The (new) avcodec.dll is working correctly now
( finally!
),
and is
much faster 
than the outdated one:
Code:
[C:\AUDIOEXZ\LAB]
=>eac3to input447.dts output447.wav -libav -down16
DTS, 2.0 channels, 0:01:17, 24 bits, 447kbps, 48kHz
Decoding with libav/ffmpeg...
Reducing depth from 64 to 16 bits...
Writing WAV...
Creating file "output447.wav"...
Clipping detected, a 2nd pass will be necessary. <WARNING>
Starting 2nd pass...
Decoding with libav/ffmpeg...
Reducing depth from 64 to 16 bits...
Writing WAV...
Applying -0,13dB gain...
Creating file "output447.wav"...
eac3to processing took N ;-) seconds.
Done.
a lot,
madshi!