libavfilter-extra6 7:3.3.4-2build1 (amd64 binary) in ubuntu bionic

 FFmpeg is the leading multimedia framework, able to decode, encode, transcode,
 mux, demux, stream, filter and play pretty much anything that humans and
 machines have created. It supports the most obscure ancient formats up to the
 cutting edge.
 .
 This library provides a generic audio/video filtering framework containing
 several filters, sources and sinks.
 .
 This package replaces the libavfilter6 package and contains the
 following additional filters:
 .
  * Optical Character Recognition (uses Tesseract)
  * SOFAlizer (Spatially Oriented Format for Acoustics, uses netcdf)
 .
 Because this package links against libraries that are licensed under
 Apache License 2.0, the resulting binaries are distributed under the
 GPL version 3 or later.