I have downloaded several webm and m4a files from youtube, each of them is without video but with audio track. Now I wish to convert them into OPUS, with settings optimized for audiobooks. So I tried it using SoundConverter, installed on Xenial: it failed with following settings:
format: .opus ; quality: "very low" ; resample: 22050 Hz (better: below) ; channels: mono ; resulting target bitrate: around 48 kbps (better 32 kbps)
Even the suggested bug fix does not help. So I did check for an updated software version:
Installation of the package soundconverter from the xenial/universe software source:
But then in SoundConverter's Menu/Help/About it claims to be an older version:
There is no PPA source for sound converter.