Subtitling

• If you do your own subtitles
  Length and time, format, language, silence/background noise, more than one speaker, how long does subtitling take
  
  
• Autogenerated subtitles
  Editing needed

If you do your own subtitles

Subtitling moving images can be a challenge: when the text flows, no one notices it – but if something stands out, reading can become halted. On this page, you will find a short guide on what to think about when you create subtitles.

Length

• 2 lines max
• 37–42 characters (including spaces)

Time on screen

• 1 short line: 1.5–2 seconds
• 1 full line: 3 seconds
• 2 full lines: 5–6 seconds

Subtitles are presented in text blocks of 1–2 lines of text. A line should not exceed 42 characters (including spaces). That way, the text will fit on the screen and the viewer will be able to read it all and have time to look at what is shown on the screen.

A block of 2 lines needs to remain on screen for up to 6 seconds. If it is only one, shorter line, 2 seconds may be enough.

Format

Text that does not fit into one block needs to continue in a second block.

Do not use ellipses (…) to show that a sentence will continue in the next block. Avoid letting a subtitle hang over a shot change. Line breaks should be at logical points and ideally at a piece of punctuation like a full stop or comma.

Justification. Subtitles in English are normally centred, subtitles in Swedish are left-aligned.

Do not hyphenate words that do not fit in one line; instead, move the word to the following line.

Line arrangement. In order not to put too much strain on the eyes, the upper line should be shorter than the lower one:

Wrong:
This sentence is too long to
fit on a single line.

Correct:
This sentence is too
long to fit on a single line.

Please note that the above sentence is only intended as an illustration of line arrangement. Line breaks should always be inserted where natural breaks would occur and not in the middle of a phrase.

Language

Compress the text if needed, for example by opting for shorter words if possible (using suitable register) and deleting any non-essential content such as filler words. 

If you are subtitling video that largely consists of close-ups of the person talking, you need to stay closer to the actual speech and you should keep words that can be easily lip-read.

Abbreviations

It can be tempting to use abbreviations to compress the text, but they often have a negative effect on legibility. Write them in full if possible.

The SLU abbreviation EMA should be written in full: environmental assessment.

Symbols and numbers

• Do not use symbols, write the words in full: 70 euro, 10 per cent.
• Use digits to write numbers up to nine.
• Write dates in the format 1 May 2020.
• Do not abbreviate the names of months (Oct, Nov, etc.).
• Use a full stop for times: 08.07, 22.35.
• If you are only stating full hours, no colon is needed: 8­–17.

Silence and background noise

It is important to mark longer silences and background noises if they are relevant to understanding the video. Sometimes, music covers dialogue, for example between groups of people. In those cases, it is important to state that the dialogue in question is inaudible.

Silence and background noises should be marked with parentheses. Example: (inaudible dialogue).

More than one person talking

If you are subtitling a clip with more than one person talking, for example a panel debate, it must be clear to the viewer who is speaking. If the speakers' faces aren't clearly visible, indicate who is speaking by, for example, using a different colour for each speaker (make sure there is sufficient contrast) or using the speaker's initials to signal who is talking.

How long does subtitling take?

How long it takes to subtitle a video clip depends on the content, but expect it to take 5-10 times the duration of the clip.

Autogenerated subtitles

According to the Swedish Language Act, public authorities like SLU are required to use language that is ’cultivated, simple and comprehensible’. High quality is also a central part of SLU’s language policy.

The quality of autogenerated text is often not sufficient to meet these objectives. Poor-quality subtitles are not helpful for viewers, do not meet legal requirements and will not give a good impression of SLU.

Noisy environments with a lot of background noise will affect the quality of automatic/AI-generated subtitles. If the speaker has a strong accent or pronounced dialect, this can also affect the quality.

If you use automatic/AI-generated subtitles, you will need to review them to ensure sufficient quality. The originator of recorded material (person/unit) is responsible for the quality of subtitles.