Two Rows of Text…

Two Rows of Text…

Subtitling from start to finish

Subtitling in television is used mainly for two things, to make foreign language material accessible and to aid hard-of-hearing people. Subtitling for translation allows a broadcaster to reach multiple language target audiences. The viewer can select the language to receive and made visible on the screen. For heard-of-hearing people subtitling allows them to follow television. Therefore this is often a legal requirement in many countries.

Why subtitling instead of audio dubbing?

The overwhelming advantage of subtitling over dubbing is cost. Subtitling is many times cheaper per language to produce than alternative language audio tracks. Also, a new subtitling language can easily be added to a whenever needed, even after all material preparations are done.


Subtitling is usually not an exact translation, because difference between countries and languages often require additional information to understand the original content. And subtitling often compresses the language to fit the same information spoken into as little text as possible, to not unnecessarily distract the viewer.

How does subtitling work?

Subtitling is comprised of two parts – preparation and transmission.


The preparation of the individual subtitle files, along with the timecode required to synchronise the subtitle with the video, is done ahead of transmission, either by trained in-house subtitle translators – or more often these days subcontracted to specialist subtitle preparation companies. The files are delivered to the transmission site in a format normally defined by the broadcaster and stored until needed for transmission.


Subtitle transmission is an automated process using standard Cavena equipment. The Cavena equipment interfaces to station planning and automation systems to receive programme information and trigger commands. The transmission units then synchronise the subtitles for play-out using the timecode read from the video signal. Subtitles are output in one or more formats depending on transmission platform.


Cavena also provide subtitle transcoding solutions for conversion between transmission formats. This is integrated into our transmission products, so our STU play-out unit can switch between timecode synchronised subtitle file play-out and transcoding from one subtitling format into another. STU also supports live subtitling inputs.

What equipment is required?

This all depends on what is installed or what is to be installed, and the technology used for distribution of TV and subtitles. At the play-out centre, the main subtitle components are;


  • Storage, QC check and archiving with Cavena SAM
  • Transmission control and automation interface with Cavena STC.
  • Playout of subtitles with Cavena STU.
  • SDI subtitle insertion.


For preparation, the Cavena TEMPO is an advanced and flexible PC based system with all of the features needed to create high quality subtitle files.


Cavena is specialised in subtitling, we have assisted many customers when it comes to design and configuration of cost effective subtitling solutions and installations, including back up installations. Time code or transcode? Cavena can assist you with answers.

Why should you choose Cavena?

Cavena is one of the worlds longest established and most experienced subtitling systems providers, and can supply the complete range of subtitling equipment.


Cavena has the experience, the background and the know-how to put together the most cost effective, flexible and highly reliable system to allow your customers to grow their viewer numbers.


Cavena systems are in constant use worldwide with a large number of broadcasters with widely differing requirements, so we are able to specify exactly what your customers will need to service their requirements.


At Cavena, we also take great pride in our product support, ensuring a very high uptime. Cavena systems are also very flexible, allowing new languages and channels to be added with minimal disruption.