VobSub2SRT is a simple command line program to convert
.srt text subtitles by using OCR. It is based on code from the
MPlayer project - a really really great movie player. Some minor parts are
copied from ffmpeg/avutil headers. Tesseract is used as OCR software.
vobsub2srt is released under the GPL3+ license. The MPlayer code included is GPL2+ licensed.
The quality of the OCR depends on the text in the subtitles. Currently the code
does not use any preprocessing. But I’m currently looking into adding filters
and scaling options to improve the OCR. You can correct mistakes in the
files with a text editor or a special subtitle editor.
You need tesseract. You also need cmake and a gcc to build it. With Ubuntu 12.10 you can install the dependencies with
sudo apt-get install libtiff5-dev libtesseract-dev tesseract-ocr-eng build-essential cmake pkg-config
You should also install the tesseract data for the languages you want to use! Note that the support for tesseract 2 is deprecated and will be removed in the future!
./configure make sudo make install
This should install the program vobsub2srt to
/usr/local/bin. You can
uninstall vobsub2srt with
sudo make uninstall.
I recommend using the dynamic binary! However if you really need a static binary
you can add the flag
-DBUILD_STATIC=ON to the
./configure call. But be
aware that building static binaries can be quite troublesome. You need the
static library files for tesseract, libtill, libavutils, and for their
dependencies as well. On Ubuntu 12.04 the static libraries are only included in
the dev packages! You probably also need the Gold linker.
For Ubuntu 12.04 you need the following extra packages:
sudo apt-get install libleptonica-dev libpng12-dev libwebp-dev libgif-dev zlib1g-dev libjpeg-dev binutils-gold
If linking fails with undefined references then checking what other dependencies
your version of leptonica has is a good starting point. You can do this by
ldd /usr/lib/liblept.so (or whatever the path to leptonica is on your
system). Add those dependencies to
Ubuntu PPA and .deb packages
I have created a PPA (Personal Package Archive) to make installation on
Ubuntu easy. Simply add the PPA to your apt-get sources and run an update and
you can install the
sudo add-apt-repository ppa:ruediger-c-plusplus/vobsub2srt sudo apt-get update sudo apt-get install vobsub2srt
You can build a *.deb package (Debian/Ubuntu) with
make package. The package
is created in the
You can also create a source package and upload it to your own PPA by using the
UploadPPA.cmake. But this is only recommended for people experienced with
cmake and creating Debian packages.
Vobsub2srt contains a formula for Homebrew (a package manager for OS X). It can be installed by using the following commands:
brew install --all-languages tesseract brew install --HEAD https://github.com/ruediger/VobSub2SRT/raw/master/packaging/vobsub2srt.rb
An ebuild for Gentoo Linux is also available. You can make it available to emerge with the following steps
sudo mkdir -p /usr/local/portage/media-video/vobsub2srt/ wget https://github.com/ruediger/VobSub2SRT/raw/master/packaging/vobsub2srt-9999.ebuild sudo mv vobsub2srt-9999.ebuild /usr/local/portage/media-video/vobsub2srt/ cd /usr/local/portage/media-video/vobsub2srt/ sudo ebuild vobsub2srt-999.ebuild digest
You should be able to install vobsub2srt with
emerge vobsub2srt now. If you
want to use a newer version (3+) of tesseract you have to use layman.
See #13 for details.
vobsub2srt converts subtitles in VobSub (
.sub) format into subtitles
.srt format. VobSub subtitles consist of two or three files called
Filename.sub and optional
Filename.ifo. To convert subtitles
Filename being the file name of the subtitle files WITHOUT the
.sub). vobsub2srt writes the subtitles to a file called
If a subtitle file contains more than one language you can use the
parameter to set the correct language (Use
--langlist to find out about the
languages in the file). For some languages you might need to set the tesseract
language yourself (e.g., chi_tra/chi_sim for traditional or simplified chinese
characters). You can use
--tesseract-lang to do this. In most cases this
should however be autodetected.
If you want to dump the subtitles as images (e.g. to check for correct ocr) you
can use the
--help or read the manpage to get more information about the options of
Please submit bug reports or feature requests to the issue tracker on GitHub. If you do not have a GitHub account and feel uncomfortable creating one then feel free to send an e-mail to <firstname.lastname@example.org> instead.
If you have problems with a specific subtitle file then please check if it works in mplayer first. If it does not then please report the bug to mplayer as well and link to the mplayer bug report.
For bug reports please run
vobsub2srt with the
--verbose option and copy
and paste the full output to the bug report.
Most code is from the MPlayer project.
- Armin Häberling <email@example.com> wrote a patch to fix an issue with multiple instances of the same subtitle in result file (21af426)
- James Harris <firstname.lastname@example.org> wrote the formula for Homebrew (54f311d6)
- Leo Koppelkamm reported and fixed issue #5 and problems with long filenames (b903074c, 36ec8da, d3602d6)
- Till Korten <email@example.com> wrote the ebuild script (#13)
- Andreasf fixed missing libavutil include path (3a175eb, #15)
- Michal Gawlik fixed the overlapping issue (5b2ccabc55f, #29, #32)
- “bit” made sure no trailing whitespace are written to the SRT (3a59dc278abc2, #38)
- Baudouin Raoult for various fixes (028f742, #44, b722a03, #42, 7293ac2, #40)
- Justyn Butler added the y-threshold support (f873761, #43)
- James Laird-Wah added min-width/height support and fixed other issues (41c6844, #48, #46)
- Filirom1 fixed a minor issue (4ed58c2, #49)
- implement preprocessing (first step scaling. Code available in