Proposal is to use flac as audio codec. In case you have other suggestions please feel free to discuss other codecs also.
Some details about the format:
- could be played from many audio player, not so important for us, but a good feature in case beekeeper want to listen to the recordings and check the recordings also
- asymmetric codec: encoding is more expensive than decoding
- compression rate: around 50 %
- License: GNU GPL / BSD