libass/libass
libass is a portable subtitle renderer for the ASS/SSA (Advanced Substation Alpha/Substation Alpha) subtitle format. observed · 2026-08-28
Health v2 · maintenance only
85/100
- Activity 99
- Release rhythm 58
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: 381
- age_days: 4786
- days_rel: 70
- days_push: 11
- n_releases_24m: 2
Adoption not part of the score
1161 stars · 247 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
libass is a portable C library that renders ASS/SSA (Advanced Substation Alpha) subtitles, mostly compatible with VSFilter. It is widely used by video players such as VLC, mpv, and ffmpeg to display styled subtitles.
Use cases
- render ASS/SSA subtitles in a video player
- burn styled subtitles into video with ffmpeg
- add karaoke and animated subtitle effects to playback
- portably display advanced subtitle formatting across platforms
- replace VSFilter in a DirectShow or VapourSynth pipeline
When to choose
- you need accurate, VSFilter-compatible ASS/SSA subtitle rendering
- you are building or extending a media player or transcoding tool
- you need a portable C library with cross-platform builds
When to avoid
- you only need simple SRT subtitle rendering without styling
- you want a ready-made player rather than a rendering library
Facets
library · maturity stable
graphics image-processing parser media cross-platform windows cross-platform cpp subtitles ass ssa subtitle-rendering vsfilter-compatible c-library video linux macos
1 source
- readme: https://github.com/libass/libass · fetched 2026-08-28 · 88a5b96874ac
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| libass/libass | main | 85 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem