Cannot render non-ASCII characters with ffmpeg's drawtext

Using the drawtext filter in ffmpeg I am unable to use anything but ASCII characters. This command creates a five second test video, as expected (nothing pretty): ffmpeg -f lavfi -i testsrc -to 5 -vf "drawtext=text='ＡＴ 05 ーポン 攢ð':fontcolor=white" test.mpg But the output fails to render any non-ASCII characters: Note from left to right: ＡＴ - Double spaced characters 05 - Simple numbers ーポン - CJK characters 攢ð - AltGr + a,b,c,d in my locale (en_GB.UTF-8) At first I assumed the font was at fault, but I've checked numerous fonts and they have the relevant glyphs. Indeed my entire system has no problems with these characters at all. I then assumed it must be ffmpeg but I tried the following: convert -background black -size 800x480 -fill "#ff0080" -family "Ubuntu Mono" -pointsize 72 -gravity center label:'ＡＴ 05 ーポン 攢ð' output.png The result being: So I'm back to assuming there is something wrong with my environment. I've tried on Ubuntu Trusty and Ubuntu Xenial but the results are the same. $ locale LANG=en_GB.UTF-8 LANGUAGE=en_GB:en LC_CTYPE="en_GB.UTF-8" LC_NUMERIC="en_GB.UTF-8" LC_TIME="en_GB.UTF-8" LC_COLLATE="en_GB.UTF-8" LC_MONETARY="en_GB.UTF-8" LC_MESSAGES="en_GB.UTF-8" LC_PAPER="en_GB.UTF-8" LC_NAME="en_GB.UTF-8" LC_ADDRESS="en_GB.UTF-8" LC_TELEPHONE="en_GB.UTF-8" LC_MEASUREMENT="en_GB.UTF-8" LC_IDENTIFICATION="en_GB.UTF-8" LC_ALL= $ ffmpeg ffmpeg version 3.2.4-static http://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2017 the FFmpeg developers built with gcc 5.4.1 (Debian 5.4.1-5) 20170205 configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-5 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzimg libavutil 55. 34.101 / 55. 34.101 libavcodec 57. 64.101 / 57. 64.101 libavformat 57. 56.101 / 57. 56.101 libavdevice 57. 1.100 / 57. 1.100 libavfilter 6. 65.100 / 6. 65.100 libswscale 4. 2.100 / 4. 2.100 libswresample 2. 3.100 / 2. 3.100 libpostproc 54. 1.100 / 54. 1.100 $ convert -version Version: ImageMagick 6.7.7-10 2017-05-26 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC Features: OpenMP I don't know where else to look given that my locale appears to be correct, and any font I use correctly renders the font, but when passed to either ffmpeg or convert the text shown is useless. I've done the usual hours and hours of Googling to no avail. I'm amazed nobody else has seen this problem before me. Can anyone shed any light?