I actually switched back to debian from Funtoo/Gentoo where the whole ffmpeg/avconv discussion can sometimes get a little 'heated'
I had been away from debian so long that I forgot about the preference for libav-tools.
But yes, absolutely true: both can be used in the scripts above, i actually have both
installed (via @deb-multimedia.org repo).
As the trend is towards libav-tools and away from ffmpeg 'real' i thought it a good idea to go with the previous suggestion to update the simple guide to avconv.