Loading more than 2 files in the signature filter consumes a lot of memory

[nicol]

Summary of the bug:
When the command is executed, memory consumption increases linearly and in about 600 seconds video, the memory usage of the 64 GB Windows is nearly 100%.
When checked in Task Manager, the ffmpeg process in the Process tab does not have a large memory consumption, but the memory consumption in the Performance tab is 100%.

How to reproduce:

% ffmpeg -f lavfi -i testsrc2=s=1920x1080:r=30000/1001:d=600 -filter_complex split,signature=nb_inputs=2:detectmode=full:format=xml:filename=test%d.xml -f null -
ffmpeg version N-119864-gf531c91170-20250610 : btbn
built on ... Windows 11

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.