Control: forwarded -1 https://gitlab.com/AOMediaCodec/SVT-AV1/-/work_items/2382
On 2026-10-20 14:39:32 +0800, Low Salt Popcorn wrote: > 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 This is https://gitlab.com/AOMediaCodec/SVT-AV1/-/work_items/2382. Cheers > /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 > -- Sebastian Ramacher
