uhm... as i suspected piping thru "|" doesnt work...
the proof is here:
http://www.webalice.it/f.corriga/sng/sng_0.3b_src.7z
(needs bepipe.exe in the same dir as sng.exe. the code contains also the -2pass fix and some aesthetic fixes as well).
any idea is welcome but i think an intermediate file is needed (using avs2wav) since i dont know how piping works in pascal...