Issues

• Crash: Floating-point to integer conversion overflow in ass_render_event() on extreme override-tag values (CWE-681) -> UBSAN SIGILL

  bug
  libass/libass#948 · Filter by author 1820893135-pixel opened on Aug 16, 2026

• Crash: Signed integer subtraction overflow in ass_outline_construct (and float-to-int overflow in ass_render_event) on extreme numeric subtitle input -> UBSAN SIGILL

  bug
  libass/libass#947 · Filter by author 1820893135-pixel opened on Aug 16, 2026

• Unbounded memory use when tokenizing ASS drawing commands

  libass/libass#945 · Filter by author acts-1631 opened on Jul 21, 2026
  2

• Rendering: Mispositioned combining marks when base and mark glyphs use different fonts

  compatibilityshaper
  libass/libass#932 · Filter by author moi15moi opened on Jun 6, 2026

• Crash: UBSan: signed integer overflow in ass_render.c when processing \p vector drawing commands

  bug
  libass/libass#931 · Filter by author wolfvoid opened on Jun 1, 2026

• Libass loads WOFF/WOFF2 script-embedded fonts, while VSFilter doesn't

  compatibility
  libass/libass#923 · Filter by author Jukizuka opened on May 2, 2026
  3

• Font gets reduced character spacing with GDI/VSFilter faux bold

  compatibilityfonts
  libass/libass#905 · Filter by author astiob opened on Oct 24, 2025
  2

• Rendering: Incompatibility with non-ASCII numerals in tag parameters (e.g., Burmese, Arabic, Fullwidth digits)

  compatibilityparser
  libass/libass#893 · Filter by author amanosatosi opened on Jul 6, 2025
  4

• Adding animated transform to \pos

  question
  libass/libass#886 · Filter by author jeybee opened on Jun 9, 2025
  5

• Rendering: Aliased Shape Rendering

  compatibility
  libass/libass#881 · Filter by author witchymary opened on May 9, 2025
  3

• Merely splitting up a long moving line of text speeds up rendering

  performance
  libass/libass#844 · Filter by author astiob opened on Oct 28, 2024
  4

• [RFC/Discussion] Text to shape / Text metrics API

  api
  libass/libass#825 · Filter by author arch1t3cht opened on Sep 12, 2024
  6

• Artefacts near border corners with specific resolutions

  quality
  libass/libass#802 · Filter by author op200 opened on Jul 10, 2024
  2

• [DirectWrite] libass doesn't always find a fallback font

  fontswindows
  libass/libass#791 · Filter by author moi15moi opened on Jun 19, 2024
  3

• Discuss: -ffast-math and other math optimization flags

  buildperformance
  libass/libass#782 · Filter by author rcombs opened on Jun 4, 2024
  14

• Overhaul fontselect: individual, cached, full-detail queries

  enhancementfonts
  libass/libass#771 · Filter by author astiob opened on May 23, 2024
  6

• Separate muxed/memory fonts from system fonts

  fonts
  libass/libass#761 · Filter by author rcombs opened on May 15, 2024

• Rendering: Different case for a non-ASCII character doesn't find the font

  compatibilityfonts
  libass/libass#752 · Filter by author moi15moi opened on Apr 22, 2024

• Rendering: natural line break punctuation position in RTL languages

  compatibility
  libass/libass#741 · Filter by author TsUNaMyWaVe opened on Mar 19, 2024
  2

• Inline fallback fonts should be sized to main font’s EM height, not line height

  compatibilityfonts
  libass/libass#739 · Filter by author astiob opened on Mar 12, 2024

• Rendering: Wrong font used for mpv OSD on Fedora 39+

  fonts
  libass/libass#737 · Filter by author luk1337 opened on Mar 9, 2024
  2

• Rendering: performance issue while rendering running rainbow animated subtitles

  performance
  libass/libass#736 · Filter by author NBruderman opened on Mar 8, 2024
  4

• \ko fails to remove outline from shadow

  compatibility
  libass/libass#733 · Filter by author arch1t3cht opened on Feb 2, 2024
  3

• Investigate unexpected vsfilter behavior with \h on certain font

  compatibilityfonts
  libass/libass#706 · Filter by author rcombs opened on Sep 10, 2023
  15

• Request: GPU rendering backend

  request
  libass/libass#704 · Filter by author ghost opened on Aug 16, 2023
  1