Subtitles & SDH

RTL Deutschland’s long-term goal is to provide accessible content across its entire offering. High-quality technical implementation of accessible content reflects RTL’s quality standards. This page provides important information on the creation and delivery of subtitles in general, and SDH subtitles in particular.

 

Specifications and Guidelines for Subtitle Files

The following information provides an overview of the specifications and formatting requirements for subtitle files to be delivered. It also includes information on the configuration of subtitle processing for RTL Deutschland’s channels.

File Format

  • Subtitle files must be delivered in EBU STL format.
  • In addition, a text file containing timecode information must be provided.
  • The frame rate must correspond to that of the source material, unless otherwise agreed.
  • The subtitle file must be timecode-identical to the video material provided by RTL.

Position in the Picture

  • RTL Technology defines 23 subtitle lines.
  • Subtitles must be positioned centrally at the bottom of the picture (line 20ff.).
  • If inserts are present at the bottom of the picture, subtitles must be positioned centrally at the top of the picture (line 1) for the entire duration of the inserts. This ensures that no inserts are obscured by the subtitles and avoids the subtitles switching between the top and bottom of the picture.
  • Text information displayed as inserts in the picture should not be repeated redundantly in the subtitles.
  • A subtitle may consist of a maximum of two lines. Each line may contain a maximum of 40 characters, including spaces.

Font Used for Broadcast

  • For all RTL Deutschland channels, the font, font size and color used for broadcast are fixed to Helvetica CE55 Roman in yellow.
  • Any differing information contained in the STL file will be overridden during broadcast.
  • The configuration supports the display of highlighted and italic text, as well as positioning (top/bottom/left/right).

Display Duration

  • The display duration depends on the number of characters per subtitle and should be at least 1.5 seconds.
  • The reading speed should not exceed 15 characters per second.
  • The minimum gap between two subtitles is generally four frames. For large amounts of text or dense dialogue, this gap may be reduced to one frame.

 

Subtitles for the Deaf and Hard of Hearing (SDH)

If available, the delivery of SDH subtitles is desirable:

  • In addition to spoken dialogue, SDH subtitles should include relevant background sounds and music (closed captions).
  • Subtitles must remain as close as possible to the spoken dialogue and be displayed in sync with the picture and audio, taking cuts into account.
  • Spelling must comply with the current German orthographic rules.