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var videojsAss = require("videojs-ass")

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videojs-ass v0.8.0

ASS/SSA subtitle overlay for videojs


Add Advanced SubStation Alpha (ASS) subtitles support to videojs using the libjass library.

Check out the demo here


For plugin that supports videojs v5.x install using either:

  • bower install videojs-ass


  • npm install videojs-ass

For videojs v4:

Just specify version to be within:

"videojs-ass": ">=0.3.0 < 0.5.0"

for bower or npm whichever you prefer using.


Initialize the ass plugin with the src field like the following:

videojs('player_id', {
  plugins: {
    ass: {
      src: 'subs/subtitles.ass'
src-1.ass / .ssa source.
label-2subtitle track label that shows up in the subtitles picker
delay03delay subtitle rendering by the specified value in seconds
rate1subtitle update speed relative to video playback rate
enableSvgtruesee here regarding SVG filter
fontMap-see here regarding using custom web fonts
fontMapById-alternate to above, takes id and runs this
videoWidth-4metadata to assist in determining the optimal (cont below)
videoHeight-4(cont) subtitle letterboxing ratio


  1. This property is required!
  2. Has fallback values but you should provide a better label.
  3. Value can be negative
  4. Generally, you should set these values when using external videojs providers as they might not expose the video dimensions to the player.


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