  * provide library-related binary packages
  * enable modules GZRTP and ZRTP:
    + build-depend on libgzrtp-dev and/or libzrtpcpp-dev
    + mention ZRTP in long descriptions
  * enable module AV1:
    + build-depend on recent enough libaom-dev
    + mention AV1 in long descriptions
  * enable module PCP:
    + build-depend on librew-dev <https://github.com/alfredh/rew>
    + mention PCP in long descriptions
  * enable modules iLBC, iSAC and WebRTC AEC:
    + build-depend on recent enough libwebrtc-audio-processing-dev
    + mention WebRTC AEC in long descriptions
