subs(1) convert, join, split, and re-time subtitles


        subs [options] subfile [ subfile ... ]


-a coeff, -b time
a and b coefficients in linear transformation u=at+b, where t and u are src and dest times ( default(identity transform) is [a=1,b=0] ). -a can be set as ratio, f.ex. 23.9/25
-c codec
Use codec to write file. Run 'subs -h' for list of installed codecs.
Try to prolong duration of quickly disappearing text. 'Quickly' is less than 0.8 second per line of text.
-e command
Run perl code for each line of text in file. On each run, the text and time variables are initialized, and new values, if any, written to the file. The variables are used for:
subtitle text line
cue beginning
cue end
line number
number of lines
persistent data between runs

The -e option can be specified several times

Display help
Edit files in place ( makes backup in .bak files )
-j sec
Time interval between joins, seconds (default 2)
-o file
File to save processed subtitles (default out.sub)
Separate overlapped lines
-p t1 t2 or -P t2 t1
Set a control point, where t1 is time of a phrase spoken in the film and t2 is time when the same phrase as appears in the subtitle. Two points are required for deducing -a and -b coefficients; if only one point is specified, it is assumed that the other one is [0,0].

Times can be relative, f.ex. -p 01:00 +3.5 -p -20 1:00:00

Options -P and -p are the same except the argument sequence is reversed. -P is to be used when arguments to -p were typed manually and in wrong order.

-q t1 t2
Restrict changes, if any, in time span t1-t2. Word 'end' can be used as an alias to the end of the file. Default values are '0' and 'end'.
-r rate
Force frame-per-second rate for frame-based subs
-s time
Split in two parts by time
Be verbose
-z file.sub
Zip subtitle files so time information is read from file.sub, while text information is read from the input file(s).


The time format is either [[HH:]MM:]SS[.MSEC] or subtitle format-specific


Warning: -i is a great feature, but use it with certain caution.

If subtitles are shown too early ( 5 seconds):

  subs -i -b 5 file.sub

If subtitles are for a movie in 25 fps, need to be for 24 ( actual for frame-based formats only ).

  subs -i -a 24/25 file.sub

If subtitles start ok, but in 1 hour are late in 7 seconds:

  subs -i -p 0 0 -p 1:00:00 +7 file.sub

Join two parts with 15-second gap

  subs -o joined.sub -j 15 part1.sub part2.sub

Split in two after 50 minutes and half a second ( makes basename.1.sub and basename.2.sub ).

  subs -o basename.sub -s 50:00.5 toobig.sub

Remove closed caption-specific comments such as '[Sneezing]' or '[Music playing]'

  subs -e 's/[\s-]*\[.*\]\s*\n*//gs' sub.sub


Subtitles written as ".smi" format may differ from original.


Dmitry Karasik, <[email protected]>.