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Subtitled video

Many video professionals are unaware, or in denial of, the fact that video with subtitling also needs captioning if the video has a soundtrack. Subtitles are mistakenly assumed to be the same as captioning, or at least are deemed good enough. In fact, subtitles do not provide enough information for deaf and hard-of-hearing audiences.


Captioning and subtitling are different media with deceptively similar appearance.

  1. Captions are intended for deaf and hard-of-hearing audiences. The assumed audience for subtitling is hearing people who do not understand the language of dialogue.
  2. Captions move to denote who is speaking; subtitles are almost always set at bottom centre.
  3. Captions can explicitly state the speaker’s name:
    1. Cigarette Smoking Man:
    2. [MARTIN]
    3. >> Announcer:
  4. Captions notate sound effects and other dramatically significant audio. Subtitles assume you can hear the phone ringing, the footsteps outside the door, or a thunderclap.
  5. Subtitles are usually open. Captions are usually closed (i.e., require a decoder, usually built into television sets, or a seat-mounted display, as in the WGBH Rear Window system).
  6. Captions are usually in the same language as the audio. Subtitles are usually a translation.
  7. Subtitles also translate onscreen type in another language, e.g., a sign tacked to a door, a computer monitor display, a newspaper headline, or opening credits.
  8. Subtitles never mention the source language. A film with dialogue in multiple languages will feature continuous subtitles that never indicate that the source language has changed. (Or only dialogue in one language will be subtitled – Cf. Life Is Beautiful, where only the Italian is subtitled, not the German.)
  9. Captions tend to render the language of dialogue, transliterate the dialogue, or state the language:
  10. Captions ideally render all utterances. Subtitles do not bother to duplicate some verbal forms, e.g., proper names uttered in isolation (“Jacques!”), words repeated (“Help! Help! Help!”), song lyrics, phrases or utterances in the target language, or phrases the worldly hearing audience is expected to know (“Danke schön”).
  11. Captions render tone and manner of voice where necessary:
    1. whispering )
    3. [ Vincent, Narrating ]
  12. A subtitled program can be captioned (subtitles first, captions later). Captioned programs aren’t subtitled after captioning.

Advantages of online captioning

Online captioning may have a few advantages when it comes to captioning a subtitled production.

If the subtitling is open (e.g., burned into the video) and does not use any player features, then it becomes easy to separate captions from subtitles. The two media don’t have to fight for limited space within the frame. Use the player’s closed captioning; the resulting file can be the only one distributed, since viewers can opt into the captioning.

Or, if separation of captions and subtitles within the frame isn’t an issue, add further burned-in open captions that are typographically distinct from the subtitles. That video would likely have to be separate from the uncaptioned feed to avoid “distracting” sensitive hearing viewers.

We were unable to find examples of online video whose subtitles and captions were both rendered by player features – that is, both through SMIL, SAMI, RealText, QTtext, or other technology. Multiple simultaneous streams of text – whether used for captions or subtitles – may be impossible in current players, particularly given the fact that subtitles and captions will have different in and out times. A number of real-world test videos are required to develop best practices.