SubRip is a software program for Windows which "rips" subtitles and their timings from video.
It is free software, released under the GNU GPL.
SubRip is also the name of the widely used and broadly compatible subtitle text file
format created by this software.
SubRip software Using optical character recognition, SubRip
can extract from live video, video files and DVDs, then record the extracted subtitles
and timings as a Subrip format text file.
It can optionally save the recognized subtitles as bitmaps for later subtraction from the
source video.
In practice, SubRip is configured with the correct codec for the video source, then trained
by the user on the specific text area, fonts, styles, colors and video processing requirements
to recognize subtitles.
After trial and fine tuning, SubRip can automatically extract subtitles for the whole video source
file during its playback.
SubRip records the beginning and end times and text for each subtitle in the output text
.srt file.
SubRip uses AviSynth to extract video frames from source video, and can rip subtitles from
all video files supported by that program.
SubRip text file format The SubRip file format, as reported on the
Matroska multimedia container format website, is "perhaps the most basic of all subtitle
formats."
SubRip files are named with the extension .srt, and contain formatted lines of plain
text in groups separated by a blank line.
Subtitles are numbered sequentially, starting at 1.
The timecode format used is hours:minutes:seconds,milliseconds with time units fixed to two zero-padded digits
and fractions fixed to three zero-padded digits.
The fractional separator used is the comma, since the program was written in France.
A numeric counter identifying each sequential subtitle
The time that the subtitle should appear on the screen, followed by --> and the time it
should disappear Subtitle text itself on one or more lines
A blank line containing no text, indicating the end of this subtitle
SubRip structure examples Plain
1 00:00:10,500 --> 00:00:13,000
Elephant's Dream
2 00:00:15,000 --> 00:00:18,000
At the left we can see...
With specific DVD rectangle positioning and styling
1 00:00:10,500 --> 00:00:13,000 X1:63 X2:223
Y1:43 Y2:58 Elephant's Dream
2 00:00:15,000 --> 00:00:18,000 X1:53 X2:303
Y1:438 Y2:453 At the left we can see...
Formatting Unofficially the format has very basic text
formatting, which can be either interpreted or passed through for rendering depending
on the processing application.
Formatting is derived from HTML tags for bold, italic, underline and color:
Bold – ... or {b} ... {/b} Italic – ... or {i} ... {/i}
Underline – ... or {u} ... {/u} Font color – <font color="color name or
#code"> ... Nested tags are allowed; some implementations
prefer whole-line formatting only.
Compatibility The SubRip .srt file format is supported by
most software video players listed in Comparison of video player software.
For Windows software video players that do not support subtitle playback directly, the
VSFilter DirectX filter displays SubRip and other subtitle formats.
The SubRip format is supported directly by many subtitle creation/editing tools, and
some hardware home media players.
In August 2008, YouTube added subtitle support to its Flash video player under the "Closed
Captioning" option - content producers can upload subtitles in SubRip format.
WebVTT A format originally called WebSRT was as of
October 2010 being specified by the Web Hypertext Application Technology Working Group for the
proposed HTML5 element.
It shared the .srt file extension and was "broadly based on" the SubRip format, but
was not fully compatible with SubRip.
The prospective format was later renamed WebVTT with the .vtt file extension.
The main differences are: WebVTT's first line starts with WEBVTT after
the optional UTF-8 byte order mark there is space for optional header data between
the first line and the first cue Timecode fractional values are separated by
a full stop instead of a comma Timecode hours are optional
The frame numbering/identification preceding the timecode is optional
Metadata frames identified by the word NOTE can be added
Only supports extended characters as UTF-8 CSS in a separate file defined in the companion
HTML document for C tags is used instead of the FONT tag
Support for the new format is limited but growing.
Google's Chrome and Microsoft's Internet Explorer 10 browsers support tags with .vtt
files for HTML5 videos already.
Firefox implemented WebVTT in its nightly builds, but initially it was not enabled by
default.
The feature had to be enabled in Firefox by going to the "about:config" page and setting
the value of "media.webvtt.enabled" to true.
YouTube began supporting WebVTT in April, 2013.
As of July 24th 2014, Mozilla has enabled WebVTT on Firefox by default.
Example of WebVTT format
WEBVTT Style:
::cue {color:#ffff} ##
Kind: captions
NOTE CSS style defined in header
NOTE Relative and percentage based positioning
NOTE Karaoke style split line
Text encoding The SubRip .srt file format really only supports
the Microsoft Windows text encoding default of CP-1252.
A Unicode byte order mark can be added to support any Unicode encoding with UTF-8 being
preferred for its compatibility with CP-1252.
However a number of embedded hardware-based players only have support for non-Unicode
fonts due to the licensing costs associated with the commercial fonts used.
SubRip .srt file encoding tools Software tools to encode .srt subtitle files
into video containers: MovieCaptioner – MovieCaptioner can both
create SRT files and import them as well as other formats, and can convert other formats
to SRT after importing them.
FFmpeg – FFmpgeg supports also the Subtitles Character Encoding Conversion
GPAC / MP4Box iSubtitle
XMedia Recode – XMedia Recode is a free All-In-One video- and audio converter tool
for Windows.
YAMB See also
Subtitles Closed Captioning
Timed Text Comparison of video player software, subtitle
ability Avidemux
List of free television software MicroDVD
SubStation Alpha Universal Subtitle Format
DirectVobSub is able to extract subtitles from a DVD without first extracting the files
from it.
Notes
References
External links Official website
".SRT SubRip file format specification".
Doom9.
Retrieved April 7, 2004.
"Derived from the SubRip source code" WebVTT Standard
Mozilla's developer page concerning WebVTT implementation
SubRip subtitle features and support in players – comparison of .srt feature handling in
a range of common players