Overview: Fonts and typesetting

Fonts and typesetting translate subtitle characters and styling instructions into positioned, shaped visual text.

A selected font contributes glyph appearance and coverage. Fallback or attached fonts affect which resource is used; ASS typesetting and karaoke timing add placement, transforms and timed presentation behavior. The result depends on the renderer applying those instructions with the available font resources.

• Subtitle font fallback
  Subtitle font fallback selects usable faces when a requested font or required glyph is unavailable, which can change both shape and layout metrics.

• Subtitle font attachments
  Subtitle font attachments bundle font resources with media so a supporting renderer can use the intended faces for styled text.

• ASS typesetting
  ASS typesetting coordinates font layout, anchors, layers, transforms, clipping and event timing to integrate subtitle text with a scene.

• Karaoke subtitle timing
  Karaoke subtitle timing controls changes within a displayed line, using syllable durations and highlight behavior relative to its event interval.