I\'ve got what seems like it should be a really simple problem, but it\'s proving much harder than I expected. Here\'s the issue:
I\'ve got a fairly large image seq
check your version of ffmpeg
ffmpeg -version
ffmpeg version n4.1.4 Copyright (c) 2000-2019 the FFmpeg developers built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
you'll need to update to v4 for alpha support use
sudo snap install ffmpeg
N.B. you'll need to ditch the old ffmpeg from your system.
sudo apt-get remove ffmpeg
ffmpeg -version
ffmpeg version n4.1.4 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
configuration: --prefix= --prefix=/usr --disable-debug --disable-doc --disable-static --enable-avisynth --enable-cuda --enable-cuvid --enable-libdrm --enable-ffplay --enable-gnutls --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfontconfig --enable-libfreetype --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopus --enable-libpulse --enable-sdl2 --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxvid --enable-nonfree --enable-nvenc --enable-omx --enable-openal --enable-opencl --enable-runtime-cpudetect --enable-shared --enable-vaapi --enable-vdpau --enable-version3 --enable-xlib
libavutil 56. 22.100 / 56. 22.100
libavcodec 58. 35.100 / 58. 35.100
libavformat 58. 20.100 / 58. 20.100
libavdevice 58. 5.100 / 58. 5.100
libavfilter 7. 40.101 / 7. 40.101
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
N.B. - you can hide the above from constantly appearing every time you run ffmpeg by passing
-hide_banner