Filter ahistogram with slide=scroll crashes

[John Warburton]

Summary of the bug:

The ahistogram filter with slide=scroll crashes. Without specifying slide (i.e. replace mode) the filter works perfectly.

This problem started at some point since mid-February 2022.

Platform is mingw-w64, compiled with GCC 12.0.1

Happy to test any patches you might like me to try.

How to reproduce:

% ffmpeg -i http://warblefly.sytes.net:8001/audio-hifi.aac -filter_complex "[0:0]ahistogram=slide=scroll" output.mp4

FFmpeg is version N-106318-g710e51677a built on March 18 2022.

GDB gives this trace:

warning: Critical error detected c0000374

Thread 1 received signal SIGTRAP, Trace/breakpoint trap.
0x00007ff85749ca63 in ntdll!RtlIsZeroMemory () from C:\WINDOWS\SYSTEM32\ntdll.dll
(gdb) bt
#0  0x00007ff85749ca63 in ntdll!RtlIsZeroMemory () from C:\WINDOWS\SYSTEM32\ntdll.dll
#1  0x00007ff8574a5a9a in ntdll!.misaligned_access () from C:\WINDOWS\SYSTEM32\ntdll.dll
#2  0x00007ff8574a5d7a in ntdll!.misaligned_access () from C:\WINDOWS\SYSTEM32\ntdll.dll
#3  0x00007ff8574b0305 in ntdll!.misaligned_access () from C:\WINDOWS\SYSTEM32\ntdll.dll
#4  0x00007ff8573c3fdf in ntdll!RtlAllocateHeap () from C:\WINDOWS\SYSTEM32\ntdll.dll
#5  0x00007ff8573c0969 in ntdll!RtlAllocateHeap () from C:\WINDOWS\SYSTEM32\ntdll.dll
#6  0x00007ff857494b92 in ntdll!RtlRegisterSecureMemoryCacheCallback () from C:\WINDOWS\SYSTEM32\ntdll.dll
#7  0x00007ff85744ec36 in ntdll!RtlNotifyFeatureUsage () from C:\WINDOWS\SYSTEM32\ntdll.dll
#8  0x00007ff8573c0969 in ntdll!RtlAllocateHeap () from C:\WINDOWS\SYSTEM32\ntdll.dll
#9  0x00007ff8564ecb80 in msvcrt!malloc () from C:\WINDOWS\System32\msvcrt.dll
#10 0x00007ff8564ec22c in msvcrt!_aligned_offset_malloc () from C:\WINDOWS\System32\msvcrt.dll
#11 0x00007fffb2598542 in avutil-57!av_malloc () from C:\Program Files\ffmpeg\bin\avutil-57.dll
#12 0x00007fffb2578673 in avutil-57!av_frame_clone () from C:\Program Files\ffmpeg\bin\avutil-57.dll
#13 0x00007fffb27e84ab in avfilter_get_by_name () from C:\Program Files\ffmpeg\bin\avfilter-8.dll
#14 0x00007fffb28023fa in avfilter_pad_get_type () from C:\Program Files\ffmpeg\bin\avfilter-8.dll
#15 0x00007fffb2807360 in avfilter-8!av_buffersrc_add_frame_flags () from C:\Program Files\ffmpeg\bin\avfilter-8.dll
#16 0x00007ff7e1df45ad in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

[Elon Musk]

Fixed in 7ae2ded0d12bb36a82ee928c3a543a00aee4b466

[John Warburton]

Thanks very much for the quick fix, and for stating the reason in the comment. This filter is something I use regularly in demonstrations to students while illustrating use of FFmpeg so it's great to have it back, in this mode. JW