Special characters are not supported if the metadata is loaded from a .mkv file.

[Former user]

Special characters like é, á, ő, ű, í, ... do not appear correctly in titles.

[Petr Nejedly]

Could you post the result of

 ffmpeg -i <file> 

and confirm what is your OS and locale?

‌

[Suspicious Men]

Sorry for the late reply, but I haven’t visited the website in over a year. I only checked for a few weeks to see if I got any feedback.

My OS and locale: Windows 10 64-bit; Hungarian (Hungary)

I made a test with the following results:

ffmpeg version 2021-09-11-git-3e127b595a-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 10.3.0 (Rev5, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      57.  5.100 / 57.  5.100
  libavcodec     59.  7.103 / 59.  7.103
  libavformat    59.  5.100 / 59.  5.100
  libavdevice    59.  0.101 / 59.  0.101
  libavfilter     8.  9.100 /  8.  9.100
  libswscale      6.  1.100 /  6.  1.100
  libswresample   4.  0.100 /  4.  0.100
  libpostproc    56.  0.100 / 56.  0.100
Input #0, matroska,webm, from 'test.mkv':
  Metadata:
    title           : árvíztűrő tükörfúrógép - ÁRVÍZTŰRŐ TÜKÖRFÚRÓGÉP
    encoder         : libebml v1.4.2 + libmatroska v1.6.4
    creation_time   : 2021-09-13T17:49:06.000000Z
  Duration: 00:00:33.07, start: 0.000000, bitrate: 983 kb/s
  Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(tv, smpte170m/smpte170m/bt709, progressive), 640x360, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 1k tbn (default)
    Metadata:
      BPS             : 866659
      DURATION        : 00:00:32.520000000
      NUMBER_OF_FRAMES: 813
      NUMBER_OF_BYTES : 3522970
      _STATISTICS_WRITING_APP: mkvmerge v61.0.0 ('So') 64-bit
      _STATISTICS_WRITING_DATE_UTC: 2021-09-13 17:49:06
      _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
  Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp (default)
    Metadata:
      BPS             : 127540
      DURATION        : 00:00:33.065000000
      NUMBER_OF_FRAMES: 1424
      NUMBER_OF_BYTES : 527140
      _STATISTICS_WRITING_APP: mkvmerge v61.0.0 ('So') 64-bit
      _STATISTICS_WRITING_DATE_UTC: 2021-09-13 17:49:06
      _STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES

In this result, the title I entered (“árvíztűrő tükörfúrógép - ÁRVÍZTŰRŐ TÜKÖRFÚRÓGÉP“) will appear correctly, but it will appear in the media list as follows:

‌

Sorry for my imperfect English, but I hope I was still able to help detect the problem!