#9117 closed defect (fixed)
libx265 segfault error while encoding
Reported by: | Arno BERND | Owned by: | |
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Priority: | normal | Component: | undetermined |
Version: | unspecified | Keywords: | libx265 |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug: Unpredictable segault errors when trying to encode multiple videos with libx265.
How to reproduce:
Just use about 6 parallel running commands % ffmpeg -loglevel quiet -y -i <file_mp4> -vcodec libx265 -x265-params log-level=-1 <file2_mp4> ffmpeg version 4.3.1 built on SUSE Linux with gcc 10
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.
Attachments (1)
Change History (5)
by , 3 years ago
Attachment: | segfaults.txt added |
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comment:1 by , 3 years ago
Component: | ffmpeg → undetermined |
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Keywords: | ffmpeg encoder removed |
Replying to babu59:
Unpredictable segault errors
This usually does not indicate a bug that can be fixed in software.
To make this a valid ticket, please test current FFmpeg git head and provide backtrace, disassembly and register dump as explained on https://ffmpeg.org/bugreports.html
comment:2 by , 5 months ago
Resolution: | → fixed |
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Status: | new → closed |
I discovered, that this error seems to be a run into architecture limitations, when I use libx265 without pool and frame limitations. I cannot really ensure this because I am still not able to reproduce the error consistently.
Since I limited "pools" and "frames" I am able to run multiple conversions in parallel to be able to use 100% CPU on a modern processor with 16/32 cores/threads.
I assume it's a stack pointer overflow.
Problem is now solved for me!
comment:3 by , 5 months ago
To complete my infomation:
Command which works without errors is now
ffmpeg -loglevel quiet -y -i <file_mp4> -vcodec libx265 -x265-params log-level=-1:frame-threads=1:pools=6 <file2>
Running 10 ffmpeg-tasks in parallel with full-HD (1920x1080) uses about 99% CPU on AMD Ryzen 9 5950x.
comment:4 by , 5 months ago
Summary: | libx265 sgefault error while encoding → libx265 segfault error while encoding |
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output from dmesg when error occurs