
     <para>
      Write durations for all blocks. This will increase file size and does not offer any additional value for players at the moment.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--timecode-scale</option> <parameter>factor</parameter></term>
    <listitem>
     <para>
      Forces the timecode scale factor to <parameter>factor</parameter>. Valid values are in the range
      <constant>1000</constant>..<constant>10000000</constant> or the special value <constant>-1</constant>.
     </para>

     <para>
      Normally &mkvmerge; will use a value of <constant>1000000</constant> which means that timecodes and durations will have a precision of
      1ms. For files that will not contain a video track but at least one audio track &mkvmerge; will automatically chose a timecode scale
      factor so that all timecodes and durations have a precision of one audio sample. This causes bigger overhead but allows precise
      seeking and extraction.
     </para>

     <para>
      If the special value <constant>-1</constant> is used then &mkvmerge; will use sample precision even if a video track is present.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   File splitting, linking and appending (more global options):
  </para>

  <variablelist>
   <varlistentry id="mkvmerge.description.split">
    <term><option>--split</option> <parameter>specification</parameter></term>

    <listitem>
     <para>
      Splits the output file after a given size or a given time.  Please note that tracks can only be split right before a key frame.  Due
      to buffering &mkvmerge; will split right before the next key frame after the split point has been reached.  Therefore the split point
      may be a bit off from what the user has specified.
     </para>

     <para>
      At the moment &mkvmerge; supports three different modes.
     </para>

     <orderedlist>
      <listitem>
       <para>
        Splitting by size.
       </para>

       <para>
        Syntax: <option>--split</option> <optional>size:</optional><parameter>d</parameter><optional>k|m|g</optional>
       </para>

       <para>
        Examples: <code>--split size:700m</code> or <code>--split 150000000</code>
       </para>

       <para>
        The parameter <parameter>d</parameter> may end with '<literal>k</literal>', '<literal>m</literal>' or '<literal>g</literal>' to
        indicate that the size is in KB, MB or GB respectively.  Otherwise a size in Bytes is assumed.  After the current output file has
        reached this size limit a new one will be started.
       </para>

       <para>
        The '<literal>size:</literal>' prefix may be omitted for compatibility reasons.
       </para>
      </listitem>

      <listitem>
       <para>
        Splitting after a duration.
       </para>

       <para>
        Syntax: <option>--split</option> <optional>duration:</optional><parameter>HH:MM:SS.nnnnnnnnn</parameter>|<parameter>d</parameter>s
       </para>

       <para>
        Examples: <code>--split duration:00:60:00.000</code> or <code>--split 3600s</code>
       </para>

       <para>
        The paramter must either have the form <parameter>HH:MM:SS.nnnnnnnnn</parameter> for specifying the duration in up to nano-second
        precision or be a number <parameter>d</parameter> followed by the letter '<literal>s</literal>' for the duration in
        seconds. <parameter>HH</parameter> is the number of hours, <parameter>MM</parameter> the number of minutes,
        <parameter>SS</parameter> the number of seconds and <parameter>nnnnnnnnn</parameter> the number of nanoseconds.  Both the number of
        hours and the number of nanoseconds can be omitted.  There can be up to nine digits after the decimal point.  After the duration of
        the contents in the current output has reached this limit a new output file will be started.
       </para>

       <para>
        The '<literal>duration:</literal>' prefix may be omitted for compatibility reasons.
       </para>
      </listitem>

      <listitem>
       <para>
        Splitting after specific timecodes.
       </para>

       <para>
        Syntax: <option>--split</option> timecodes:<parameter>A</parameter><optional>,<parameter>B</parameter><optional>,<parameter>C</parameter>...</optional></optional>
       </para>

       <para>
        Example: <code>--split timecodes:00:45:00.000,01:20:00.250,6300s</code>
       </para>

       <para>
        The parameters <parameter>A</parameter>, <parameter>B</parameter>, <parameter>c</parameter> etc must all have the same format as the
        ones used for the duration (see above). The list of timecodes is separated by commas.  After the input stream has reached the
        current split point's timecode a new file is created. Then the next split point given in this list is used.
       </para>

       <para>
        The '<literal>timecodes:</literal>' prefix must not be omitted.
       </para>

       <para>
        For this splitting mode the output filename is treated differently than for the normal operation. It may contain a
        <function>printf</function> like expression '<literal>%d</literal>' including an optional field width,
        e.g. '<literal>%02d</literal>'. If it does then the current file number will be formatted appropriately and inserted at that point
        in the filename.  If there is no such pattern then a pattern of '<literal>-%03d</literal>' is assumed right before the file's
        extension: '<literal>-o output.mkv</literal>' would result in '<literal>output-001.mkv</literal>' and so on. If there's no extension
        then '<literal>-%03d</literal>' will be appended to the name.
       </para>
      </listitem>
     </orderedlist>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.link">
    <term><option>--link</option></term>
    <listitem>
     <para>
      Link files to one another when splitting the output file. See the section on <link linkend="mkvmerge.file_linking">file linking</link>
      below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--link-to-previous</option> <parameter>segment-UID</parameter></term>
    <listitem>
     <para>
      Links the first output file to the segment with the segment UID given by the <parameter>segment-UID</parameter> parameter. See the
      section on <link linkend="mkvmerge.file_linking">file linking</link> below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--link-to-next</option> <parameter>segment-UID</parameter></term>
    <listitem>
     <para>
      Links the last output file to the segment with the segment UID given by the <parameter>segment-UID</parameter> parameter. See the
      section on <link linkend="mkvmerge.file_linking">file linking</link> below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--append-mode</option> <parameter>mode</parameter></term>
    <listitem>
     <para>
      Determines how timecodes are calculated when appending files.  The parameter <parameter>mode</parameter> can have two values:
      '<literal>file</literal>' which is also the default and '<literal>track</literal>'.
     </para>

     <para>
      When mkvmerge appends a track (called '<literal>track2_1</literal>' from now on) from a second file (called
      '<literal>file2</literal>') to a track (called '<literal>track1_1</literal>') from the first file (called '<literal>file1</literal>')
      then it has to offset all timecodes for '<literal>track2_1</literal>' by an amount.  For '<literal>file</literal>' mode this amount is
      the highest timecode encountered in '<literal>file1</literal>' even if that timecode was from a different track than
      '<literal>track1_1</literal>'. In track mode the offset is the highest timecode of '<literal>track1_1</literal>'.
     </para>

     <para>
      Unfortunately mkvmerge cannot detect which mode to use reliably. Therefore it defaults to '<literal>file</literal>'
      mode. '<literal>file</literal>' mode usually works better for files that have been created independently of each other; e.g. when
      appending <abbrev>AVI</abbrev> or <abbrev>MP4</abbrev> files. '<literal>track</literal>' mode may work better for sources that are
      essentially just parts of one big file, e.g. for <abbrev>VOB</abbrev> and <abbrev>EVO</abbrev> files.
     </para>

     <para>
      Subtitle tracks are always treated as if '<literal>file</literal>' mode were active even if '<literal>track</literal>' mode actually
      is.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--append-to</option> <parameter>SFID1:STID1:DFID1:DTID1<optional>,...</optional></parameter></term>
    <listitem>
     <para>
      This option controls to which track another track is appended.  Each spec contains four IDs: a file ID, a track ID, a second file ID
      and a second track ID.  The first pair, "source file ID" and "source track ID", identifies the track that is to be appended.  The
      second pair, "destination file ID" and "destination track ID", identifies the track the first one is appended to.
     </para>

     <para>
      If this option has been omitted then a standard mapping is used.  This standard mapping appends each track from the current file to a
      track from the previous file with the same track ID.  This allows for easy appending if a movie has been split into two parts and both
      file have the same number of tracks and track IDs with the command <command>mkvmerge -o output.mkv part1.mkv +part2.mkv</command>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>+</option></term>
    <listitem>
     <para>
      A single '+' causes the next file to be appended instead of added. The '+' can also be put in front of the next file name. Therefore
      the following two commands are equivalent:
     </para>

     <screen>
$ mkvmerge -o full.mkv file1.mkv + file2.mkv
$ mkvmerge -o full.mkv file1.mkv +file2.mkv
     </screen>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Attachment support (more global options):
  </para>

  <variablelist>
   <varlistentry  id="mkvmerge.description.attachment_description">
    <term><option>--attachment-description</option> <parameter>description</parameter></term>
    <listitem>
     <para>
      Plain text description of the following attachment. Applies to the next <link
      linkend="mkvmerge.description.attach_file"><option>--attach-file</option></link> or <option>--attach-file-once</option> option.

     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--attachment-mime-type</option> <parameter>MIME type</parameter></term>
    <listitem>
     <para>
      <abbrev >MIME</abbrev> type of the following attachment. Applies to the next <link
      linkend="mkvmerge.description.attach_file"><option>--attach-file</option></link> or <link
      linkend="mkvmerge.description.attach_file"><option>--attach-file-once</option></link> option.  A list of officially recognized
      <abbrev>MIME</abbrev> types can be found e.g. at <ulink url="http://www.iana.org/assignments/media-types/">the IANA
      homepage</ulink>. The <abbrev>MIME</abbrev> type is mandatory for an attachment.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--attachment-name</option> <parameter>name</parameter></term>
    <listitem>
     <para>
      Sets the name that will be stored in the output file for this attachment.  If this option is not given then the name will be derived
      from the file name of the attachment as given with the <link
      linkend="mkvmerge.description.attach_file"><option>--attach-file</option></link> or the <link
      linkend="mkvmerge.description.attach_file"><option>--attach-file-once</option></link> option.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.attach_file">
    <term>
     <option>--attach-file</option> <parameter>file-name</parameter>,
     <option>--attach-file-once</option> <parameter>file-name</parameter>
    </term>
    <listitem>
     <para>
      Creates a file attachment inside the &matroska; file. The <abbrev>MIME</abbrev> type must have been set before this option can used. The
      difference between the two forms is that during splitting the files attached with <option>--attach-file</option> are attached to all
      output files while the ones attached with <option>--attach-file-once</option> are only attached to the first file created.  If
      splitting is not used then both do the same.
     </para>

     <para>
      &mkvextract; can be used to extract attached files from a &matroska; file.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Options that can be used for each input file:
  </para>

  <variablelist>
   <varlistentry>
    <term><option>-a</option>, <option>--audio-tracks</option> <parameter>n,m,...</parameter></term>
    <listitem>
     <para>
      Copy the audio tracks <parameter>n</parameter>, <parameter>m</parameter> etc. The numbers are track IDs which can be obtained with the
      <link linkend="mkvmerge.description.identify"><option>--identify</option></link> switch. They're not simply the track numbers (see
      section <link linkend="mkvmerge.track_ids">track IDs</link>). Default: copy all audio tracks.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-d</option>, <option>--video-tracks</option> <parameter>n,m,...</parameter></term>
    <listitem>
     <para>
      Copy the video tracks <parameter>n</parameter>, <parameter>m</parameter> etc. The numbers are track IDs which can be obtained with the
      <link linkend="mkvmerge.description.identify"><option>--identify</option></link> switch. They're not simply the track numbers (see
      section <link linkend="mkvmerge.track_ids">track IDs</link>). Default: copy all video tracks.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-s</option>, <option>--subtitle-tracks</option> <parameter>n,m,...</parameter></term>
    <listitem>
     <para>
      Copy the subtitle tracks <parameter>n</parameter>, <parameter>m</parameter> etc. The numbers are track IDs which can be obtained with
      the <link linkend="mkvmerge.description.identify"><option>--identify</option></link> switch. They're not simply the track numbers (see
      section <link linkend="mkvmerge.track_ids">track IDs</link>). Default: copy all subtitle tracks.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-b</option>, <option>--button-tracks</option> <parameter>n,m,...</parameter></term>
    <listitem>
     <para>
      Copy the button tracks <parameter>n</parameter>, <parameter>m</parameter> etc. The numbers are track IDs which can be obtained with
      the <link linkend="mkvmerge.description.identify"><option>--identify</option></link> switch. They're not simply the track numbers (see
      section <link linkend="mkvmerge.track_ids">track IDs</link>). Default: copy all button tracks.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--track-tags</option> <parameter>n,m,...</parameter></term>
    <listitem>
     <para>
      Copy the tags for tracks <parameter>n</parameter>, <parameter>m</parameter> etc.  The numbers are track IDs which can be obtained with
      the <link linkend="mkvmerge.description.identify"><option>--identify</option></link> switch (see section <link
      linkend="mkvmerge.track_ids">track IDs</link>).  They're not simply the track numbers.  Default: copy tags for all tracks.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.attachments">
    <term><option>-m</option>, <option>--attachments</option> <parameter>n<optional>:all|first</optional>,m<optional>:all|first</optional>,...</parameter></term>
    <listitem>
     <para>
      Copy the attachments with the IDs <parameter>n</parameter>, <parameter>m</parameter> etc to all or only the first output file. Each ID
      can be followed by either '<literal>:all</literal>' (which is the default if neither is entered) or '<literal>:first</literal>'. If
      splitting is active then those attachments whose IDs are specified with '<literal>:all</literal>' are copied to all of the resulting
      output files while the others are only copied into the first output file. If splitting is not active then both variants have the same
      effect.
     </para>

     <para>
      The default is to copy all attachments to all output files.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-A</option>, <option>--no-audio</option></term>
    <listitem>
     <para>
      Don't copy any audio track from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-D</option>, <option>--no-video</option></term>
    <listitem>
     <para>
      Don't copy any video track from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-S</option>, <option>--no-subtitles</option></term>
    <listitem>
     <para>
      Don't copy any subtitle track from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-B</option>, <option>--no-buttons</option></term>
    <listitem>
     <para>
      Don't copy any button track from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-T</option>, <option>--no-track-tags</option></term>
    <listitem>
     <para>
      Don't copy any track specific tags from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.no_chapters">
    <term><option>--no-chapters</option></term>
    <listitem>
     <para>
      Don't copy chapters from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.no_attachments">
    <term><option>-M</option>, <option>--no-attachments</option></term>
    <listitem>
     <para>
      Don't copy attachments from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--no-global-tags</option></term>
    <listitem>
     <para>
      Don't copy global tags from this file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--chapter-charset</option> <parameter>character-set</parameter></term>
    <listitem>
     <para>
      Sets the charset that is used for the conversion to UTF-8 for chapter information contained in the source file. See the section about
      <link linkend="mkvmerge.text_files_and_charsets"> text files and character sets</link> for an explanation how &mkvmerge; converts
      between character sets.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--chapter-language</option> <parameter>language-code</parameter></term>
    <listitem>
     <para>
      Sets the ISO639-2 language code that is written for each chapter entry.  This option can be used for source files that contain
      chapters but no information about the chapters' languages, e.g. for MP4 and OGM files.
     </para>
    </listitem>
  </varlistentry>

   <varlistentry>
    <term><option>-y</option>, <option>--sync</option> <parameter>TID:d<optional>,o<optional>/p</optional></optional></parameter></term>
    <listitem>
     <para>
      Adjust the timecodes of the track with the id <parameter>TID</parameter> by <parameter>d</parameter> ms. The track IDs are the same as
      the ones given with <link linkend="mkvmerge.description.identify"><option>--identify</option></link> (see section <link
      linkend="mkvmerge.track_ids">track IDs</link>).
     </para>

     <para>
      <parameter>o</parameter>/<parameter>p</parameter>: adjust the timestamps by <parameter>o</parameter>/<parameter>p</parameter> to fix
      linear drifts. <parameter>p</parameter> defaults to 1 if omitted. Both <parameter>o</parameter> and <parameter>p</parameter> can be
      floating point numbers.
     </para>

     <para>
      Defaults: no manual sync correction (which is the same as <parameter>d</parameter> = <constant>0</constant> and
      <parameter>o</parameter>/<parameter>p</parameter> = <constant>1.0</constant>).
     </para>

     <para>
      This option can be used multiple times for an input file applying to several tracks by selecting different track IDs each time.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.cues">
    <term><option>--cues</option> <parameter>TID:none|iframes|all</parameter></term>
    <listitem>
     <para>
      Controls for which tracks cue (index) entries are created for the given track (see section <link linkend="mkvmerge.track_ids">track
      IDs</link>). '<literal>none</literal>' inhibits the creation of cue entries.  For '<literal>iframes</literal>' only blocks with
      no backward or forward references ( = I frames in video tracks) are put into the cue sheet. '<literal>all</literal>' causes
      &mkvmerge; to create cue entries for all blocks which will make the file very big.
     </para>

     <para>
      The default is '<literal>iframes</literal>' for video tracks and '<literal>none</literal>' for all others.  See also option <link
      linkend="mkvmerge.description.no_cues"><option>--no-cues</option></link> which inhibits the creation of cue entries regardless of the
      <option>--cues</option> options used.
     </para>

     <para>
      This option can be used multiple times for an input file applying to several tracks by selecting different track IDs each time.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--default-track</option> <parameter>TID<optional>:bool</optional></parameter></term>
    <listitem>
     <para>
      Sets the 'default' flag for the given track (see section <link linkend="mkvmerge.track_ids">track IDs</link>) if the optional argument
      <parameter>bool</parameter> is not present.  If the user does not explicitly select a track himself then the player should prefer the
      track that has his 'default' flag set. Only one track of each kind (audio, video, subtitles, buttons) can have his 'default' flag set.
      If the user wants no track to have the default track flag set then he has to set <parameter>bool</parameter> to <constant>0</constant>
      for all tracks.
     </para>

     <para>
      This option can be used multiple times for an input file applying to several tracks by selecting different track IDs each time.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--blockadd</option> <parameter>TID:level</parameter></term>
    <listitem>
     <para>
      Keep only the <classname>BlockAdditions</classname> up to the level <parameter>level</parameter> for the given track.  The default is
      to keep all levels.  This option only affects certain kinds of codecs like WAVPACK4.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.track_name">
    <term><option>--track-name</option> <parameter>TID:name</parameter></term>
    <listitem>
     <para>
      Sets the track name for the given track (see section <link linkend="mkvmerge.track_ids">track IDs</link>) to
      <parameter>name</parameter>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.language">
    <term><option>--language</option> <parameter>TID:language</parameter></term>
    <listitem>
     <para>
      Sets the language for the given track (see section <link linkend="mkvmerge.track_ids">track IDs</link>). Both ISO639-2 language codes
      and ISO639-1 country codes are allowed. The country codes will be converted to language codes automatically.  All languages including
      their ISO639-2 codes can be listed with the <link
      linkend="mkvmerge.description.list_languages"><option>--list-languages</option></link> option.
     </para>

     <para>
      This option can be used multiple times for an input file applying to several tracks by selecting different track IDs each time.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-t</option>, <option>--tags</option> <parameter>TID:file-name</parameter></term>
    <listitem>
     <para>
      Read tags for the track with the number <parameter>TID</parameter> from the file <parameter>file-name</parameter>. See the section
      about <link linkend="mkvmerge.tags">tags</link> below for details.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--aac-is-sbr</option> <parameter>TID<optional>:0|1</optional></parameter></term>
    <listitem>
     <para>
      Tells &mkvmerge; that the track with the ID <parameter>TID</parameter> is <abbrev>SBR AAC</abbrev> (also known as
      <abbrev>HE-AAC</abbrev> or <abbrev>AAC+</abbrev>). This options is needed if a) the source file is an <abbrev>AAC</abbrev> file
      (<emphasis>not</emphasis> for a &matroska; file) and b) the <abbrev>AAC</abbrev> file contains <abbrev>SBR AAC</abbrev> data.  The
      reason for this switch is that it is technically impossible to automatically tell normal <abbrev>AAC</abbrev> data from <abbrev>SBR
      AAC</abbrev> data without decoding a complete <abbrev>AAC</abbrev> frame. As there are several patent issues with <abbrev>AAC</abbrev>
      decoders &mkvmerge; will never contain this decoding stage. So for <abbrev>SBR AAC</abbrev> files this switch is mandatory. The
      resulting file might not play back correctly or even not at all if the switch was omitted.
     </para>

     <para>
      If the source file is a &matroska; file then the <classname>CodecID</classname> should be enough to detect <abbrev>SBR
      AAC</abbrev>. However, if the <classname>CodecID</classname> is wrong then this switch can be used to correct that.
     </para>

     <para>
      If mkvmerge wrongfully detects that an <abbrev>AAC</abbrev> file is <abbrev>SBR</abbrev> then you can add
      '<literal>:0</literal>' to the track ID.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--timecodes</option> <parameter>TID:file-name</parameter></term>
    <listitem>
     <para>
      Read the timecodes to be used for the specific track ID from <parameter>file-name</parameter>.  These timecodes forcefully override
      the timecodes that &mkvmerge; normally calculates. Read the section about <link linkend="mkvmerge.external_timecode_files">external
      timecode files</link>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--default-duration</option> <parameter>TID:x</parameter></term>
    <listitem>
     <para>
      Forces the default duration of a given track to the specified value.  Also modifies the track's timecodes to match the default
      duration.  The argument <parameter>x</parameter> must be postfixed with '<literal>s</literal>', '<literal>ms</literal>',
      '<literal>us</literal>', '<literal>ns</literal>' or '<literal>fps</literal>' to specify the default duration in seconds, milliseconds,
      microseconds, nanoseconds or 'frames per second' respectively.  The number <parameter>x</parameter> itself can be a floating point
      number or a fraction.
     </para>

     <para>
      If the default duration is not forced then mkvmerge will try to derive the track's default duration from the container and/or codec
      used.  One case in which this option is of use is when adding <foreignphrase>AVC/h.264</foreignphrase> elementary streams because
      these do not contain information about their number of frames or a default duration for each frame.  For such files &mkvmerge; will
      assume a default duration of '<literal>25fps</literal>' unless overridden.
     </para>

     <para>
      This option can also be used to change the <abbrev>FPS</abbrev> of video tracks without having to use an external timecode file.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--nalu-size-length</option> <parameter>TID:n</parameter></term>
    <listitem>
     <para>
      Forces the <abbrev>NALU</abbrev> size length to <parameter>n</parameter> bytes.  This parameter is only used if the
      <foreignphrase>AVC/h.264</foreignphrase> elementary stream packetizer is used.  If left out it defaults to 4 bytes, but there are
      files that contain frames or slices that are a4ll smaller than 65536 bytes.  For such files you can use this parameter and decrease
      the size to 2.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Options that only apply to video tracks:
  </para>

  <variablelist>
   <varlistentry>
    <term><option>-f</option>, <option>--fourcc</option> <parameter>TID:FourCC</parameter></term>
    <listitem>
     <para>
      Forces the <classname>FourCC</classname> to the specified value. Works only for video tracks in the '<foreignphrase>MS compatibility
      mode</foreignphrase>'.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.display_dimensions">
    <term><option>--display-dimensions</option> <parameter>TID:widthxheight</parameter></term>
    <listitem>
     <para>
      &matroska; files contain two values that set the display properties that a player should scale the image on playback to: display width
      and display height.  These values can be set with this option, e.g. '<literal>1:640x480</literal>'.
     </para>

     <para>
      Another way to specify the values is to use the <link
      linkend="mkvmerge.description.aspect_ratio"><option>--aspect-ratio</option></link> or the <link
      linkend="mkvmerge.description.aspect_ratio_factor"><option>--aspect-ratio-factor</option></link> option (see below).  These options
      are mutually exclusive.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.aspect_ratio">
    <term><option>--aspect-ratio</option> <parameter>TID:ratio|width/height</parameter></term>
    <listitem>
     <para>
      &matroska; files contain two values that set the display properties that a player should scale the image on playback to: display width
      and display height.  With this option &mkvmerge; will automatically calculate the display width and display height based on the
      image's original width and height and the aspect ratio given with this option.  The ratio can be given either as a floating point
      number <parameter>ratio</parameter> or as a fraction '<parameter>width</parameter>/<parameter>height</parameter>',
      e.g. '<literal>16/9</literal>'.
     </para>

     <para>
      Another way to specify the values is to use the <link
      linkend="mkvmerge.description.aspect_ratio_factor"><option>--aspect-ratio-factor</option></link> or <link
      linkend="mkvmerge.description.display_dimensions"><option>--display-dimensions</option></link> options (see above and below). These
      options are mutually exclusive.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.aspect_ratio_factor">
    <term><option>--aspect-ratio-factor</option> <parameter>TID:factor|n/d</parameter></term>
    <listitem>
     <para>
      Another way to set the aspect ratio is to specify a <parameter>factor</parameter>. The original aspect ratio is first multiplied with
      this <parameter>factor</parameter> and used as the target aspect ratio afterwards.
     </para>

     <para>
      Another way to specify the values is to use the <link
      linkend="mkvmerge.description.aspect_ratio"><option>--aspect-ratio</option></link> or <link
      linkend="mkvmerge.description.display_dimensions"><option>--display-dimensions</option></link> options (see above). These options are
      mutually exclusive.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--cropping</option> <parameter>TID:left,top,right,bottom</parameter></term>
    <listitem>
     <para>
      Sets the pixel cropping parameters of a video track to the given values.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--stereo-mode</option> <parameter>TID:n|keyword</parameter></term>
    <listitem>
     <para>
      Sets the stereo mode for the video track with the track ID <parameter>TID</parameter>.  The mode can either be a number
      <parameter>n</parameter> between <constant>0</constant> and <constant>3</constant> or one of the keywords '<literal>none</literal>'
      (same as <parameter>n</parameter>=<constant>0</constant>), '<literal>right</literal>' (same as
      <parameter>n</parameter>=<constant>1</constant>), '<literal>left</literal>' (same as <parameter>n</parameter>=<constant>2</constant>)
      or '<literal>both</literal>' (same as <parameter>n</parameter>=<constant>3</constant>).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.compression">
    <term><option>--compression</option> <parameter>TID:method</parameter></term>
    <listitem>
     <para>
      Selects the compression method to be used for the VobSub track. Note that the player also has to support this method. Valid values are
      '<literal>none</literal>', '<literal>zlib</literal>', '<literal>lzo</literal>'/'<literal>lxo1x</literal>',
      '<literal>bz2</literal>'/'<literal>bzlib</literal>' and '<literal>mpeg4_p2</literal>'/'<literal>mpeg4p2</literal>'.  The values
      '<literal>lzo</literal>'/'<literal>lxo1x</literal>' and '<literal>bz2</literal>'/'<literal>bzlib</literal>' are only available if
      &mkvmerge; has been compiled with support for the <productname>liblzo</productname> respectively <productname>bzlib</productname>
      compression libraries.
     </para>

     <para>
      The compression method '<literal>mpeg4_p2</literal>'/'<literal>mpeg4p2</literal>' is a special compression method called
      '<foreignphrase>header removal</foreignphrase>' that is only available for MPEG4 part 2 video tracks. The other methods are general
      compression methods that can be used with any type of track.
     </para>

     <para>
      The default is '<literal>zlib</literal>' compression. This compression method is also the one that most if not all playback
      applications support. Support for other compression methods other than '<literal>none</literal>' is not assured.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Options that only apply to text subtitle tracks:
  </para>

  <variablelist>
   <varlistentry id="mkvmerge.description.sub_charset">
    <term><option>--sub-charset</option> <parameter>TID:character-set</parameter></term>
    <listitem>
     <para>
      Sets the character set for the conversion to UTF-8 for UTF-8 subtitles for the given track ID. If not specified the charset will be
      derived from the current locale settings. Note that a charset is not needed for subtitles read from &matroska; files or from Kate
      streams, as these are always stored in UTF-8. See the section about <link linkend="mkvmerge.text_files_and_charsets"> text files and
      character sets</link> for an explanation how &mkvmerge; converts between character sets.
     </para>

     <para>
      This option can be used multiple times for an input file applying to several tracks by selecting different track IDs each time.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   Other options:
  </para>

  <variablelist>
   <varlistentry id="mkvmerge.description.identify">
    <term><option>-i</option>, <option>--identify</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>
      Will let &mkvmerge; probe the single file and report its type, the tracks contained in the file and their track IDs. If this option is
      used then the only other option allowed is the filename.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-l</option>, <option>--list-types</option></term>
    <listitem>
     <para>
      Lists supported input file types.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.list_languages">
    <term><option>--list-languages</option></term>
    <listitem>
     <para>
      Lists all languages and their ISO639-2 code which can be used with the <link
      linkend="mkvmerge.description.language"><option>--language</option></link> option.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--priority</option> <parameter>priority</parameter></term>
    <listitem>
     <para>
      Sets the process priority that &mkvmerge; runs with. Valid values are '<literal>lowest</literal>', '<literal>lower</literal>',
      '<literal>normal</literal>', '<literal>higher</literal>' and '<literal>highest</literal>'. If nothing is given then
      '<literal>normal</literal>' is used. On Unix like systems &mkvmerge; will use the
      <citerefentry><refentrytitle>nice</refentrytitle><manvolnum>2</manvolnum></citerefentry> function. Therefore only the super user can
      use '<literal>higher</literal>' and '<literal>highest</literal>'. On Windows all values are useable for every user.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.command_line_charset">
    <term><option>--command-line-charset</option> <parameter>character-set</parameter></term>
    <listitem>
     <para>
      Sets the character set to convert strings given on the command line from. It defaults to the character set given by system's current
      locale. This settings applies to arguments of the following options: <link
      linkend="mkvmerge.description.title"><option>--title</option></link>, <link
      linkend="mkvmerge.description.track_name"><option>--track-name</option></link> and <link
      linkend="mkvmerge.description.attachment_description"><option>--attachment-description</option></link>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.output_charset">
    <term><option>--output-charset</option> <parameter>character-set</parameter></term>
    <listitem>
     <para>
      Sets the character set to which strings are converted that are to be output.  It defaults to the character set given by system's
      current locale.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.redirect_output">
    <term><option>-r</option>, <option>--redirect-output</option> <parameter>file-name</parameter></term>
    <listitem>
     <para>
      Writes all messages to the file <parameter>file-name</parameter> instead of to the console.  While this can be done easily with output
      redirection there are cases in which this option is needed: when the terminal reinterprets the output before writing it to a file.
      The character set set with <link linkend="mkvmerge.description.output_charset"><option>--output-charset</option></link> is honored.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry id="mkvmerge.description.ui_language">
    <term><option>--ui-language</option> <parameter>code</parameter></term>
    <listitem>
     <para>
      Forces the translations for the language <parameter>code</parameter> to be used (e.g.  '<literal>de_DE</literal>' for the German
      translations). It is preferable to use the environment variables <varname>LANG</varname>, <varname>LC_MESSAGES</varname> and
      <varname>LC_ALL</varname> though. Entering '<literal>list</literal>' as the <parameter>code</parameter> will cause &mkvmerge; to
      output a list of available translations.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>@</option>options-file</term>
    <listitem>
     <para>
      Reads additional command line arguments from the file <parameter>options-file</parameter>.  Lines whose first non-whitespace character
      is a hash mark ('<literal>#</literal>') are treated as comments and ignored. White spaces at the start and end of a line will be
      stripped. Each line must contain exactly one option.  There is no meta character escaping.
     </para>

     <para>
      The command line '<command>mkvmerge -o "my file.mkv" -A "a movie.avi" sound.ogg</command>' could be converted into the following
      option file:
     </para>

     <programlisting>
# Write to the file "my file.mkv".
-o
my file.mkv
# Only take the video from "a movie.avi".
-A
a movie.avi
sound.ogg
     </programlisting>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>--capabilities</option></term>
    <listitem>
     <para>
      Lists information about optional features that have been compiled in and exit. The first line output will be the version
      information. All following lines contain exactly one word whose presence indicates that the feature has been compiled in. These
      features are:
     </para>

     <itemizedlist>
      <listitem>
       <para>
        '<literal>BZ2</literal>' -- the <productname>bzlib</productname> compression library. Affects the available compression methods for
        the <link linkend="mkvmerge.description.compression"><option>--compression</option></link> option.
       </para>
      </listitem>

      <listitem>
       <para>
        '<literal>LZO</literal>' -- the <productname>lzo</productname> compression library. Affects the available compression methods for
        the <link linkend="mkvmerge.description.compression"><option>--compression</option></link> option.
       </para>
      </listitem>

      <listitem>
       <para>
        '<literal>FLAC</literal>' -- reading raw <abbrev>FLAC</abbrev> files and handling <abbrev>FLAC</abbrev> tracks in other containers,
        e.g. <productname>Ogg</productname> or &matroska;.
       </para>
      </listitem>
     </itemizedlist>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-h</option>, <option>--help</option></term>
    <listitem>
     <para>
      Show usage information and exit.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><option>-V</option>, <option>--version</option></term>
    <listitem>
     <para>
      Show version information and exit.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="mkvmerge.usage">
  <title>Usage</title>
  <para>
   For each file the user can select which tracks &mkvmerge; should take.  They are all put into the file specified with
   <option>-o</option>. A list of known (and supported) source formats can be obtained with the <option>-l</option> option.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.examples">
  <title>Examples</title>
  <para>
   Let's assume you have a file called MyMovie.avi and the audio track in a separate file, e.g. '<literal>MyMovie.wav</literal>'. First you
   want to encode the audio to &oggvorbis;:
  </para>

  <screen>$ oggenc -q4 -oMyMovie.ogg MyMovie.wav</screen>

  <para>
   After a couple of minutes you can join video and audio:
  </para>

  <screen>$ mkvmerge -o MyMovie-with-sound.mkv MyMovie.avi MyMovie.ogg</screen>

  <para>
   If your <abbrev>AVI</abbrev> already contains an audio track then it will be copied as well (if &mkvmerge; supports the audio format). To
   avoid that simply do
  </para>

  <screen>$ mkvmerge -o MyMovie-with-sound.mkv -A MyMovie.avi MyMovie.ogg</screen>

  <para>
   After some minutes of consideration you rip another audio track, e.g.  the director's comments or another language to
   '<literal>MyMovie-add-audio.wav</literal>'.  Encode it again and join it up with the other file:
  </para>

  <screen>
$ oggenc -q4 -oMyMovie-add-audio.ogg MyMovie-add-audio.wav
$ mkvmerge -o MM-complete.mkv MyMovie-with-sound.mkv MyMovie-add-audio.ogg
  </screen>

  <para>
   The same result can be achieved with
  </para>

  <screen>$ mkvmerge -o MM-complete.mkv -A MyMovie.avi MyMovie.ogg MyMovie-add-audio.ogg</screen>

  <para>
   Now fire up <productname>mplayer</productname> and enjoy. If you have multiple audio tracks (or even video tracks) then you can tell
   <productname>mplayer</productname> which track to play with the '<option>-vid</option>' and '<option>-aid</option>' options. These are
   0-based and do not distinguish between video and audio.
  </para>

  <para>
   If you need an audio track synchronized you can do that easily. First find out which track ID the Vorbis track has with
  </para>

  <screen>$ mkvmerge --identify outofsync.ogg</screen>

  <para>
   Now you can use that ID in the following command line:
  </para>

  <screen>$ mkvmerge -o goodsync.mkv -A source.avi -y 12345:200 outofsync.ogg</screen>

  <para>
   This would add 200ms of silence at the beginning of the audio track with the
   ID <constant>12345</constant> taken from '<literal>outofsync.ogg</literal>'.
  </para>

  <para>
   Some movies start synced correctly but slowly drift out of sync. For these kind of movies you can specify a delay factor that is applied
   to all timestamps -- no data is added or removed. So if you make that factor too big or too small you'll get bad results. An example is
   that an episode I transcoded was <constant>0.2</constant> seconds out of sync at the end of the movie which was
   <constant>77340</constant> frames long. At <constant>29.97fps</constant> <constant>0.2</constant> seconds correspond to
   approx. <constant>6</constant> frames. So I did
  </para>

  <screen>$ mkvmerge -o goodsync.mkv -y 23456:0,77346/77340 outofsync.mkv</screen>

  <para>
   The result was fine.
  </para>

  <para>
   The sync options can also be used for subtitles in the same manner.
  </para>

  <para>
   For text subtitles you can either use some Windows software (like <productname>SubRipper</productname>) or the
   <productname>subrip</productname> package found in
   <citerefentry><refentrytitle>transcode</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s sources in the
   '<literal>contrib/subrip</literal>' directory. The general process is:
  </para>

  <orderedlist>
   <listitem>
    <para>extract a raw subtitle stream from the source:</para>
    <screen>$ tccat -i /path/to/copied/dvd/ -T 1 -L | tcextract -x ps1 -t vob -a 0x20 | subtitle2pgm -o mymovie</screen>
   </listitem>

   <listitem>
    <para>convert the resulting PGM images to text with gocr:</para>
    <screen>$ pgm2txt mymovie</screen>
   </listitem>

   <listitem>
    <para>spell-check the resulting text files:</para>
    <screen>$ ispell -d american *txt</screen>
   </listitem>

   <listitem>
    <para>convert the text files to a SRT file:</para>
    <screen>$ srttool -s -w -i mymovie.srtx -o mymovie.srt</screen>
   </listitem>
  </orderedlist>

  <para>
   The resulting file can be used as another input file for &mkvmerge;:
  </para>

  <screen>$ mkvmerge -o mymovie.mkv mymovie.avi mymovie.srt</screen>

  <para>
   If you want to specify the language for a given track then this is easily done. First find out the ISO639-2 code for your
   language. &mkvmerge; can list all of those codes for you:
  </para>

  <screen>$ mkvmerge --list-languages</screen>

  <para>
   Search the list for the languages you need. Let's assume you have put two audio tracks into a &matroska; file and want to set their
   language codes and that their track IDs are 2 and 3. This can be done with
  </para>

  <screen>$ mkvmerge -o with-lang-codes.mkv --language 2:ger --language 3:dut without-lang-codes.mkv</screen>

  <para>
   As you can see you can use the <link linkend="mkvmerge.description.language"><option>--language</option></link> switch multiple times.
  </para>

  <para>
   Maybe you'd also like to have the player use the Dutch language as the default language. You also have extra subtitles, e.g. in English
   and French, and want to have the player display the French ones by default. This can be done with
  </para>

  <screen>$ mkvmerge -o with-lang-codes.mkv --language 2:ger --language 3:dut --default-track 3 without-lang-codes.mkv --language 0:eng english.srt --default-track 0 --language 0:fre french.srt</screen>

  <para>
   If you do not see the language or default track flags that you've specified in &mkvinfo;'s output then please read the
   section about <link linkend="mkvmerge.default_values">default values</link>.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.track_ids">
  <title>Track IDs</title>

  <para>
   Some of the options for &mkvmerge; need a track ID to specify which track they should be applied to.  Those track IDs are printed by the
   readers when demuxing the current input file, or if &mkvmerge; is called with the <link
   linkend="mkvmerge.description.identify"><option>--identify</option></link> option.  An example for such output:
  </para>

  <screen>
$ mkvmerge -i v.mkv
File 'v.mkv': container: &matroska;
Track ID 1: video (V_MS/VFW/FOURCC, DIV3)
Track ID 2: audio (A_MPEG/L3)
  </screen>

  <para>
   Track IDs are assigned like this:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     <abbrev>AVI</abbrev> files: The video track has the ID 0. The audio tracks get IDs in ascending order starting at 1.
    </para>
   </listitem>

   <listitem>
    <para>
     <abbrev>AAC</abbrev>, <abbrev>AC3</abbrev>, <abbrev>MP3</abbrev>, <abbrev>SRT</abbrev> and <abbrev>WAV</abbrev> files: The one 'track'
     in that file gets the ID 0.
    </para>
   </listitem>

   <listitem>
    <para>
     Ogg/<abbrev>OGM</abbrev> files: The track IDs are assigned in order the tracks are found in the file starting at 0.
    </para>
   </listitem>

   <listitem>
    <para>
     &matroska; files: The track's ID is the track number as reported by &mkvinfo;. It is <emphasis>not</emphasis> the track UID.
    </para>
   </listitem>
  </itemizedlist>

  <para>
   The special track ID '<constant>-1</constant>' is a wild card and applies the given switch to all tracks that are read from an input
   file.
  </para>

  <para>
   The options that use the track IDs are the ones whose description contains '<literal>TID</literal>'.
   The following options use track IDs as well: <option>--atracks</option>,
   <option>--vtracks</option>, <option>--stracks</option> and <option>--btracks</option>.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.text_files_and_charsets">
  <title>Text files and character set conversions</title>
  <note>
   <para>
    This section applies to all programs in MkvToolNix even if it only mentions &mkvmerge;.
   </para>
  </note>

  <para>
   All text in a &matroska; file is encoded in UTF-8. This means that &mkvmerge; has to convert every text file it reads as well as every
   text given on the command line from one character set into UTF-8. In return this also means that &mkvmerge;'s output has to be converted
   back to that character set from UTF-8, e.g. if a non-English translation is used with <link
   linkend="mkvmerge.description.ui_language"><option>--ui-language</option></link> or for text originating from a &matroska; file.
  </para>

  <para>
   &mkvmerge; does this conversion automatically based on the presence of a <foreignphrase>byte order marker</foreignphrase> (short:
   <abbrev>BOM</abbrev>) or the system's current locale. How the character set is inferred from the locale depends on the operating system
   that &mkvmerge; is run on.
  </para>

  <para>
   Text files that start with a BOM are already encoded in one representation of UTF. &mkvmerge; supports the following five modes: UTF-8,
   UTF-16 Little and Big Endian, UTF-32 Little and Big Endian. Text files with a BOM are automatically converted to UTF-8. Any of the
   parameters that would otherwise set the character set for such a file (e.g. <link
   linkend="mkvmerge.description.sub_charset"><option>--sub-charset</option></link>) is silently ignored.
  </para>

  <para>
   On Unix-like systems &mkvmerge; uses the <citerefentry><refentrytitle>setlocale</refentrytitle><manvolnum>3</manvolnum></citerefentry>
   system call which in turn uses the environment variables <varname>LANG</varname>, <varname>LC_ALL</varname> and
   <varname>LC_CYPE</varname>. The resulting character set is often one of UTF-8 or the ISO-8859-* family and is used for all text file
   operations and for encoding strings on the command line and for output to the console.
  </para>

  <para>
   On Windows there are actually two different character sets that &mkvmerge; uses due to the way the Windows shell program
   <command>cmd.exe</command> is implemented. The first character set is determined by a call to the <function>GetCP()</function> system
   call. This character set is used as the default for text file conversions and for all elements displayed by the <abbrev>GUI</abbrev>
   programs in the MkvToolNix package. <command>cmd.exe</command> uses another character set which is determined by a call to the
   <function>GetACP()</function> system call. This is the default character set for all strings read from the command line and for all
   strings output to the console.
  </para>

  <para>
   The following options exist that allow specifying the character sets:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     <link linkend="mkvmerge.description.sub_charset"><option>--sub-charset</option></link> for text subtitle files and for text subtitle
     tracks stored in container formats for which the character set cannot be determined unambiguously (e.g. Ogg files),
    </para>
   </listitem>

   <listitem>
    <para>
     <link linkend="mkvmerge.description.chapter_charset"><option>--chapter-charset</option></link> for chapter text files and for chapters
     and file titles stored in container formats for which the character set cannot be determined unambiguously (e.g. Ogg files for chapter
     information, track and file titles etc; MP4 files for chapter information),
    </para>
   </listitem>

   <listitem>
    <para>
     <link linkend="mkvmerge.description.command_line_charset"><option>--command-line-charset</option></link> for all strings on the command
     line,
    </para>
   </listitem>

   <listitem>
    <para>
     <link linkend="mkvmerge.description.output_charset"><option>--output-charset</option></link> for all strings written to the console or
     to a file if the output has been redirected with the <link
     linkend="mkvmerge.description.redirect_output"><option>--redirect-output</option></link> option.
    </para>
   </listitem>
  </itemizedlist>
 </refsect1>

 <refsect1 id="mkvmerge.subtitles">
  <title>Subtitles</title>
  <para>
   There are several text subtitle formats that can be embedded into &matroska;.  At the moment &mkvmerge; supports only text, VobSub and Kate
   subtitle formats. Text subtitles must be recoded to UTF-8 so that they can be displayed correctly by a player (see the section about
   <link linkend="mkvmerge.text_files_and_charsets"> text files and character sets</link> for an explanation how &mkvmerge; converts between
   character sets). Kate subtitles are already encoded in UTF-8 and do not have to be re-encoded.
  </para>

  <para>
   The following subtitle formats are supported at the moment:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     Subtitle Ripper (SRT) files
    </para>
   </listitem>

   <listitem>
    <para>
     Substation Alpha (SSA) / Advanced Substation Alpha scripts (ASS)
    </para>
   </listitem>

   <listitem>
    <para>
     OggKate streams
    </para>
   </listitem>

   <listitem>
    <para>
     VobSub bitmap subtitle files
    </para>
   </listitem>
  </itemizedlist>
 </refsect1>

 <refsect1 id="mkvmerge.file_linking">
  <title>File linking</title>
  <para>
   &matroska; supports file linking which simply says that a specific file is the predecessor or successor of the current file. To be precise,
   it's not really the files that are linked but the &matroska; segments. As most files will probably only contain one &matroska; segment the
   following explanations use the term 'file linking' although 'segment linking' would be more appropriate.
  </para>

  <para>
   Each segment is identified by a unique 128 bit wide segment UID. This UID is automatically generated by &mkvmerge;. The linking is done
   primarily via putting the segment UIDs (short: <abbrev>SID</abbrev>) of the previous/next file into the segment header
   information. &mkvinfo; prints these <abbrev>SIDs</abbrev> if it finds them.
  </para>

  <para>
   If a file is split into several smaller ones and linking is used then the timecodes will not start at 0 again but will continue where the
   last file has left off. This way the absolute time is kept even if the previous files are not available (e.g. when streaming). If no
   linking is used then the timecodes should start at 0 for each file. By default &mkvmerge; does not use file linking. If you want that you
   can turn it on with the <option>--link</option> option. This option is only useful if splitting is activated as well.
  </para>

  <para>
   Regardless of whether splitting is active or not the user can tell &mkvmerge; to link the produced files to specific
   <abbrev>SIDs</abbrev>. This is achieved with the options <option>--link-to-previous</option> and <option>--link-to-next</option>.  These
   options accept a segment <abbrev>SID</abbrev> in the format that &mkvinfo; outputs: 16 hexadecimal numbers between
   <constant>0x00</constant> and <constant>0xff</constant> prefixed with '<literal>0x</literal>' each, e.g. '<literal>0x41 0xda 0x73 0x66
   0xd9 0xcf 0xb2 0x1e 0xae 0x78 0xeb 0xb4 0x5e 0xca 0xb3 0x93</literal>'. Alternatively a shorter form can be used: 16 hexadecimal numbers
   between <constant>0x00</constant> and <constant>0xff</constant> without the '<literal>0x</literal>' prefixes and without the spaces, e.g.
   '<literal>41da7366d9cfb21eae78ebb45ecab393</literal>'.
  </para>

  <para>
   If splitting is used then the first file is linked to the <abbrev>SID</abbrev> given with <option>--link-to-previous</option> and the
   last file is linked to the <abbrev>SID</abbrev> given with <option>--link-to-next</option>. If splitting is not used then the one output
   file will be linked to both of the two <abbrev>SIDs</abbrev>.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.default_values">
  <title>Default values</title>
  <para>
   The &matroska; specification states that some elements have a default value. Usually an element is not written to the file if its value
   is equal to its default value in order to save space. The elements that the user might miss in &mkvinfo;'s output are the
   <parameter>language</parameter> and the <parameter>default track flag</parameter> elements.  The default value for the
   <parameter>language</parameter> is English ('<literal>eng</literal>'), and the default value for the <parameter>default track
   flag</parameter> is <parameter>true</parameter>. Therefore if you used <option>--language 0:eng</option> for a track then it will not
   show up in &mkvinfo;'s output.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.attachments">
  <title>Attachments</title>
  <para>
   Maybe you also want to keep some photos along with your &matroska; file, or you're using <abbrev>SSA</abbrev> subtitles and need a
   special <productname>TrueType</productname> font that's really rare. In these cases you can attach those files to the &matroska;
   file. They will not be just appended to the file but embedded in it. A player can then show those files (the 'photos' case) or use them
   to render the subtitles (the '<productname>TrueType</productname> fonts' case).
  </para>

  <para>
   Here's an example how to attach a photo and a <productname>TrueType</productname> font to the output file:
  </para>

  <screen>
$ mkvmerge -o output.mkv -A video.avi sound.ogg --attachment-description "Me and the band behind the stage in a small get-together" --attachment-mime-type image/jpeg --attach-file me_and_the_band.jpg --attachment-description "The real rare and unbelievably good looking font" --attachment-type application/octet-stream --attach-file really_cool_font.ttf
  </screen>

  <para>
   If a &matroska; containing attachments file is used as an input file then &mkvmerge; will copy the attachments into the new file. The
   selection which attachments are copied and which are not can be changed with the options <link
   linkend="mkvmerge.description.attachments"><option>--attachments</option></link> and <link
   linkend="mkvmerge.description.no_attachments"><option>--no-attachments</option></link>.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.chapters">
  <title>Chapters</title>
  <para>
   The &matroska; chapter system is more powerful than the old known system used by <abbrev>OGM</abbrev> files. The full specifications can
   be found at <ulink url="http://www.matroska.org/">the &matroska; website</ulink>.
  </para>

  <para>
   &mkvmerge; supports two kinds of chapter files as its input. The first format, called '<foreignphrase>simple chapter
   format</foreignphrase>', is the same format that the <abbrev>OGM</abbrev> tools expect. The second format is a &xml; based
   chapter format which supports all of &matroska;'s chapter functionality.
  </para>

  <refsect2>
   <title>The simple chapter format</title>

   <para>
    This formmat consists of pairs of lines that start with '<literal>CHAPTERxx=</literal>' and '<literal>CHAPTERxxNAME=</literal>'
    respectively. The first one contains the start timecode while the second one contains the title. Here's an example:
   </para>

   <screen>
CHAPTER01=00:00:00.000
CHAPTER01NAME=Intro
CHAPTER02=00:02:30.000
CHAPTER02NAME=Baby prepares to rock
CHAPTER03=00:02:42.300
CHAPTER03NAME=Baby rocks the house
   </screen>

   <para>
    &mkvmerge; will transform every pair or lines into one &matroska; <classname>ChapterAtom</classname>. It does not set any
    <classname>ChapterTrackNumber</classname> which means that the chapters all apply to all tracks in the file.
   </para>

   <para>
    As this is a text file character set conversion may need to be done. See the section about <link
    linkend="mkvmerge.text_files_and_charsets"> text files and character sets</link> for an explanation how &mkvmerge; converts between
    character sets.
   </para>
  </refsect2>

  <refsect2>
   <title>The &xml; based chapter format</title>
   <para>
    The &xml; based chapter format looks like this example:
   </para>

   <screen>
&lt;?xml version=&quot;1.0&quot; encoding=&quot;ISO-8859-1&quot;?&gt;
&lt;!DOCTYPE Chapters SYSTEM &quot;matroskachapters.dtd&quot;&gt;
&lt;Chapters&gt;
  &lt;EditionEntry&gt;
    &lt;ChapterAtom&gt;
      &lt;ChapterTimeStart&gt;00:00:30.000&lt;/ChapterTimeStart&gt;
      &lt;ChapterTimeEnd&gt;00:01:20.000&lt;/ChapterTimeEnd&gt;
      &lt;ChapterDisplay&gt;
        &lt;ChapterString&gt;A short chapter&lt;/ChapterString&gt;
        &lt;ChapterLanguage&gt;eng&lt;/ChapterLanguage&gt;
      &lt;/ChapterDisplay&gt;
      &lt;ChapterAtom&gt;
        &lt;ChapterTimeStart&gt;00:00:46.000&lt;/ChapterTimeStart&gt;
        &lt;ChapterTimeEnd&gt;00:01:10.000&lt;/ChapterTimeEnd&gt;
        &lt;ChapterDisplay&gt;
          &lt;ChapterString&gt;A part of that short chapter&lt;/ChapterString&gt;
          &lt;ChapterLanguage&gt;eng&lt;/ChapterLanguage&gt;
        &lt;/ChapterDisplay&gt;
      &lt;/ChapterAtom&gt;
    &lt;/ChapterAtom&gt;
  &lt;/EditionEntry&gt;
&lt;/Chapters&gt;
   </screen>

   <para>
    With this format three things are possible that are not possible with the simple chapter format:
   </para>

   <orderedlist>
    <listitem><para>The timestamp for the end of the chapter can be set,</para></listitem>
    <listitem><para>chapters can be nested,</para></listitem>
    <listitem><para>the language and country can be set.</para></listitem>
   </orderedlist>

   <para>
    The mkvtoolnix distribution contains some sample files in the <filename>doc</filename> subdirectory which can be used as a basis.
   </para>
  </refsect2>

  <refsect2>
   <title>General notes</title>
   <para>
    When splitting files &mkvmerge; will correctly adjust the chapters as well. This means that each file only includes the chapter entries
    that apply to it, and that the timecodes will be offset to match the new timecodes of each output file.
   </para>

   <para>
    &mkvmerge; is able to copy chapters from &matroska; source files unless this is explicitly disabled with the <link
    linkend="mkvmerge.description.no_chapters"><option>--no-chapters</option></link> option. The chapters from all sources (&matroska; files,
    Ogg files, <abbrev>MP4</abbrev> files, chapter text files) are usually not merged but end up in separate
    <classname>ChapterEditions</classname>. Only if chapters are read from several &matroska; or &xml; files that share the
    same edition UIDs will chapters be merged into a single <classname>ChapterEdition</classname>. If such a merge is desired in other
    situations as well then the user has to extract the chapters from all sources with &mkvextract; first, merge the &xml;
    files manually and mux them afterwards.
   </para>
  </refsect2>
 </refsect1>

 <refsect1 id="mkvmerge.tags">
  <title>Tags</title>

  <refsect2>
   <title>Introduction</title>

   <para>
    &matroska; supports an extensive set of tags that is deprecated and a new, simpler system like it is is used in most other containers:
    <parameter>KEY=VALUE</parameter>. However, in &matroska; these tags can also be nested, and both the <parameter>KEY</parameter> and the
    <parameter>VALUE</parameter> are elements of their own. The example file <filename>example-tags-2.xml</filename> shows how to use this
    new system.
   </para>
  </refsect2>

  <refsect2>
   <title>Scope of the tags</title>

   <para>
    &matroska; tags do not automatically apply to the complete file. They can, but they also may apply to different parts of the file: to one
    or more tracks, to one or more chapters, or even to a combination of both. The <ulink
    url="http://matroska.org/technical/specs/index.html">the &matroska; specification</ulink> gives more details about this fact.
   </para>

   <para>
    One important fact is that tags are linked to tracks or chapters with the <classname>Targets</classname> &matroska; tag element, and
    that the UIDs used for this linking are <emphasis>not</emphasis> the track IDs &mkvmerge; uses everywhere. Instead the numbers used are
    the UIDs which &mkvmerge; calculates automatically (if the track is taken from a file format other than &matroska;) or which are copied
    from the source file if the track's source file is a &matroska; file. Therefore it is difficult to know which UIDs to use in the tag
    file before the file is handed over to &mkvmerge;.
   </para>

   <para>
    &mkvmerge; knows two options with which you can add tags to &matroska; files: The <link
    linkend="mkvmerge.description.global_tags"><option>--global-tags</option></link> and the <link
    linkend="mkvmerge.description.tags"><option>--tags</option></link> options. The difference is that the former option, <link
    linkend="mkvmerge.description.global_tags"><option>--global-tags</option></link>, will make the tags apply to the complete file by
    removing any of those <classname>Targets</classname> elements mentioned above.  The latter option, <link
    linkend="mkvmerge.description.tags"><option>--tags</option></link>, automatically inserts the UID that &mkvmerge; generates for the tag
    specified with the <parameter>TID</parameter> part of the <link linkend="mkvmerge.description.tags"><option>--tags</option></link>
    option.
   </para>
  </refsect2>

  <refsect2>
   <title>Example</title>
   <para>
    Let's say that you want to add tags to a video track read from an <abbrev>AVI</abbrev>. <command>mkvmerge --identify file.avi</command>
    tells you that the video track's ID (do not mix this ID with the UID!) is 0. So you create your tag file, leave out all
    <classname>Targets</classname> elements and call &mkvmerge;:
   </para>

   <screen>
$ mkvmerge -o file.mkv --tags 0:tags.xml file.avi
   </screen>
  </refsect2>

  <refsect2>
   <title>Tag file format</title>
   <para>
    &mkvmerge; supports a &xml; based tag file format. The format is very closely modeled after <ulink
    url="http://matroska.org/technical/specs/index.html">the &matroska; specification</ulink>. Both the binary and the source distributions
    of MkvToolNix come with a sample file called <filename>example-tags-2.xml</filename> which simply lists all known tags and which can be
    used as a basis for real life tag files.
   </para>

   <para>
    The basics are:
   </para>

   <itemizedlist>
    <listitem><para>The outermost element must be <classname>&lt;Tags&gt;</classname>.</para></listitem>
    <listitem>
     <para>One logical tag is contained inside one pair of <classname>&lt;Tag&gt;</classname> &xml; tags.</para>
    </listitem>
    <listitem><para>White spaces directly before and after tag contents are ignored.</para></listitem>
   </itemizedlist>
  </refsect2>

  <refsect2>
   <title>Data types</title>
   <para>
    The new &matroska; tagging system only knows two data types, a UTF-8 string and a binary type. The first is used for the tag's name and
    the <classname>&lt;String&gt;</classname> element while the binary type is used for the <classname>&lt;Binary&gt;</classname> element.
   </para>

   <para>
    As binary data itself would not fit into a &xml; file &mkvmerge; supports two other methods of storing binary data. If the contents of a
    &xml; tag starts with '<literal>@</literal>' then the following text is treated as a file name. The corresponding file's content is
    copied into the &matroska; element.
   </para>

   <para>
    Otherwise the data is expected to be <foreignphrase>Base64</foreignphrase> encoded. This is an encoding that transforms binary data into
    a limited set of <abbrev>ASCII</abbrev> characters and is used e.g. in email programs. &mkvextract; will output
    <foreignphrase>Base64</foreignphrase> encoded data for binary elements.
   </para>

   <para>
    The deprecated tagging system knows some more data types which can be found in the official &matroska; tag specs. As &mkvmerge; does not
    support this system anymore these types aren't described here.
   </para>
  </refsect2>
 </refsect1>

 <refsect1 id="mkvmerge.file_layout">
  <title>&matroska; file layout</title>
  <para>
   The &matroska; file layout is quite flexible. &mkvmerge; will render a file in a predefined way. The resulting file looks like this:
  </para>

  <para>
   [EBML head] [segment {meta seek #1} {attachments} {chapters} [segment information] [track information] [cluster 1] {cluster 2} ...
   {cluster n} {cues} {meta seek #2} {tags}]
  </para>

  <para>
   The elements in curly braces are optional and depend on the contents and options used. A couple of notes:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     meta seek #1 includes only a small number of level 1 elements, and only if they actually exist: attachments, chapters, cues, tags, meta
     seek #2. Older versions of &mkvmerge; used to put the clusters into this meta seek element as well. Therefore some imprecise guessing
     was necessary to reserve enough space. It often failed. Now only the clusters are stored in meta seek #2, and meta seek #1 refers to
     the meta seek element #2.
    </para>
   </listitem>

   <listitem>
    <para>Attachment, chapter and tag elements are only present if they were added.</para>
   </listitem>
  </itemizedlist>

  <para>
   The shortest possible Matroska file would look like this:
  </para>

  <para>
   [EBML head] [segment [segment information] [track information] [cluster 1]]
  </para>

  <para>
   This might be the case for audio-only files.
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.external_timecode_files">
  <title>External timecode files</title>
  <para>
   &mkvmerge; allows the user to chose the timecodes for a specific track himself. This can be used in order to create files with variable
   frame rate video or include gaps in audio. A frame in this case is the unit that &mkvmerge; creates separately per &matroska; block. For
   video this is exactly one frame, for audio this is one packet of the specific audio type. E.g. for <abbrev>AC3</abbrev> this would be a
   packet containing <constant>1536</constant> samples.
  </para>

  <para>
   Timecode files that are used when tracks are appended to each other must only be specified for the first part in a chain of tracks.  For
   example if you append two files, v1.avi and v2.avi, and want to use timecodes then your command line must look something like this:
  </para>

  <screen>
mkvmerge ... --timecodes 0:my_timecodes.txt v1.avi +v2.avi
  </screen>

  <para>
   There are four formats that are recognized by &mkvmerge;. The first line always contains the version number. Empty lines, lines
   containing only whitespace and lines beginning with '<literal>#</literal>' are ignored.
  </para>

  <refsect2>
   <title>Timecode file format v1</title>
   <para>
    This format starts with the version line. The second line declares the default number of frames per second.  All following lines contain
    three numbers separated by commas: the start frame (<constant>0</constant> is the first frame), the end frame and the number of frames
    in this range. The <abbrev>FPS</abbrev> is a floating point number with the dot '<literal>.</literal>' as the decimal point. The ranges
    can contain gaps for which the default <abbrev>FPS</abbrev> is used. An example:
   </para>

   <screen>
# timecode format v1
assume 27.930
800,1000,25
1500,1700,30
   </screen>
  </refsect2>

  <refsect2>
   <title>Timecode file format v2</title>

   <para>
    In this format each line contains a timecode for the corresponding frame.  This timecode must be given in millisecond precision.  It can
    be a floating point number, but it doesn't have to be.  You <emphasis>have to</emphasis> give at least as many timecode lines as there
    are frames in the track.  The timecodes in this file must be sorted.  Example for 25fps:
   </para>

   <screen>
# timecode format v2
0
40
80
   </screen>
  </refsect2>

  <refsect2>
   <title>Timecode file format v3</title>
   <para>
    In this format each line contains a duration in seconds followed by an optional number of frames per second.  Both can be floating point
    numbers.  If the number of frames per second is not present the default one is used.  For audio you should let the codec calculate the
    frame timecodes itself.  For that you should be using <constant>0.0</constant> as the number of frames per second.  You can also create
    gaps in the stream by using the '<literal>gap</literal>' keyword followed by the duration of the gap.  Example for an audio file:
   </para>

   <screen>
# timecode format v3
assume 0.0
25.325
7.530,38.236
gap, 10.050
2.000,38.236
   </screen>
  </refsect2>

  <refsect2>
   <title>Timecode file format v4</title>
   <para>
    This format is identical to the v2 format.  The only difference is that the timecodes do not have to be sorted.  This format should
    almost never be used.
   </para>
  </refsect2>
 </refsect1>

 <refsect1>
  <title>Exit codes</title>

  <para>
   &mkvmerge; exits with one of three exit codes:
  </para>

  <itemizedlist>
   <listitem>
    <para>
     <constant>0</constant> -- This exit codes means that muxing has completed successfully.
    </para>
   </listitem>

   <listitem>
    <para>
     <constant>1</constant> -- In this case &mkvmerge; has output at least one warning, but muxing did continue.  A warning is prefixed with
     the text '<literal>Warning:</literal>'.  Depending on the issues involved the resulting file might be ok or not.  The user is urged to
     check both the warning and the resulting file.
    </para>
   </listitem>

   <listitem>
    <para>
     <constant>2</constant> -- This exit code is used after an error occured.  &mkvmerge; aborts right after outputting the error message.
     Error messages range from wrong command line arguments over read/write errors to broken files.
    </para>
   </listitem>
  </itemizedlist>
 </refsect1>

 <refsect1 id="mkvmerge.seealso">
  <title>See also</title>
  <para>
   &mkvinfo;, &mkvextract;, &mkvpropedit;, &mmg;
  </para>
 </refsect1>

 <refsect1 id="mkvmerge.www">
  <title>WWW</title>
  <para>
   The latest version can always be found at <ulink url="http://www.bunkus.org/videotools/mkvtoolnix/">the MKVToolNix homepage</ulink>.
  </para>
 </refsect1>

</refentry>
