This program extracts specific parts from a
Matroska(TM)
file to other useful formats. The first argument is the name of the source file which must be a
Matroska(TM)
file.
All other arguments either switch to a certain extraction mode, change options for the currently active mode or specify what to extract into which file. Multiple modes can be used in the same invocation of mkvextract allowing the extraction of multiple things in a single pass. Most options can only be used in certain modes with a few options applying to all modes.
Currently supported is the extraction of
tracks,
tags,
attachments,
chapters,
CUE sheets,
timestamps
and
cues.
Common options
The following options are available in all modes and only described once in this section.
-f, --parse-fully
-
Sets the parse mode to 'full'. The default mode does not parse the whole file but uses the meta seek elements for locating the required elements of a source file. In 99% of all cases this is enough. But for files that do not contain meta seek elements or which are damaged the user might have to use this mode. A full scan of a file can take a couple of minutes while a fast scan only takes seconds.
--command-line-charset character-set
-
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.
--output-charset character-set
-
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.
-r, --redirect-output file-name
-
Writes all messages to the file
file-name
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
--output-charset
is honored.
--flush-on-close
-
Tells the program to flush all data cached in memory to storage when closing files opened for writing. This can be used to prevent data loss on power outages or to circumvent certain problems in the operating system or drivers. The downside is that multiplexing will take longer as mkvmerge will wait until all data has been written to the storage before exiting. See issues #2469 and #2480 on the MKVToolNix bug tracker for in-depth discussions on the pros and cons.
--ui-language code
-
Forces the translations for the language
code
to be used (e.g. 'de_DE' for the German translations). Entering 'list' as the
code
will cause the program to output a list of available translations.
--abort-on-warnings
-
Tells the program to abort after the first warning is emitted. The program's exit code will be 1.
--debug topic
-
Turn on debugging for a specific feature. This option is only useful for developers.
--engage feature
-
Turn on experimental features. A list of available features can be requested with
mkvextract --engage list. These features are not meant to be used in normal situations.
--gui-mode
-
Turns on GUI mode. In this mode specially-formatted lines may be output that can tell a controlling GUI what's happening. These messages follow the format '#GUI#message'. The message may be followed by key/value pairs as in '#GUI#message#key1=value1#key2=value2...'. Neither the messages nor the keys are ever translated and always output in English.
-v, --verbose
-
Be verbose and show all the important
Matroska(TM)
elements as they're read.
-h, --help
-
Show usage information and exit.
-V, --version
-
Show version information and exit.
@options-file.json
-
Reads additional command line arguments from the file
options-file. For a full explanation on the supported formats for such files see the section called "Option files" in the
mkvmerge(1)
man page.
Track extraction mode
Syntax:
mkvextract source-filename tracks [options] TID1:dest-filename1 [TID2:dest-filename2 ...]
The following command line options are available for each track in the 'tracks' extraction mode. They have to appear in front of the track specification (see below) they should be applied to.
-c character-set
-
Sets the character set to convert the next text subtitle track to. Only valid if the next track ID targets a text subtitle track. It defaults to UTF-8.
--blockadd level
-
Keep only the BlockAdditions up to this level. The default is to keep all levels. This option only affects certain kinds of codecs like WAVPACK4.
--cuesheet
-
Causes
mkvextract(1)
to extract a
CUE
sheet from the chapter information and tag data for the following track into a file whose name is the track's output name with '.cue' appended to it.
--raw
-
Extracts the raw data into a file without any container data around it. Unlike the
--fullraw
flag this flag does not cause the contents of the
CodecPrivate
element to be written to the file. This mode works with all
CodecIDs, even the ones that
mkvextract(1)
doesn't support otherwise, but the resulting files might not be usable.
--fullraw
-
Extracts the raw data into a file without any container data around it. The contents of the
CodecPrivate
element will be written to the file first if the track contains such a header element. This mode works with all
CodecIDs, even the ones that
mkvextract(1)
doesn't support otherwise, but the resulting files might not be usable.
TID:outname
-
Causes extraction of the track with the ID
TID
into the file
outname
if such a track exists in the source file. This option can be given multiple times. The track IDs are the same as the ones output by
mkvmerge(1)'s
--identify
option.
Each output name should be used only once. The exception are RealAudio and RealVideo tracks. If you use the same name for different tracks then those tracks will be saved in the same file. Example:
-
$ mkvextract input.mkv tracks 0:video.h264 2:output-two-vobsub-tracks.idx 3:output-two-vobsub-tracks.idx
Attachments extraction mode
Syntax:
mkvextract source-filename attachments [options] AID1:outname1 [AID2:outname2 ...]
AID:outname
-
Causes extraction of the attachment with the ID
AID
into the file
outname
if such an attachment exists in the source file. If the
outname
is left empty then the name of the attachment inside the source
Matroska(TM)
file is used instead. This option can be given multiple times. The attachment IDs are the same as the ones output by
mkvmerge(1)'s
--identify
option.
Chapters extraction mode
Syntax:
mkvextract source-filename chapters [options] output-filename.xml
-s, --simple
-
Exports the chapter information in the simple format used in the
OGM
tools (CHAPTER01=..., CHAPTER01NAME=...). In this mode some information has to be discarded. Default is to output the chapters in
XML
format.
--simple-language language
-
If the simple format is enabled then
mkvextract(1)
will only output a single entry for each chapter atom encountered even if a chapter atom contains more than one chapter name. By default
mkvextract(1)
will use the first chapter name found for each atom regardless of its language.
Using this option allows the user to determine which chapter names are output if atoms contain more than one chapter name. The
language
parameter must be an ISO 639-1 or ISO 639-2 code.
The chapters are written to specified output file. By default the
XML
format understood by
mkvmerge(1)
is used. If no chapters are found in the file, the output file is not created.
Tags extraction mode
Syntax:
mkvextract source-filename tags [options] output-filename.xml
The tags are written to specified output file in the
XML
format understood by
mkvmerge(1). If no tags are found in the file, the output file is not created.
Cue sheet extraction mode
Syntax:
mkvextract source-filename cuesheet [options] output-filename.cue
The cue sheet is written to specified output file. If no chapters or tags are found in the file, the output file is not created.
Timestamp extraction mode
Syntax:
mkvextract source-filename timestamps_v2 [options] TID1:dest-filename1 [TID2:dest-filename2 ...]
TID:outname
-
Causes extraction of the timestamps for the track with the ID
TID
into the file
outname
if such a track exists in the source file. This option can be given multiple times. The track IDs are the same as the ones output by
mkvmerge(1)'s
--identify
option.
Example:
-
$ mkvextract input.mkv timestamps_v2 1:ts-track1.txt 2:ts-track2.txt
Cues extraction mode
Syntax:
mkvextract source-filename cues [options] TID1:dest-filename1 [TID2:dest-filename2 ...]
TID:dest-filename
-
Causes extraction of the cues for the track with the ID
TID
into the file
outname
if such a track exists in the source file. This option can be given multiple times. The track IDs are the same as the ones output by
mkvmerge(1)'s
--identify
option and not the numbers contained in the
CueTrack
element.
The format output is a simple text format: one line per
CuePoint
element with
key=value
pairs. If an optional element is not present in a
CuePoint
(e.g.
CueDuration) then a dash will be output as the value.
Example:
-
timestamp=00:00:13.305000000 duration=- cluster_position=757741 relative_position=11
The possible keys are:
timestamp
-
The cue point's timestamp with nanosecond precision. The format is
HH:MM:SS.nnnnnnnnn. This element is always set.
duration
-
The cue point's duration with nanosecond precision. The format is
HH:MM:SS.nnnnnnnnn.
cluster_position
-
The absolute position in bytes inside the
Matroska(TM)
file where the cluster containing the referenced element starts.
-
Note
Inside the
Matroska(TM)
file the
CueClusterPosition
is relative to the segment's data start offset. The value output by
mkvextract(1)'s cue extraction mode, however, contains that offset already and is an absolute offset from the beginning of the file.
relative_position
-
The relative position in bytes inside the cluster where the
BlockGroup
or
SimpleBlock
element the cue point refers to starts.
-
Note
Inside the
Matroska(TM)
file the
CueRelativePosition
is relative to the cluster's data start offset. The value output by
mkvextract(1)'s cue extraction mode, however, is relative to the cluster's ID. The absolute position inside the file can be calculated by adding
cluster_position
and
relative_position.
Example:
-
$ mkvextract input.mkv cues 1:cues-track1.txt 2:cues-track2.txt
EXAMPLES
Extracting both chapters and tags in their respective
XML
formats at the same time:
-
$ mkvextract movie.mkv chapters movie-chapters.xml tags movie-tags.xml
Extracting a couple of tracks and their respective timestamps at the same time:
-
$ mkvextract "Another Movie.mkv" tracks 0:video.h265 "1:main audio.aac" "2:director's comments.aac" timestamps_v2 "0:timestamps video.txt" "1:timestamps main audio.txt" "2:timestamps director's comments.txt"
Extracting chapters in the Ogg/OGM format and re-encoding a text subtitle track to another character set:
-
$ mkvextract "My Movie.mkv" chapters --simple "My Chapters.txt" tracks -c MS-ANSI "2:My Subtitles.srt"
TEXT FILES AND CHARACTER SET CONVERSIONS
For an in-depth discussion about how all tools in the MKVToolNix suite handle character set conversions, input/output encoding, command line encoding and console encoding please see the identically-named section in the
mkvmerge(1)
man page.
OUTPUT FILE FORMATS
The decision about the output format is based on the track type, not on the extension used for the output file name. The following track types are supported at the moment:
A_AAC/MPEG2/*, A_AAC/MPEG4/*, A_AAC
-
All
AAC
files will be written into an
AAC
file with
ADTS
headers before each packet. The
ADTS
headers will not contain the deprecated emphasis field.
A_AC3, A_EAC3
-
These will be extracted to raw
AC-3
files.
A_ALAC
-
ALAC
tracks are written to
CAF
files.
A_DTS
-
These will be extracted to raw
DTS
files.
A_FLAC
-
FLAC
tracks are written to raw
FLAC
files.
A_MPEG/L2
-
MPEG-1 Audio Layer II streams will be extracted to raw
MP2
files.
A_MPEG/L3
-
These will be extracted to raw
MP3
files.
A_OPUS
-
Opus(TM)
tracks are written to
OggOpus(TM)
files.
A_PCM/INT/LIT, A_PCM/INT/BIG
-
Raw
PCM
data will be written to a
WAV
file. Big-endian integer data will be converted to little-endian data in the process.
A_REAL/*
-
RealAudio(TM)
tracks are written to
RealMedia(TM)
files.
A_TRUEHD, A_MLP
-
These will be extracted to raw
TrueHD/MLP
files.
A_TTA1
-
TrueAudio(TM)
tracks are written to
TTA
files. Please note that due to
Matroska(TM)'s limited timestamp precision the extracted file's header will be different regarding two fields:
data_length
(the total number of samples in the file) and the
CRC.
A_VORBIS
-
Vorbis audio will be written into an
OggVorbis(TM)
file.
A_WAVPACK4
-
WavPack(TM)
tracks are written to
WV
files.
S_HDMV/PGS
-
PGS
subtitles will be written as
SUP
files.
S_HDMV/TEXTST
-
TextST
subtitles will be written as a special file format invented for
mkvmerge(1)
and
mkvextract(1).
S_KATE
-
Kate(TM)
streams will be written within an
Ogg(TM)
container.
S_TEXT/SSA, S_TEXT/ASS, S_SSA, S_ASS
-
SSA
and
ASS
text subtitles will be written as
SSA/ASS
files respectively.
S_TEXT/UTF8, S_TEXT/ASCII
-
Simple text subtitles will be written as
SRT
files.
S_VOBSUB
-
VobSub(TM)
subtitles will be written as
SUB
files along with the respective index files, as
IDX
files.
S_TEXT/USF
-
USF
text subtitles will be written as
USF
files.
S_TEXT/WEBVTT
-
WebVTT
text subtitles will be written as
WebVTT
files.
V_MPEG1, V_MPEG2
-
MPEG-1
and
MPEG-2
video tracks will be written as
MPEG
elementary streams.
V_MPEG4/ISO/AVC
-
H.264
/
AVC
video tracks are written to
H.264
elementary streams which can be processed further with e.g.
MP4Box(TM)
from the
GPAC(TM)
package.
V_MPEG4/ISO/HEVC
-
H.265
/
HEVC
video tracks are written to
H.265
elementary streams which can be processed further with e.g.
MP4Box(TM)
from the
GPAC(TM)
package.
V_MS/VFW/FOURCC
-
Fixed
FPS
video tracks with this
CodecID
are written to
AVI
files.
V_REAL/*
-
RealVideo(TM)
tracks are written to
RealMedia(TM)
files.
V_THEORA
-
Theora(TM)
streams will be written within an
Ogg(TM)
container
V_VP8, V_VP9
-
VP8
/
VP9
tracks are written to
IVF
files.
Tags
-
Tags are converted to a
XML
format. This format is the same that
mkvmerge(1)
supports for reading tags.
Attachments
-
Attachments are written to the output file as they are. No conversion whatsoever is done.
Chapters
-
Chapters are converted to a
XML
format. This format is the same that
mkvmerge(1)
supports for reading chapters. Alternatively a stripped-down version can be output in the simple
OGM
style format.
Timestamps
-
Timestamps are first sorted and then output as a timestamp v2 format compliant file ready to be fed to
mkvmerge(1). The extraction to other formats (v1, v3 and v4) is not supported.
EXIT CODES
mkvextract(1)
exits with one of three exit codes:
-
•
0
-- This exit code means that extraction has completed successfully.
-
•
1
-- In this case
mkvextract(1)
has output at least one warning, but extraction did continue. A warning is prefixed with the text 'Warning:'. Depending on the issues involved the resulting files might be ok or not. The user is urged to check both the warning and the resulting files.
-
•
2
-- This exit code is used after an error occurred.
mkvextract(1)
aborts right after outputting the error message. Error messages range from wrong command line arguments over read/write errors to broken files.
ENVIRONMENT VARIABLES
mkvextract(1)
uses the default variables that determine the system's locale (e.g.
LANG
and the
LC_*
family). Additional variables:
MKVEXTRACT_DEBUG, MKVTOOLNIX_DEBUG and its short form MTX_DEBUG
-
The content is treated as if it had been passed via the
--debug
option.
MKVEXTRACT_ENGAGE, MKVTOOLNIX_ENGAGE and its short form MTX_ENGAGE
-
The content is treated as if it had been passed via the
--engage
option.
SEE ALSO
mkvmerge(1),
mkvinfo(1),
mkvpropedit(1),
mkvtoolnix-gui(1)
WWW
The latest version can always be found at
m[blue]the MKVToolNix homepagem[][1].
AUTHOR
Moritz Bunkus <moritz@bunkus.org>
-
Developer
NOTES
- 1.
-
the MKVToolNix homepage
-
https://mkvtoolnix.download/