Package: libsvtav1enc4
Version: 4.2.0+dfsg-1
Severity: important
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
-- System Information:
Debian Release: forky/sid
APT prefers testing
APT policy: (900, 'testing'), (90, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386, arm64
Kernel: Linux 7.1.7+deb14-amd64 (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_CPU_OUT_OF_SPEC
Locale: LANG=en_SG.UTF-8, LC_CTYPE=en_SG.UTF-8 (charmap=UTF-8), LANGUAGE
not set
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled
Versions of packages libsvtav1enc4 depends on:
ii libc6 2.43-7
-- BEGIN GDB OUTPUT
[Thread debugging using libthread_db enabled]
Using host libthread_db library
"/usr/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffea2a96c0 (LWP 14049) (id 2)]
[New Thread 0x7fffe9aa86c0 (LWP 14050) (id 3)]
[New Thread 0x7fffe92a76c0 (LWP 14051) (id 4)]
[New Thread 0x7fffe8aa66c0 (LWP 14052) (id 5)]
[New Thread 0x7fffe82a56c0 (LWP 14053) (id 6)]
[New Thread 0x7fffe7aa46c0 (LWP 14054) (id 7)]
[New Thread 0x7fffe72a36c0 (LWP 14055) (id 8)]
[New Thread 0x7fffe6aa26c0 (LWP 14056) (id 9)]
[New Thread 0x7fffe62a16c0 (LWP 14057) (id 10)]
[New Thread 0x7fffe54a36c0 (LWP 14058) (id 11)]
[New Thread 0x7fffe4aa36c0 (LWP 14059) (id 12)]
[New Thread 0x7fffc7fff6c0 (LWP 14060) (id 13)]
[New Thread 0x7fffc77fe6c0 (LWP 14061) (id 14)]
Svt[info]: -------------------------------------------
Svt[info]: SVT [version]: SVT-AV1 Encoder Lib v4.2.0
Svt[info]: SVT [build] : GCC 16.2.0 64 bit
Svt[info]: -------------------------------------------
Svt[info]: Level of Parallelism: 3
Svt[info]: Number of PPCS 42
Svt[info]: [asm level on system : up to sse4_1]
Svt[info]: [asm level selected : up to sse4_1]
Svt[info]: -------------------------------------------
Svt[info]: SVT [config]: main profile tier (auto) level (auto)
Svt[info]: SVT [config]: width / height / fps numerator / fps
denominator : 1920 / 1080 / 43 / 3
Svt[info]: SVT [config]: bit-depth / color format
: 8 / YUV420
Svt[info]: SVT [config]: preset / tune / pred struct : 8 / PSNR /
random access
Svt[info]: SVT [config]: gop size / mini-gop size / key-frame type :
81 / 16 / key frame
Svt[info]: SVT [config]: BRC mode / rate factor
: CRF / 35.00
Svt[info]: SVT [config]: AQ mode / Variance Boost
: 2 / 0
Svt[info]: SVT [config]: sharpness / luminance-based QP bias
: 0 / 0
Svt[info]: SVT [config]: QP scale compress strength
: 0
Svt[info]: -------------------------------------------
[New Thread 0x7fffb81f66c0 (LWP 14062) (id 15)]
[New Thread 0x7fffac1966c0 (LWP 14063) (id 16)]
[New Thread 0x7fffa41556c0 (LWP 14064) (id 17)]
[New Thread 0x7fff9c4796c0 (LWP 14065) (id 18)]
[New Thread 0x7fff9c3786c0 (LWP 14066) (id 19)]
[New Thread 0x7fff9c2776c0 (LWP 14067) (id 20)]
[New Thread 0x7fff9c1766c0 (LWP 14068) (id 21)]
[New Thread 0x7fff7ffff6c0 (LWP 14069) (id 22)]
[New Thread 0x7fff7fefe6c0 (LWP 14070) (id 23)]
[New Thread 0x7fff7fdfd6c0 (LWP 14071) (id 24)]
[New Thread 0x7fff7fcfc6c0 (LWP 14072) (id 25)]
[New Thread 0x7fff7fbfb6c0 (LWP 14073) (id 26)]
[New Thread 0x7fff7fafa6c0 (LWP 14074) (id 27)]
[New Thread 0x7fff7f9f96c0 (LWP 14075) (id 28)]
[New Thread 0x7fff7f8f86c0 (LWP 14076) (id 29)]
[New Thread 0x7fff7f7f76c0 (LWP 14077) (id 30)]
[New Thread 0x7fff7f6f66c0 (LWP 14078) (id 31)]
[New Thread 0x7fff7f5f56c0 (LWP 14079) (id 32)]
[New Thread 0x7fff7f4f46c0 (LWP 14080) (id 33)]
[New Thread 0x7fff7f3f36c0 (LWP 14081) (id 34)]
[New Thread 0x7fff7f2f26c0 (LWP 14082) (id 35)]
[New Thread 0x7fff7f1f16c0 (LWP 14083) (id 36)]
[New Thread 0x7fff7f0f06c0 (LWP 14084) (id 37)]
[New Thread 0x7fff7efef6c0 (LWP 14085) (id 38)]
[New Thread 0x7fff7eeee6c0 (LWP 14086) (id 39)]
[New Thread 0x7fff7eded6c0 (LWP 14087) (id 40)]
[New Thread 0x7fff7ecec6c0 (LWP 14088) (id 41)]
[New Thread 0x7fff7ebeb6c0 (LWP 14090) (id 42)]
[New Thread 0x7fff7eaea6c0 (LWP 14091) (id 43)]
[New Thread 0x7fff7e9e96c0 (LWP 14092) (id 44)]
[New Thread 0x7fff7e8e86c0 (LWP 14093) (id 45)]
[New Thread 0x7fff7e7e76c0 (LWP 14094) (id 46)]
[New Thread 0x7fff7e6e66c0 (LWP 14095) (id 47)]
[New Thread 0x7fff7e5e56c0 (LWP 14096) (id 48)]
[New Thread 0x7fff7e4e46c0 (LWP 14097) (id 49)]
[New Thread 0x7fff7e3e36c0 (LWP 14098) (id 50)]
[New Thread 0x7fff7e2e26c0 (LWP 14099) (id 51)]
[New Thread 0x7fff7e1e16c0 (LWP 14100) (id 52)]
[New Thread 0x7fff7e0e06c0 (LWP 14101) (id 53)]
[New Thread 0x7fff7dfdf6c0 (LWP 14102) (id 54)]
[New Thread 0x7fff7dede6c0 (LWP 14103) (id 55)]
[New Thread 0x7fff7dddd6c0 (LWP 14104) (id 56)]
[New Thread 0x7fff7dcdc6c0 (LWP 14105) (id 57)]
[New Thread 0x7fff7dbdb6c0 (LWP 14106) (id 58)]
[New Thread 0x7fff7dada6c0 (LWP 14107) (id 59)]
[New Thread 0x7fff7d9d96c0 (LWP 14108) (id 60)]
[New Thread 0x7fff7d8d86c0 (LWP 14109) (id 61)]
[New Thread 0x7fff7d7d76c0 (LWP 14110) (id 62)]
[New Thread 0x7fff7d6d66c0 (LWP 14111) (id 63)]
[New Thread 0x7fff7d5d56c0 (LWP 14112) (id 64)]
[New Thread 0x7fff7d4d46c0 (LWP 14113) (id 65)]
[New Thread 0x7fff7d3d36c0 (LWP 14114) (id 66)]
[New Thread 0x7fff7d2d26c0 (LWP 14115) (id 67)]
[New Thread 0x7fff7d1d16c0 (LWP 14116) (id 68)]
[New Thread 0x7fff7d0d06c0 (LWP 14117) (id 69)]
[New Thread 0x7fff7cfcf6c0 (LWP 14118) (id 70)]
[New Thread 0x7fff7cece6c0 (LWP 14119) (id 71)]
[New Thread 0x7fff7cdcd6c0 (LWP 14120) (id 72)]
[New Thread 0x7fff7cccc6c0 (LWP 14121) (id 73)]
[New Thread 0x7fff7cbcb6c0 (LWP 14122) (id 74)]
[New Thread 0x7fff7caca6c0 (LWP 14123) (id 75)]
[New Thread 0x7fff7c9c96c0 (LWP 14124) (id 76)]
[Thread 0x7fffe62a16c0 (LWP 14057) (id 10) exited]
Thread 56 "svt-md1" received signal SIGSEGV, Segmentation fault.
[Switching to thread 56 (Thread 0x7fff7dddd6c0 (LWP 14104))]
0x00007fffee42fed5 in svt_aom_sub_pixel_variance16xh_ssse3 () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#0 0x00007fffee42fed5 in svt_aom_sub_pixel_variance16xh_ssse3 () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#1 0x00007fffee1070fa in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#2 0x00007fffedfe50b0 in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#3 0x00007fffee000ce4 in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#4 0x00007fffedffd2de in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#5 0x00007fffedeb64cb in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#6 0x00007fffedeb9479 in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
#7 0x00007fffee05c4ad in ?? () from
/usr/lib/x86_64-linux-gnu/libSvtAv1Enc.so.4
-- END GDB OUTPUT
