Trim / Clip

Play only a specific time window of a video — set a start and/or end in seconds. The player loops seamlessly within the clip. Works in both live streaming and preExtract modes.

Live preview

no trim — full loop

press run →

Plays the full video, looping from start.

{ /* no trim */ }

trim: 2s → 5s loop

press run →

Loops only the 2s–5s window, seamlessly.

{ trim: { start: 2, end: 5 } }

Usage

trim.ts

import { asciifyVideo } from 'asciify-engine';

// Loop seconds 2–8 only
const stop = await asciifyVideo('/clip.mp4', canvas, {
  trim: { start: 2, end: 8 },
});

// Start at 5s, loop to end of file
const stop = await asciifyVideo('/clip.mp4', canvas, {
  trim: { start: 5 },
});

// End at 10s from the beginning (no offset)
const stop = await asciifyVideo('/clip.mp4', canvas, {
  trim: { end: 10 },
});

With preExtract

In preExtract mode, only frames within the trim window are decoded — no wasted memory.

asciifyVideo('/clip.mp4', canvas, {
  preExtract: true,
  trim: { start: 2, end: 6 }, // only extracts 4 seconds worth of frames
});

Tip

Combine with chromaKey to loop a trimmed green screen clip with full transparency:

asciifyVideo('/greenscreen.mp4', canvas, {
  trim: { start: 1, end: 7 },
  options: {
    chromaKey: true,
    colorMode: 'fullcolor',
  },
});