FFmpeg cannot load files with non-latin characters by DirectShowSource2 of AviSynth+

[syehoonkim]

Summary of the bug:
How to reproduce:

% ffmpeg -i input.avs ... output
ffmpeg version N-115575-g4e120fbbbd-ffmpeg-windows-build-helpers Copyright (c) 2000-2024 the FFmpeg developers
  built with gcc 10.2.0 (GCC)
  configuration: --pkg-config=pkg-config --pkg-config-flags=--static --extra-version=ffmpeg-windows-build-helpers --enable-version3 --disable-debug --disable-w32threads --arch=x86_64 --target-os=mingw32 --cross-prefix=/home/syehoon/repos/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-x86_64/bin/x86_64-w64-mingw32- --enable-libcaca --enable-gray --enable-libtesseract --enable-fontconfig --enable-gmp --enable-libass --enable-libbluray --enable-libbs2b --enable-libflite --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libvorbis --enable-libwebp --enable-libzimg --enable-libzvbi --enable-libmysofa --enable-libopenjpeg --enable-libopenh264 --enable-libvmaf --enable-libsrt --enable-libxml2 --enable-opengl --enable-libdav1d --enable-gnutls --enable-libsvtav1 --enable-libvpx --enable-libaom --enable-nvenc --enable-nvdec --extra-libs=-lz --extra-libs=-lpng --extra-libs=-lm --extra-libs=-lfreetype --extra-libs=-lshlwapi --extra-libs=-lmpg123 --extra-libs=-lpthread --extra-cflags=-DLIBTWOLAME_STATIC --extra-cflags=-DMODPLUG_STATIC --extra-cflags=-DCACA_STATIC --enable-amf --enable-libmfx --enable-libaribcaption --enable-gpl --enable-frei0r --enable-librubberband --enable-libvidstab --enable-libx264 --enable-libx265 --enable-avisynth --enable-libaribb24 --enable-libxvid --enable-libdavs2 --enable-libxavs2 --enable-libxavs --extra-cflags='-mtune=generic' --extra-cflags=-O3 --enable-static --disable-shared --prefix=/home/syehoon/repos/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-x86_64/x86_64-w64-mingw32 --enable-nonfree --enable-libfdk-aac --enable-decklink
  libavutil      59. 21.100 / 59. 21.100
  libavcodec     61.  6.100 / 61.  6.100
  libavformat    61.  3.104 / 61.  3.104
  libavdevice    61.  2.100 / 61.  2.100
  libavfilter    10.  2.102 / 10.  2.102
  libswscale      8.  2.100 /  8.  2.100
  libswresample   5.  2.100 /  5.  2.100
  libpostproc    58.  2.100 / 58.  2.100
[avisynth @ 000002488fa24ac0] DSS2: Can't open "D:/sample_video/진신우부장님/DJI_0077.MOV"

Add Source: (80004005) �d������ �7�Դϴ�

(frameserver.avs, line 2)
[in#0 @ 000002488fa246c0] Error opening input: Unknown error occurred
Error opening input file frameserver.avs.
Error opening input files: Unknown error occurred

The input.avs loads the file by the command

DSS2("D:/sample_video/진신우부장님/DJI_0077.MOV")

If I move the file to the directory which doesn't include non-latin characters, FFmpeg works fine.
With DirectShowSource() function, there is no problem.
I suspect that FFmpeg has some problem on dealing with unicode in processing AviSynth+'s DSS2() function.