# po5/thumbfast

High-performance on-the-fly thumbnailer script for mpv

Repository: https://github.com/po5/thumbfast
Canonical: https://ross.abutalabs.com/products/thumbfast
Language: Lua
License: MPL-2.0
License Family: copyleft
Topics: mpv, mpv-script, preview, thumbnails
Last push: 2026-08-12T15:02:41+00:00

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 35, longevity 100
- inputs: {"age_days": 1450, "days_push": 21, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1674, forks 51 (observed 2026-08-28T04:05:20.344520+00:00)

## What it is
A high-performance Lua script for the mpv media player that generates on-the-fly seekbar thumbnails without background CPU usage. It acts as a backend that UI scripts like uosc or ModernX call to display preview thumbnails when hovering over the timeline.

## Use cases
- show video preview thumbnails when hovering over the mpv seekbar
- add timeline thumbnail previews to a custom mpv UI script
- generate thumbnails on demand without background thumbnail generation hogging CPU
- preview YouTube and web videos in mpv while scrubbing the timeline
- use thumbnail previews with mpv frontends like mpv.net or ImPlay

## When to choose
- you use mpv and want seekbar thumbnail previews with no dependencies and minimal CPU overhead
- you maintain or use a custom mpv UI (uosc, ModernX, progressbar, etc.) and want to integrate thumbnail support
- you need thumbnails that respect applied video filters and mixed aspect ratio videos

## When to avoid
- you want a standalone thumbnail generator or a GUI that displays thumbnails on its own - this script requires a separate UI script to render them
- you do not use mpv or an mpv-based frontend
- you need pre-generated thumbnail galleries or background thumbnail caching

## Facets
- artifact type: plugin
- maturity: active
- function: video-processing, gui, developer-tools
- domain: media, desktop-applications, cross-platform
- platform: windows, lua
- tags: mpv-script, thumbnailer, video-preview, seekbar-thumbnails, media-player, linux, macos

## Member repositories
- po5/thumbfast (main) score 76

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:20.344520+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:42:33.136723+00:00, confidence not recorded.
  - readme: https://github.com/po5/thumbfast (fetched 2026-08-28T04:05:20.344520+00:00, sha bdac451cc174)
- Data as of 2026-08-30T08:39:29.467469+00:00.