Convolution filtering

[JackFil]

Thank you Simon for your quick reply .

Unfortunately I tried with BubbleUPnP running on Android as renderer but I still get the exact same behavior (gap between tracks + double-speed issue)...

BUT I found what's wrong: in my case the parameter afir that causes the double-speed issue.

If I change the stream.options to:
convOut=-i /home/pi/Convolution/impulseS352.wav -lavfi "apad=pad_len=65536,apad=pad_len=65536,aresample=resampler=soxr:precision=33:cheb​y=1:dither_method=triangular"

... I don't have this issue with double speed anymore and the tracks are played gapless !

My assomption is that the last version of ffmpeg available for Buster/raspberry (4.1.6-1) does not support the afir parameter.

I'll wait...