Dear Maintainer,

The latest version of the svt-av1 encoder library triggers a
segmentation fault in ffmpeg and SvtAv1EncApp. This is the problematic
version:

libsvtav1enc4_4.2.0+dfsg-1_amd64.deb

The segmentation fault occurs when I use ffmpeg with the option "-c:v
libsvtav1" but also occurs when I use SvtAv1EncApp directly. So I
believe this is not just an ffmpeg bug.

With the assistance of Cat-GPT-6, I produced a gdb trace of the
segmentation fault as it occurs with ffmpeg. The error output is
appended to the end of this bug report.

$ gdb -q -batch -ex 'set pagination off' -ex run -ex 'bt 8' --args
ffmpeg -hide_banner -loglevel error -nostdin -y -i test.mp4 -c:v
libsvtav1 /tmp/svt42-test.webm > /tmp/svt42-gdb.txt 2>&1; tail -n 25
/tmp/svt42-gdb.txt

The segmenatation fault doesn't happen when I run ffmpeg with the
previous version of libsvtav1enc4, namely:

libsvtav1enc4_4.1.0+dfsg-1_amd64.deb

Control: forwarded -1 https://gitlab.com/AOMediaCodec/SVT-AV1/-/work_items/2382

This is https://gitlab.com/AOMediaCodec/SVT-AV1/-/work_items/2382.

Cheers

We believe that the bug you reported is fixed in the latest version of
svt-av1, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1151366@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Sebastian Ramacher <sramacher@debian.org> (supplier of updated svt-av1 package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Tue, 20 Oct 2026 21:29:38 +0200
Source: svt-av1
Architecture: source
Version: 4.2.0+dfsg-2
Distribution: unstable
Urgency: medium
Maintainer: Debian Multimedia Maintainers <debian-multimedia@lists.debian.org>
Changed-By: Sebastian Ramacher <sramacher@debian.org>
Closes: 1151366
Changes:
 svt-av1 (4.2.0+dfsg-2) unstable; urgency=medium
 .
   * debian/patches: Apply upstream patch to fix unaligned load (Closes:
     #1151366)
Checksums-Sha1:
 cc4d617f591787ab18babdfd753230a5974e22ee 1645 svt-av1_4.2.0+dfsg-2.dsc
 6b5b8deb8b610d59fec2a3c97539c1f3f5e80b0b 8692 svt-av1_4.2.0+dfsg-2.debian.tar.xz
 03705d328ed00a132a488c621daade4e81d76b15 7354 svt-av1_4.2.0+dfsg-2_amd64.buildinfo
Checksums-Sha256:
 4b88af4e1efbcb348bc15b4870d0b6908407abb989b6f44ec74f621731b4e243 1645 svt-av1_4.2.0+dfsg-2.dsc
 6a04d665165f613429c72ffae0e37772fb7615c68e5cd642945a67680effb364 8692 svt-av1_4.2.0+dfsg-2.debian.tar.xz
 1fd7dcf8134f90903e7dd5a7faee00c5113c71c5f8a76441656bd70f67e4688f 7354 svt-av1_4.2.0+dfsg-2_amd64.buildinfo
Files:
 733cb04cc29bb5c4b11f57c0c3b15eac 1645 video optional svt-av1_4.2.0+dfsg-2.dsc
 104bcbf5a7287c6af011147fcd975926 8692 video optional svt-av1_4.2.0+dfsg-2.debian.tar.xz
 b5b50349eac02deb837c3118b26132d5 7354 video optional svt-av1_4.2.0+dfsg-2_amd64.buildinfo
-----BEGIN PGP SIGNATURE-----

wr0EARYKAG8FgmrXwekJECGTazZgD82JRxQAAAAAAB4AIHNhbHRAbm90YXRpb25z
LnNlcXVvaWEtcGdwLm9yZ1vjcrQxXUX9HNd1IeAtYZAZX8XUtNUR5jp41EWgV5fc
FiEEQmJ+hB2ZZ9qD4fqQIZNrNmAPzYkAAOyVAQD8mmptULFp6Sz1PNhbzY5Z4Xak
V1t7/SSEPe0M92jakAD+JqJjSm3z6lMYAEMvHERktopXn4I5KOIIwWp/77tTNgk=
=8t68
-----END PGP SIGNATURE-----