[FFmpeg-trac] #8237(undetermined:new): Division by zero at libavfilter/af_adeclick.c

[FFmpeg]

#8237: Division by zero at libavfilter/af_adeclick.c
-------------------------------------+-------------------------------------
             Reporter:  Suhwan       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:  ubsan        |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 There are 2 Division by zero at libavfilter/af_adeclick.c:684,228
 {{{
 Breakpoint 1, uninit (ctx=0x611000000900) at libavfilter/af_adeclick.c:684
 684                s->nb_samples, 100. * s->detected_errors /
 s->nb_samples);
 (gdb) print s->nb_samples
 $1 = 0
 (gdb) bt
 #0  uninit (ctx=0x611000000900) at libavfilter/af_adeclick.c:684
 #1  0x000000000110cde1 in avfilter_free (filter=0x611000000900) at
 libavfilter/avfilter.c:771
 #2  0x0000000001174600 in avfilter_graph_free (graph=0x7fffffffdb20) at
 libavfilter/avfiltergraph.c:126
 #3  0x00000000006e02d0 in init_complex_filtergraph (fg=0x60a000000040) at
 fftools/ffmpeg_filter.c:377
 #4  0x00000000005173c9 in init_complex_filters () at
 fftools/ffmpeg_opt.c:2102
 #5  ffmpeg_parse_options (argc=<optimized out>, argv=<optimized out>) at
 fftools/ffmpeg_opt.c:3324
 #6  0x000000000081bc75 in main (argc=23, argv=0x7fffffffe138) at
 fftools/ffmpeg.c:4872
 (gdb) c
 Continuing.

 libavfilter/af_adeclick.c:684:53: runtime error: division by zero
 SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
 libavfilter/af_adeclick.c:684:53 in
 libavfilter/af_adeclick.c:228:25: runtime error: division by zero
 SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
 libavfilter/af_adeclick.c:228:25 in
 }}}
 How to reproduce:
 {{{
 % ffmpeg_g -y -r 49 -i $PoC -filter_complex adeclick -loglevel 0 -c:s:7
 h264_v4l2m2m -disposition:s:3 apng -vframes 35 -ab 267k -ac 0 -strict 1
 tmp.ast

 ffmpeg version N-95291-g5345965b3f Copyright (c) 2000-2019 the FFmpeg
 developers
   built with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
   configuration: --cc=clang --cxx=clang++ --ld=clang --enable-debug
 --toolchain=clang-usan
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8237>
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