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WebVTT decoder

Register name used to load filter: vttdec
This filter may be automatically loaded during graph resolution.

This filter decodes WebVTT streams into a SVG scene graph of the compositor filter.
The scene graph creation is done through JavaScript.
The filter options are used to override the JS global variables of the WebVTT renderer.
In stand-alone rendering (no associated video), the filter will use:

  • Width and Height properties of input pid if any
  • otherwise, osize option of compositor if set
  • otherwise, txtw and txth


script (str, default: $GSHARE/scripts/webvtt-renderer.js): location of WebVTT SVG JS renderer
font (str, default: SANS, updatable): font
fontSize (flt, default: 20, updatable): font size
color (str, default: white, updatable): text color
lineSpacing (flt, default: 1.0, updatable): line spacing as scaling factor to font size
txtw (uint, default: 400): default width in standalone rendering
txth (uint, default: 200): default height in standalone rendering