Video: Guidelines for Editing Auto-Generated Captions

Captions are the text of auditory information in a video, including words and non-speech sounds. Closed captions do not appear under a video by default but can be turned on by the viewer.

At the University of Minnesota, all uploaded videos should include captions that are:

• accurate
• complete
• well-placed 

After uploading videos to a platform with automatically-generated captions (e.g. YouTube, Kaltura, VoiceThread), follow this guide to proofread and edit your captions. 

• Depending on the platform you are using, you may allow other users to edit the captions. 
  • For more information, go to Kaltura: Manage Video Permissions.
• The accuracy of auto-generated captions depends on the quality of the audio. 
  • For support on improving audio, go to Prepare for Recording Audio Voiceovers.

In this article:

• Fix mistakes in spelling, add missing words, and fix punctuation.
• Adjust captions to align with the audio.
• Include speakers, non-speech sounds, and other auditory information.
• Review the video with captions turned on

Editing Closed Captions Guidelines

Fix mistakes in spelling, add missing words, and fix punctuation

Automatically-generated captions will miss some speech sounds and misinterpret what the speaker is saying.

• Ensure that all spoken words are correct and accurate.
• Do not paraphrase or censor what the speaker is saying.

Adjust captions to align with the audio

• Ensure each block of caption text is on-screen for between 1.5 and 6 seconds.
• Generally, use no more than two lines in each block of text.
  • Include a speaker identifier using a third line of captions.
• Consider how phrases break across lines.
  • Make lines of caption short and easy to read.
  • Aim for five to six words per line, or about 32 characters per line.
  • Break long caption lines into two shorter lines. Consider:
    • Individual word length: some words are longer than others.
    • Sentence cadence: make sure the sentence break is at a logical point where speech normally pauses.

Inappropriate (too long): 
She said I could order popcorn at the movie theatre.

Inappropriate (unnatural break):
She said I could order
popcorn at the movie theatre.

Appropriate:
She said I could order popcorn
at the movie theatre.

• Refer to the Described and Captioned Media Program (DCMP) Captioning Key section on Line Division for a more detailed explanation and examples.

Include speakers, non-speech sounds, and other auditory information

Speakers

• If there is more than one speaker, add speaker identifiers.
• If it is unclear who is speaking, add speaker identifiers.
• If the speaker's name is known, label it in parentheses.
• If there is back-and-forth conversation between speakers, give each speaker their own block of text.
      (Chee)
      Put the pumpkin on the table.

      (Darren)
      Can you hand me the carving knife?

• If names are unknown, use generic labels.
      (Professor)
      Turn to page 394.
• If it's clear who's speaking on screen, they do not need to be identified.
  • Use an angled bracket to identify the speaker.
    >Put the pumpkin on the table.
  • Use a double-angled bracket if the speaker changes.
    >>Can you hand me the carving knife?

Sounds

• Omit the sound's source if the source is visible on-screen.
• Put non-speech sounds in brackets on their own line.
      Example:
      [Applause with cheering]
• Include the sound's source description.
      Example:
      [Plane passing overhead]

Music

• Use objective words to describe music.
      Example:
      [intense percussive music]
• Caption lyrics verbatim.
• Caption the performer and song title, if known.
      Example:
      [Prince singing "Sometimes It Snows in April"]

Review the video with captions turned on

Check the quality and accuracy of caption lines and non-speech sounds in your video.