(Note: simply copied from www.matroska.org.)
Matroska aims to become THE Standard of Multimedia Container Formats. It was derived from a project called MCF, but differentiates from it significantly because it is based on EBML (Extensible Binary Meta Language), a binary derivative of XML. EBML enables the Matroska Development Team to gain significant advantages in terms of future format extensibility, without breaking file support in old parsers.
If you need any more info please head over to Matroska's homepage.
mkvmerge and mkvmerge GUI (or just mmg) are two programs created by Moritz Bunkus. They're part of the mkvtoolnix package. mkvmerge can read a lot of different multimedia files and put their contents into Matroska files. Unfortunately this is a command line program, and not everyone is comfortable working on the command line. This is where mkvmerge GUI comes into play. It is a GUI that provides the user with an intuitive but powerful interface to mkvmerge.
Both programs are available for both Windows and GNU/Linux and other Unix derivatives. The program is licensed under the GPL, so the source code is available to anyone interested.
You can always find the latest version of mkvtoolnix on Moritz Bunkus' website. Windows users will have to download the runtime DLLs as well as the mkvtoolnix binaries. Linux/Unix users will probably download the sources and compile mkvtoolnix themselves.
This guide only focusses on the GUI part of these tools. All command line options are explained in detail in mkvmerge's man page/HTML page.
(Note: This section does not cover compilation and
installation. mkvmerge's own documentation and the
README files that are included in the mkvtoolnix
package.)
The only thing that mmg needs to know is the location of the mkvmerge binary. Under normal circumstances it will be found automatically. But if not then you can select the binary to use on the Settings tab.
mkvmerge strictly differentiates between files and tracks. An input file usually contains one or more tracks. mkvmerge needs at least one input file and the file name of the Matroska file it should create before it can do any work. Starting with this minimal set of options the user can add more input files, select advanced options for each track, apply some more global options etc.
The typical basic steps are:
When mmg starts up it shows the first and probably most important tab: the input tab. Here you see four different elements. The topmost input box lists all input files. Directly under this box are options that apply to the currently selected input file.
The two buttons to the right of the upper list box can be used to add files to the list box with the + button and to remove the selected entry with the - button.
Once the user selects an input file in the upper list box the second list box will contains all tracks that can be read from this file. For each of these tracks the user can select track specific options with the input boxes and check boxes below the track listing. These options will be described in the following sections.
Once the user has added and selected an input file he can set
options that apply to this specific file. At the moment only one such
option has been implemented: No chapters. If this option
is checked then mkvmerge will not try to copy chapters from
this source file. More information about chapters can be found in the
section about the chapter
editor in this document and in mkvmerge's own
documentation.
Depending on the type of the currently selected track (audio,
video, subtitles) and even depending on the contents of the track only
a subset of all the track specific options are availbale. The options
are:
Language: The user can select the language for each
track regardless of its type. This language is coded in the ISO639-2
language code. The drop-down box contains all ISO639-2 codes so the
user does not have to worry about selecting the wrong language
code.Track name: The user can set a name for the current
track. This name is a free-form string. Practical examples could be
'director's comments' or 'aeriel view of Seattle'. Note that these
names are not meant to contain the movie title!Cues: The cues are for Matroska what the
index is for AVI files. They contain links to the key
frames. Usually this option should be left on the value
'default'. mkvmerge will automatically chose the best method
for any given track type. A full explanantion of tracks can be found
in mkvmerge's documentation.Aspect ratio: With this option the user can set the
aspect ratio that should be used upon playback. It defaults to the
aspect ratio that the movie was encoded with but can be changed,
e.g. for anamorphic encodings. The GUI expects the format to be
either a floating point number (e.g. '2.33') or a fraction
(e.g. '16/9').
FourCC: Matroska does not normally store the FourCC
which is used in other containers to identify the codec
used. Matroska has its own format, called CodecID, but it
also has an AVI compatibility mode. In thise mode the FourCC is also
stored. With this option the FourCC can be forced to a different
value. However, you cannot change the CodecID used by
mkvmerge.
Delay (in ms): In some cases audio and video are
not synchronized properly. With this option the user can offset the
audio track by a given amount, either positive or
negative. mkvmerge will either remove samples at the
beginning or insert silence at the beginning to adjust the track.
Stretch by: In some cases audio and video slowly
drift apart during playback. This can be fixed by supplying a factor
of how much the timecodes should be stretched by mkvmerge. If
nothing is given then '1.0' is assumed which does not alter the
timecodes. Please note that this option has not been implemented for
all audio track types yet.
Subtitle charset: Some text subtitle formats do not
store the charset that they were creted with. This is important
because text subtitles are auomatically converted to the UTF-8
charset during muxing. mkvmerge will normally assume that the
system's current charset is the same that the subtitle file was
written in. But in case this is not true the user can select the
correct charset.
Make default track: Matroska knows a flag which
tells the player that a specific track should be preferred upon
playback if the user does not chose another one. Of course each
track type has its own default track - e.g. the default audio
track is the English one, and the default subtitle track is the
French one. If no track is set to be the default track then
mkvmerge will promote the first track of each type that it
finds to be the default track. This is consistent with the behaviour
of various media players.AAC is SBR/HE-AAC/AAC+: The new technology called
'high efficiency AAC' has some drawbacks when it is being stored in
.AAC files: it is not possible to detect the HE-AAC
part for these files. Therefore the user has to check this option
manually if it applies. Please note that this problem does not exist
for HE-AAC stored in .MP4 files.