How to do subtitling?

Subtitling has become essential for reading a video and understanding it. Nowadays, to view a video, we often tend to cut the sound and read the subtitles, because it rests from the ambient noise. Then, depending on where you are, cutting the audio is inevitable. Finally, quality subtitles are ideal for conveying your brand image and message, as well as for people with disabilities, the deaf and hard of hearing for example. Subtitles should be accurate and clear, free of spelling errors, and well matched to what is being said in the video. So, how does it work? How do we do subtitling?

In summary

1. What is subtitling? The Guide

1.1. Definition

1.2. Constraints

2. How to subtitle a video? The steps

2.1. Transcription or speech-to-text: what is it?

2.2. Synchronization with time-codes

2.3. Translation and writing of subtitles

2.4. Preview and corrections

2.5. Displaying subtitles on your video


1. What is subtitling? The Guide

Subtitling is the text that appears on each frame of a video, film or cartoon. It is the translation of the dialogue spoken by the characters and the narrator. Subtitling has become essential for various reasons, here is everything you need to know about this process.

1.1. Definition

Subtitling a video has a set of very specific technical rules. It is an audiovisual translation where time and space limitations directly affect the result. It is a translation that is subordinated to the image and sound according to a defined time.

1.2. Constraints

To subtitle, you have a space that displays the translation.

Here are the constraints to respect:

  • 2 lines of subtitles centered on the lower part of the screen;
  • 35 to 40 characters per line which are symbols, letters, spaces, etc.
  • So a complete subtitle has 2 lines of 70 to 80 characters ;
  • Its display time is between 1 and 6 seconds.

These numbers are defined from a link between the display duration of a subtitle and the maximum number of characters it holds so that the readability is impeccable. Indeed, an average reading is estimated at 3 words per second, so the reading of a subtitle of 2 lines and about 12 words is estimated at 4 seconds. So, if the time is reduced, the number of characters must necessarily be reduced.

Moreover, since the subtitle only stays on the screen for a few seconds, it must be quickly understandable. Therefore, a translation must be faithful to the original dialogue and unobtrusive.

2. How to subtitle a video ? The steps 

Discover the steps to subtitle your video.

2.1.Transcription or speech-to-text: what is it? 

Transcription involves listening to a recording and transcribing it into written form. It is also called speech-to-text. This means that the linguist must understand what is being said in order to write it down accurately. A transcription takes into account the entirety of an audio file such as a podcast, for example, or a video, regardless of its format. Are you familiar with the Vlog format? This format is just perfect for memorizing moments.

Nevertheless, the transcription must be of high quality and natural to read. To do this, there are rules to follow, here they are:

  • The transcription must follow the same structure as the common language;
  • The meaning of the sentence must be consistent in the cutting of the subtitle and the calibration of the 2 lines, the cut must be natural;
  • In the dialogue, each intervention is transcribed on a new line and it begins with a dash;
  • If off-camera songs or sounds exist, the text is transcribed in italics;
  • The use of capital letters should be reserved for titles only and used sparingly.

The goal is to achieve a consistent result and easy-to-read subtitles. The viewer should not be aware that they are reading while integrating the image and sound.


2.2. Synchronization with time-codes

Synchronization is the part where the time when the subtitles appear and disappear from the screen is calculated.

Subtitles must be synchronized with the sound. Other elements to consider are:

  • The length of the subtitle;
  • The changes of angles and camera shots.

Indeed, at each change of camera shots, the viewer automatically lowers his gaze to reread the subtitle, hence the importance of synchronizing these moments. For this, the time code is used.

Time code

A time code is given in hours, minutes, seconds and images to identify the beginning and end of each line. Indeed, the rate is twenty-five frames per second in video, from this observation, it is easy to mark precisely each sentence. The subtitle must appear at the very moment when the speech begins.
And, while respecting the 6-second limit, it is possible to leave the subtitle visible after the line if it is too short compared to the length of the sentence spoken.
In addition, the subtitle should be removed at the next shot, so that the viewer does not read the same subtitle at the next frame.





Number of characters

For each line, we define the number of characters that present the subtitle. It is usually 12 characters per second of image. It consists of letters and spaces, spread over 2 superimposed lines so that the translator does not have to read the image from end to end. This way, the translator knows the length of the line to be subtitled.

2.3.Translating and writing subtitles

The translation of the subtitles is an adaptation of the source language adjusted to the number of characters defined by the length of the subtitle. With the help of spotting, the translator adopts the spoken dialogue of one language into written dialogue in another language. In order to do this, different parameters have to be taken into consideration:

  • The native language;
  • The customs and culture of the latter;
  • The expressions of the language region;
  • Etc.

For this, an intelligent translation must be performed. To save time, machine translation is necessary, but proofreading by a native translator is a must. The understanding of the dialogue is at stake. The culture of the country of origin must be understood by the culture of the country of reception.

2.4. Preview and corrections

During the preview, the viewing of the subtitles with image and sound is tested. A check is made to ensure that all the parameters are respected and that the subtitles can be read in a completely natural way.

It is during this stage that:

  • The text is corrected;
  • As well as its location;
  • The time of its appearance ;
  • And of its disappearance.

2.5. Displaying subtitles on your video

Once your subtitles are perfectly written, translated and synchronized, the next step is to display your subtitles on your video.

You have two options, depending on the medium on which you want to broadcast your video:

  • embedding the subtitles in the video (also called “burn” step): the subtitles will then be inseparable from the video, they will be somehow merged with your video. The advantage is that you can be sure that your subtitled video will be readable on all platforms, and that the graphic charter of your subtitles will be preserved! The disadvantage is that you will have one video per subtitling language.
  • the use of the subtitle file (in .srt format for example): this subtitle file in text format must be added to your broadcasting platform with the video. The subtitles are then dissociated from the video. The users have to activate / deactivate the subtitles by themselves, according to the desired subtitling language. The disadvantage is that some broadcasting platforms such as Instagram for example do not allow the add of subtitle files. In addition, you will have less flexibility in the graphic design of your subtitles.

Did this guide to subtitling enlighten you? Are you looking for a professional result? Then entrust the subtitling of your training, corporate or awareness video to the collaborative platform Eolementhe! Thanks to artificial intelligence and the help of translators, your video is edited, translated and subtitled in no time. Automation and human proofreading are the winning combination of this fast, cheap and easy to use process!