libavcodec-dev 7:4.2.2-1ubuntu1 (riscv64 binary) in ubuntu focal

 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 encoding/decoding framework and
 contains multiple decoders and encoders for audio, video and subtitle streams,
 and several bitstream filters.
 .
 The shared architecture provides various services ranging from bit stream I/O
 to DSP optimizations, and makes it suitable for implementing robust and fast
 codecs as well as for experimentation.
 .
 This package contains the development files.