Subforge

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PGS ​

Presentation Graphic Stream (PGS) is a bitmap subtitle format used by Blu-ray.

Timing ​

  • PTS in a 90 kHz clock

Images ​

  • Subforge exposes bitmap data on event.image and PGS metadata on event.pgs.
  • segments can be empty for image-based events.

Parsing ​

ts
import { parsePGS } from 'subforge/pgs'
import { unwrap } from 'subforge/core'

const data = new Uint8Array(await fetch('/subs.pgs').then(r => r.arrayBuffer()))
const doc = unwrap(parsePGS(data))

Serialization ​

ts
import { toPGS } from 'subforge/pgs'

const out = toPGS(doc) // Uint8Array