Informations- og kommunikationsteknologi med mulighed for video

Krav for websteder og mobilapplikationer

• 7.1.1 Captioning playback

  Where ICT displays video with synchronized audio, it shall have a mode of operation to display the available captions. Where closed captions are provided as part of the content, the ICT shall allow the user to choose to display the captions.

  NOTE 1: Captions may contain information about timing, colour and positioning. This caption data is necessary for caption users. Timing is used for caption synchronization. Colour can be used for speaker identification. Position can be used to avoid obscuring important information.

  NOTE 2: If a Braille device is connected, the ICT should provide an option to display captions on the Braille device.

  NOTE 3: Clause 7.1.1 refers to the ability of the player to display captions. Clauses 9.1.2.2, 10.1.2.2 and 11.1.2.2 refer to the provision of captions for the content (the video).

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.1.2 Captioning synchronization

  Where ICT displays captions, the mechanism to display captions shall preserve synchronization between the audio and the corresponding captions as follows:

  • Captions in recorded material: within 100 ms of the time stamp of the caption.
  • Live captions: within 100 ms of the availability of the caption to the player.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.1.3 Preservation of captioning

  Where ICT transmits, converts or records video with synchronized audio, it shall preserve caption data such that it can be displayed in a manner consistent with clauses 7.1.1 and 7.1.2.

  Additional presentational aspects of the text such as screen position, text colours, text style and text fonts may convey meaning, based on regional conventions. Altering these presentational aspects could change the meaning and should be avoided wherever possible.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.1.4 Captions characteristics

  Where ICT displays captions, it shall provide a way for the user to adapt the displayed characteristics of captions to their individual requirements, except where the captions are displayed as unmodifiable characters.

  NOTE 1: Defining the background and foreground colour of subtitles, font type, size opacity of the background box of subtitles, and the contour or border of the fonts can contribute to meeting this requirement.

  NOTE 2: Subtitles that are bitmap images are examples of unmodifiable characters.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.1.5 Spoken subtitles

  Where ICT displays video with synchronized audio, it shall have a mode of operation to provide a spoken output of the available captions, except where the content of the displayed captions is not programmatically determinable.

  NOTE 1: Being able to manage speech output range for spoken subtitles independently from general ICT speech is preferable for most users. That is possible when the audio file with spoken subtitle is delivered in a separate audio track and mixed in the end users device.

  NOTE 2: Presenting the separate audio track with spoken subtitles in synchronization with the displayed subtitles/captions improves understandability of the subtitles.

  NOTE 3: Providing subtitles/captions as separate text-streams, facilitates converting the respective texts into audio.

  NOTE 4: Subtitles that are bitmap images are examples where the content of the displayed captions will not be programmatically determinable.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.2.1 Audio description playback

  Where ICT displays video with synchronized audio, it shall provide a mechanism to select and play available audio description to the default audio channel.

  Where video technologies do not have explicit and separate mechanisms for audio description, an ICT is deemed to satisfy this requirement if the ICT enables the user to select and play several audio tracks.

  NOTE 1: In such cases, the video content can include the audio description as one of the available audio tracks.

  NOTE 2: Audio descriptions in digital media sometimes include information to allow descriptions that are longer than the gaps between dialogue. Support in digital media players for this "extended audio description" feature is useful, especially for digital media that is viewed personally.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.2.2 Audio description synchronization

  Where ICT has a mechanism to play audio description, it shall preserve the synchronization between the audio/visual content and the corresponding audio description.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.2.3 Preservation of audio description

  Where ICT transmits, converts, or records video with synchronized audio, it shall preserve audio description data such that it can be played in a manner consistent with clauses 7.2.1 and 7.2.2.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]

• 7.3 User controls for captions and audio description

  Where ICT primarily displays materials containing video with associated audio content, user controls to activate subtitling and audio description shall be provided to the user at the same level of interaction (i.e. the number of steps to complete the task) as the primary media controls.

  NOTE 1: Primary media controls are the set of controls that the user most commonly uses to control media.

  NOTE 2: Products that have a general hardware volume control, such as a telephone, or a laptop which can be configured to display video through software but which is not its primary purpose, would not need dedicated hardware controls for captions and descriptions; however software controls, or hardware controls mapped through software, would need to be at the same level of interaction.

  NOTE 3: It is best practice for ICT to include additional controls enabling the user to select whether captions and audio description are turned on or off by default.

  © ETSI 2021. All rights reserved

  Læs klausulen i EN 301 549 version 3.2.1 [engelsk]