Matroska FAQ

[ChristianHJW]

1) What is matroska? I have heard it is a "container format"? What's that?
A container format allows you to combine different multimedia streams (most of the time audio and video) into one single file.
Multimedia containers are for example the well known AVI (.avi), MPEG (.mpg, .mpeg), OGM (.ogm), MP4 (.mp4) or Realmedia (.rm, .rmvb)

The matroska project is a free, opensource container format, aiming to be able to offer a lot of advanced features, which older formats like AVI can't handle, on an extensible basis.
Matroska supports for example the storage of Variable Bitrate audio content (VBR) without any hassles, Variable Framerates (VFR), Chapters, attachment of files, Error Detection (EDC) and modern A/V Codecs like "Advanced Audio Coding" (AAC), "Ogg Vorbis" or "Realvideo 9" (RV9), next to nothing handled by AVI

2) What extensions is matroska using?
- .mkv: generally video files (with or without audio)
- .mka: audio only files, can contain any supported audio format, such as MP2, MP3, Vorbis, AAC, AC3, DTS...
- .mks: a so called "elementary" matroska stream, containing any subtitles stream

3) How can i create matroska files?
with the following tools you can create or edit matroska files (for example transmux from exisiting AVI files):
- MKVtoolnix (http://www.bunkus.org/videotools/mkvtoolnix/index.html) includes the mkvmerge commandline tool (+ gui), can mux vobsub subtitles!
- VirtualDubMod (http://sourceforge.net/projects/virtualdubmod/), choose .mkv as output file type in the "save as" dialog. VDM allows editing of matroska files too (Doom9 Guide (http://www.doom9.org/vdubmod-procedures.htm))
- AVI-Mux GUI (http://www.alexander-noe.com/video/amg/)
- Graphedit (http://www.doom9.org/Soft21/Audio/graphedit.rar), advanced users can also use gabest's matroska muxer (http://sourceforge.net/projects/guliverkli/) filter

4) Does transmuxing to matroska reencode the content?
No, this is a lossless process, only taking out the media streams from one container and putting them into matroska

5) After appending/joining two matroska files in virtualdubmod, the output seems to have some failures?
this is a known issue in virtualdubmod. Use AVI-Mux GUI for appending/joining matroska files!

6) Are my now created matroska files going to be compatible with future matroska implementations?
Yes, files being created now are fully spec compliant. in fact matroska is based on a very flexible underlying framework called EBML (http://ebml.sourceforge.net/), which allows to add more functionalities to the container format in the future (for example new A/V codecs, DVD-like menues) without breaking backwards compatibility with older software and files.

7) How can i play matroska files on Windows?
easy answer: the matroska team already prepared an install pack for you, which will enable you to play back nearly any matroska file on all directshow based players (for example media player classic (http://sourceforge.net/projects/guliverkli/), bsplayer (http://www.bsplayer.org/), zoomplayer (http://www.inmatrix.com/zplayer/) or the crappy windows media player). get it from here (http://packs.matroska.org)

detailed answer: two things are needed for playback in any directshow based player:
- a splitter filter, which splits up the container file into the included streams (audio, video, subtitles) during playback
- a decoder filter, which decodes the encoded streams (for example with XviD, MP3...)
so to say the only thing you need to playback a matroska file is the matroska splitter filter (there are three available, from gabest (http://sourceforge.net/projects/guliverkli/), Haali (http://haali.cs.msu.ru/mkv/) and mkxds (http://www.matroska.org/downloads/windows.html)) and of course the specific decoder filter (for example Vorbis (http://corevorbis.corecodec.org/), AAC (http://coreaac.corecodec.org/), Realmedia (http://sourceforge.net/projects/guliverkli/), AC3 (http://sourceforge.net/projects/ac3filter) or VSFilter (http://sourceforge.net/projects/guliverkli/))
btw. the only reason why you don't have to install a splitter for AVI is that it is already installed on windows by default (the same as the MP3 decoder)

small HOWTO (http://forum.doom9.org/showthread.php?s=&threadid=64580) install/register such DirectShow Filters

as alternative there is also The Core Media Player (http://www.corecoded.com/) with the matroska plugin (http://cvs.corecodec.org/cgi-bin/viewcvs.cgi/*checkout*/matroska/doc/website/downloads/shellextension/index.html)

8) How can i play matroska files on Linux, MacOS and X-Box?
you have to get the newest version of mplayer (http://www.mplayerhq.hu/), for file creation/editing you find everything you need on Mosu's site (http://www.bunkus.org/videotools/mkvtoolnix/). There is also a nice Gstreamer plugin by Ronald 'BBB' Bultje, which you can find in the GStreamer CVS (http://www.gstreamer.net/)

9) Does Matroska need more Processor Power than AVI?
No, you can't tell a difference while reading back AVI or Matroska content on today's processors. Writing currently takes more, but that is mostly because time is needed to refine the writing apps for MKV.

10) What subtitle types can be muxed into matroska? How can i play them?
currently SRT, SSA, ASS and Vobsub
use gabest's VSFilter (http://sourceforge.net/projects/guliverkli/) to play subs on dshow based players

11) Why are some matroska files created from AVI smaller than the source itself?
because matroska needs less overhead than the AVI container (especially with vbr-mp3)
you can find a nice overhead comparison by alexnoe here (http://www-user.tu-chemnitz.de/~noe/Video-Zeug/AVIMux%20GUI/en_overhead_comparison.html)

12) Is it possible to create variable frame rate (VFR) content in matroska?
Yes, for how to do it check out the following threads: 1 (http://forum.doom9.org/showthread.php?s=&threadid=64314) 2 (http://forum.doom9.org/showthread.php?s=&threadid=68562) 3 (http://forum.doom9.org/showthread.php?s=&threadid=68831)
AVI-Mux GUI can also join AVI files with different framerates into a matroska file.
There also was a project working on vfr-encoding, called Variable Framerate Encoder (http://corecodec.org/projects/vfre/). they released an app which lets you join vfr AVIs

13) Does Matroska support "anamorphic resize"?
Yes, you can set the display size of your matroska files for example in mkvmerge, AVI-Mux GUI or in your windows explorer by using the matroska shell extension (http://cvs.corecodec.org/cgi-bin/viewcvs.cgi/*checkout*/matroska/doc/website/downloads/shellextension/index.html)
To playback anamorphic content with the right display size you need ffdshow (http://sourceforge.net/projects/ffdshow) installed with the "overlay mixer" option ticked

14) What is the advantage of putting audio only into .mka?
read more about what can be possible at matroska.org (http://www.matroska.org/technical/guides/faq/index.html).
currently it is already possible to store a whole CD as 1 track in mka, each song seperately choosable and tagged and you can already play it in any dshow based player or in foobar2000 (http://www.foobar2000.org/) with the plugin from jcsston (http://webjory.tripod.com/fb2k/#foo_matroska)

15) Does Matroska support multi-angle video files (multiple video streams in one matroska file)?
yes, you can create such files with gabest's mkv muxer in graphedit or mkvmerge. playback works with Haali's mkv splitter in directshow

16) How can i create Chapter files in the Matroska XML format?
You can use Toff's ChapterXtractor for that, read more here (http://forum.doom9.org/showthread.php?s=&threadid=67672)

17) How can i convert from Matroska to another format? for example to AVI/MPEG?
thanks to Avalon for writing a nice small guide on how to do this! find it here (http://forum.doom9.org/showthread.php?s=&threadid=72801)
beaware that you can't put Vorbis and RV9, which are often used in Matroska, into AVI without reencoding

18) I want to read more about matroska! Where can i find more info?
feel free to visit the official matroska homepage at matroska.org (http://www.matroska.org/), there you'll find much more information, as this sticky is only meant as a starting point for newbies to handle matroska
(or you just search the doom9 forum, as most of the matroska guys are around here too :) )

cheers,
bond

[bond]

If you have any suggestions or ideas which questions to add to make the Matroska FAQ better, feel free to attach them below!
I will do my best to keep the FAQ up-to-date :)

Please don't use this sticky to discuss any Matroska issues, this thread is meant for info only!
If you have any questions, plz search the forum if they haven't been answered already and only then start a new thread

thanks,
bond

[pieroxy]

7) and 8): vlc plays matroska files fine on Windows AND linux.

7) media player classic also does on Windows...

Thanks for the nice infos.

[Rasqual]

Q: Is Matroska supported by some hardware (home, or portable devices) players? Is libmatroska easily portable? (discussed here but also in other threads)

[Zep]

7) and 8): vlc plays matroska files fine on Windows AND linux.


Thanks for the nice infos.


and OSX

[delacroixp]

13)Does Matroska support "anamorphic resize"?

The shell extension (http://cvs.corecodec.org/cgi-bin/viewcvs.cgi/*checkout*/matroska/doc/website/downloads/shellextension/index.html) link seams to be out of action...


:):D:eek:
Pascal

[SvT]

13)Does Matroska support "anamorphic resize"?

The shell extension (http://cvs.corecodec.org/cgi-bin/viewcvs.cgi/*checkout*/matroska/doc/website/downloads/shellextension/index.html) link seams to be out of action...


:):D:eek:
Pascal

You can find it here.

http://www.matroska.org/downloads/shellextension/index.html

Great project b.t.w.

:helpful:

[delacroixp]

You can find it here.

Shell Extension and TCMP CDL (http://www.matroska.org/downloads/shellextension/index.html)

Great project b.t.w.

:helpful:

:thanks: much...

Perhaps someone in command of the Matraska FAQ could update the link for future users... attention to detail is key...
It creates the mistaken impression that MKV is on it's way OUT, rather than that it is on it's way UP...


:):D:eek:
Pascal

[morph166955]

11) Why are some matroska files created from AVI smaller than the source itself?
because matroska needs less overhead than the AVI container (especially with vbr-mp3)
you can find a nice overhead comparison by alexnoe here (http://www-user.tu-chemnitz.de/~noe/Video-Zeug/AVIMux%20GUI/en_overhead_comparison.html)


That URL is no longer working, is it possible for someone to upload that comparison again somewhere?

[buzzqw]

here http://www.alexander-noe.com/video/amg/en_overhead_comparison.html

BHH

[corporalgator]

7) How to play in Windows:

The KMplayer can play mkv files straight out of the box without the need to install the haali splitter nor any ffdshow filters nor vobsub. Only player I know of that can directly display multiple subtitles straight out of the mkv container itself without the need of external filters; just make sure you switch to draw to VMR surface under subtitle options. It's freeware.

http://www.kmplayer.com/forums/showthread.php?t=4094

[XeoneR]

Is there any way to trim mkv file?....
Without content transcoding, of course...

[buzzqw]

use mmg.exe (in mkvtoolnix) and in global -> use the split fuction

BHH

[BlackSharkfr]

I have a feature request for a future matroska revision,
What is the most efficient way to ask the developpers for my feature request and get feedback ?

[Guest]

http://matroska.org/contact/index.html

[BlackSharkfr]

will send my request to the corecodec email link, thanks neuron

[delacroixp]

will send my request to the corecodec email link, thanks neuron

Good Luck !!!


It's all good !
:):devil::D
Pascal

[halsboss]

Um, maybe the FAQ could point out methods of opening an MKV in avisynth ?

[LoRd_MuldeR]

Um, maybe the FAQ could point out methods of opening an MKV in avisynth ?

http://forum.doom9.org/showthread.php?t=127037

[Bilkoff]

How many tracks can contain the mkv files?
How many tracks can be played with Haali splitter? And with Gabest's one?

[Nemesis7]

Does matroska support tagging like mp4box does? It would be great to be able to put all of the movie information (title, director, plot, rating, etc.) and the movie poster into 1 file.

Nevermind: it does support tagging. Any manual on this?

[Keiyakusha]

Foobar2000 is able to write mkv tags. But no cover. But I think support for this tags in mediaplayers is not so good.

[blackEyEz]

Could the OP be updated for HD audio like true-hd and DTS-HD? More mkv's are released with hd-audio and im having big problems with Haali in this matter.

[Inspector.Gadget]

More mkv's are released with hd-audio and im having big problems with Haali in this matter.

Doom9 FAQs don't cover pirated content as a rule (http://forum.doom9.org/forum-rules.htm).

[jasonwc]

MKVMerge can now merge SUP subs as well.

Also, you can remux your own purchased BDs with TrueHD and DTS-HD MA, so such discussions don't necessary relate to piracy. Not all countries have laws similar to the US, such that breaking a DRM scheme to make a personal copy isn't necessary a violation of the law.

[Inspector.Gadget]

Key word: "released". Nobody here disputes the right of people to back up media they own, and in fact such an update would be useful for dealing with such files made legitimately.

[SeeMoreDigital]

The FAQ could do with information about HD audio stream compatibility in hardware playback devices.

Particularily clarification regarding the, one audio stream per audio track limitation.


Cheers

[Keiyakusha]

one audio stream per audio track limitation.
You mean that we can't have THD+core as one track? This is mkvmerge limitation, not matroska.

[szabi]

Hi

Are there any program to edit tag info in mkv?
Of course with no remuxing necessity. :)

Bye
szabi

[szabi]

It looks like no way.:cool:

[sneaker_ger]

You can do it using mkvtoolnix.
Use mkvmerge GUI > File > Header Editor or "mkvpropedit" over the command line.

[szabi]

Yeah, it is working.
Thanx.

[Lincoln Burrows]

Have you guys had a hard time trying to put any MPEG-2 contents into a MKV container? I think Youtube is not recognizing these kinds of files, and I am unable to convert this thing properly. In this case, it was some extra featurette from a DVD converted by MakeMKV. I will look into this thoroughly, but I was wondering if MKV really supports MPEG-2.

[szabi]

I did it some months ago and there was no problem with it, but i did not check whether youtube can use it or not.

bye
szabi

[Midzuki]

...
but I was wondering if MKV really supports MPEG-2.

Yes, it does.
Older versions of Haali Media Splitter had no problems with MPEG-video in Matroska.

[DMD]

Good morning.

Briefly explain the problem I have found

My goal is to be included in the MKV container stream of the DVD.
To do this I am currently experimenting PGCDemux (http://download.videohelp.com/jsoto/dvdtools.htm) to extract video and audio stream, use DVDSubEdit (http://download.videohelp.com/DVDSubEdit/) also to extract forced subtitles. After use mkvmerge (http://www.bunkus.org/videotools/mkvtoolnix/) to make the final muxing

I noticed this problem:
Why is the subtitle stream format ".sup" demuxed from DVD (DVDSubEdit) is not loaded and that on the Blu-ray disc is loaded normally?

sup file from DVD demuxed
http://img840.imageshack.us/img840/1908/screenshot001rl.png (http://img840.imageshack.us/i/screenshot001rl.png/)


sup file from Blu-ray demuxed
http://img17.imageshack.us/img17/6638/screenshot002uj.png (http://img17.imageshack.us/i/screenshot002uj.png/)


thanks

[sneaker_ger]

Those are essentially different formats. mkvmerge can use .idx/.sub style subs, though.

Have you taken a look at makemkv (http://www.makemkv.com/)?
It decrypts and copies the main movie (with all audio and subtitle tracks) to an mkv container in a single step and it's free for DVDs.

[DMD]

This is true, however, one must consider an important question:

As far as forced subtitles, these are inserted nell'autoryng in two different ways,
A-independent stream
B-integrated stream

MakeMKV only works well with an independent stream.
As for the integrated stream, they are integrated into the main stream of the subtitles, you must follow a different procedure.

1 - to perform the procedure with completav MakeMKV selecting subtitles.

2 - demux the streams with MKVExtractorGui2

3-Drawing of the forced flow with BDSup2Sub

4 - remuxing with mkvmerge Streams



Performing the test I noticed that integrating the subtitles in srt format, instead sub / idx,
the quality of the subtitles is better.
What say you should follow the standard DVD (sub / idx) srt or you can enter without problems?


sub/idx Original DVD
http://img18.imageshack.us/img18/7374/screenshot020n.png (http://img18.imageshack.us/i/screenshot020n.png/)


srt
http://img576.imageshack.us/img576/8449/screenshot021v.png (http://img576.imageshack.us/i/screenshot021v.png/)



THANKS

[sneaker_ger]

Yes, too bad players don't allow to play only the forced part of a subtitle track in mkv, while they can do it for dvds.

[DMD]

Sorry for the off topic question, if you want to answer I posted here

http://forum.doom9.org/showthread.php?t=158023

Thanks

[derek0ray]

How to encrypt MKV files？ Does it has any mechanic for doing that?

[verydoomed]

I think its a good container but like a lot of newer things the hard ware is taking ages to catch up. I have a new Sony Tv that I can plug a usb stick into it and play back mpegs - avi and even .wmv but it won't play .mkv
So in short mkv is not of much use to me if I cant use it in a practical way - I have to convert it to something else.

[manolito]

Recently the German computer magazine c't stated that a couple of hardware manufacturers refuse to support MKV because they see it as a "hacker" container. But they mostly do support the same movie in a MP4 container.

You should try to just repack your movie into an MP4 container (no reencoding, maybe convert the audio to AAC) and check if your TV plays it...


Good luck
manolito

[marcusj0015]

What is the proper format of Matroska Metadata, and which tags are acceptable/what is the layout of the XML file for it to be compliant?

I *think* I found a list of tags, but I have NO idea about the XML layout.

http://www.matroska.org/technical/specs/tagging/othertagsystems/comparetable.html

[Music Fan]

Hi,
is there a way to keep just one extract of a MKV with MKVMerge GUI ?
I found several topics explaining how to split files in x parts but I'd like to keep just one part (to avoid to cut in x parts and throw away all unneeded parts).
I found the command line there ;
https://www.bunkus.org/videotools/mkvtoolnix/doc/mkvmerge.html#mkvmerge.description.split
example to keep 2 extracts separately ;
--split parts:00:01:20-00:02:45,00:05:50-00:10:30

or with a + to gather them in one file ;
--split parts:00:01:20-00:02:45,+00:05:50-00:10:30

As I'm not a huge command line fan, I'd like to make it with GUI if possible.
Does the "after timecodes" (or "by parts") box allow this ? If yes, what is the exact syntax (comma, dash ...) to specify debut and end timings ?
Thanks.;)

[Music Fan]

I answer to myself, it works with "by parts" :) ; simply put the time-codes like in command line (with the + if needed) ;
00:01:20-00:02:45,+00:05:50-00:10:30
It works with srt subtitles (when present in MKV) which stay synchronized with video.:)

[AlanHK]

Recently the German computer magazine c't stated that a couple of hardware manufacturers refuse to support MKV because they see it as a "hacker" container. But they mostly do support the same movie in a MP4 container.

You should try to just repack your movie into an MP4 container (no reencoding, maybe convert the audio to AAC) and check if your TV plays it...
I've got a 1-year-old Akai TV that plays files on USB.
It supports both MKV and MP4, but I have better luck with MKV.
Sometimes it says "unsupported file", but often just running the file through MKVmergeGUI, no reencoding, makes it playable.

I often do that anyway, only takes a few seconds.

[Music Fan]

I've got a 1-year-old Akai TV that plays files on USB.
It supports both MKV and MP4, but I have better luck with MKV.
Sometimes it says "unsupported file", but often just running the file through MKVmergeGUI, no reencoding, makes it playable.
That's probably due to header compression in the original MKV. Standalone players are rarely (if not never) compatible with header compression.
And when you run it through MKVmerge, this compression is removed (unless you specify to put it).

[Katie Boundary]

"advantages and disadvantages of Matroska over MP4"

[amayra]

"advantages and disadvantages of Matroska over MP4"

the most important softsub and multitrack