file and modifies some of its properties\&. Then it writes those modifications to the existing file\&. Among the properties that can be changed are the segment information elements (e\&.g\&. the title) and the track headers (e\&.g\&. the language code, \'default track\' flag or the name)\&.
.PP
Options:
.PP
\fB\-l\fR, \fB\-\-list\-property\-names\fR
.RS4
Lists all known and editable property names, their type (string, integer, boolean etc) and a short description\&. The program exits afterwards\&. Therefore the
\fIsource\-filename\fR
parameter does not have to be supplied\&.
.RE
.PP
\fB\-p\fR, \fB\-\-parse\-mode\fR\fImode\fR
.RS4
Sets the parse mode\&. The parameter \'\fImode\fR\' can either be \'fast\' (which is also the default) or \'full\'\&. The \'fast\' 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 se the \'full\' parse mode\&. A full scan of a file can take a couple of minutes while a fast scan only takes seconds\&.
.RE
.PP
Actions:
.PP
\fB\-e\fR, \fB\-\-edit\fR\fIselector\fR
.RS4
Sets the
Matroska(TM)
file section (segment information or a certain track\'s headers) that all following
add,
set
and
delete
actions operate on\&. This option can be used multiple times in order to make modifications to more than one element\&.
.sp
See the section about
edit selectors
for a full description of the syntax\&.
.RE
.PP
\fB\-a\fR, \fB\-\-add\fR\fIname\fR=\fIvalue\fR
.RS4
Adds a property
\fIname\fR
with the value
\fIvalue\fR\&. The property will be added even if such a property exists already\&. Note that most properties are unique and cannot occur more than once\&.
.RE
.PP
\fB\-s\fR, \fB\-\-set\fR\fIname\fR=\fIvalue\fR
.RS4
Sets all occurences of the property
\fIname\fR
to the value
\fIvalue\fR\&. If no such property exists then it will be added\&.
.RE
.PP
\fB\-d\fR, \fB\-\-delete\fR\fIname\fR
.RS4
Deletes all occurences of the property
\fIname\fR\&. Note that some properties are required and cannot be deleted\&.
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
\fB\-\-output\-charset\fR
is honored\&.
.RE
.PP
\fB\-\-ui\-language\fR\fIcode\fR
.RS4
Forces the translations for the language
\fIcode\fR
to be used (e\&.g\&. \'de_DE\' for the German translations)\&. It is preferable to use the environment variables
\fILANG\fR,
\fILC_MESSAGES\fR
and
\fILC_ALL\fR
though\&. Entering \'list\' as the
\fIcode\fR
will cause
\fBmkvextract\fR(1)
to output a list of available translations\&.
.RE
.PP
\fB\-v\fR, \fB\-\-verbose\fR
.RS4
Be verbose and show all the important
Matroska(TM)
elements as they\'re read\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS4
Show usage information and exit\&.
.RE
.PP
\fB\-V\fR, \fB\-\-version\fR
.RS4
Show version information and exit\&.
.RE
.PP
\fB@\fRoptions\-file
.RS4
Reads additional command line arguments from the file
\fIoptions\-file\fR\&. Lines whose first non\-whitespace character is a hash mark (\'#\') 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\&.
.sp
The command line \'\fBmkvpropedit source\&.mkv \-\-edit track:a2 \-\-set title=Comments\fR\' could be converted into the following option file:
file section (segment information or a certain track\'s headers) that all following
add,
set
and
delete
actions operate on\&. This stays valid until the next
\fB\-\-edit\fR
option is found\&. The argument to this option is called the edit selector\&.
.SS"Segment information"
.PP
The segment information can be selected with one of these three words: \'info\', \'segment_info\' or \'segmentinfo\'\&. It contains properties like the segment title or the segment
UID\&.
.SS"Track headers"
.PP
Track headers can be selected with a slightly more complex selector\&. All variations start with \'track:\'\&. The track header properties include elements like the language code, \'default track\' flag or the track\'s name\&.
.PP
\fBtrack:\fR\fIn\fR
.RS4
If the parameter
\fIn\fR
is a number then the
\fIn\fRth track will be selected\&. The track order is the same that
\fBmkvmerge\fR(1)\'s
\fB\-\-identify\fR
option outputs\&.
.RE
.PP
\fBtrack:\fR\fIt\fR\fIn\fR
.RS4
If the parameter starts with a single character
\fIt\fR
followed by a
\fIn\fR
then the
\fIn\fRth track of a specific track type will be selected\&. The track type parameter
\fIt\fR
must be one of these fourc characters: \'a\' for an audio track, \'b\' for a button track, \'s\' for a subtitle track and \'v\' for a video track\&. The track order is the same that
\fBmkvmerge\fR(1)\'s
\fB\-\-identify\fR
option outputs\&.
.RE
.PP
\fBtrack:\fR=\fIuid\fR
.RS4
If the parameter starts with a \'=\' followed by a number
\fIuid\fR
then the track whose track
UID
element equals this
\fIuid\fR\&. Track
UIDs
can be obtained with
\fBmkvinfo\fR(1)\&.
.RE
.PP
\fBtrack:\fR@\fInumber\fR
.RS4
If the parameter starts with a \'@\' followed by a number
\fInumber\fR
then the track whose track number element equals this
\fInumber\fR\&. Track number can be obtained with
\fBmkvinfo\fR(1)\&.
.RE
.SS"Notes"
.PP
Due to the nature of the track edit selectors it is possible that several selectors actually match the same track headers\&. In such cases all actions for those edit selectors will be combined and executed in the order in which they\'re given on the command line\&.
.SH"EXAMPLES"
.PP
The following example edits a file called \'movie\&.mkv\'\&. It sets the segment title and modifies the language code of an audio and a subtitle track\&. Note that this example can be shortened by leaving out the first
\fB\-\-edit\fR
option because editing the segment information element is the default for all options found before the first
has output at least one warning, but the modification 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\&.
