command line stream MP3 to wave?

[AlanHK]

I want to convert a bunch of MP3s to AC3.

I know there are other encoders, but I would like to use Aften, which takes wave input.

And ideally, I would like to stream the MP3 into Aften rather than making a lot of large WAVE files.
Is there something that streams MP3 to wave so I can make a batch file like:

for %%I in (*.mp3) do (
MP3wave %%I - | p:\aften\aften.exe - %%~nI.ac3
)

I tried BeSweet, but it does not seem able to stream its output. Using
" -output - "
just created a file called "-".

[tebasuna51]

You can use Lame.exe:

for %%I in (*.mp3) do lame --decode "%%I" - | aften.exe - "%%I.ac3"