speexenc/speexdec doubles file size

Juha Heinanen writes:

> any idea why size of wav file doubles when it is encoded to speex and
> back to wav:
> 
> $ ls -ls testi.wav 
> 40 -rw-r--r-- 1 foo foo 40674 May  4 14:38 testi.wav
> 
> $ speexenc --denoise --agc --quality 10 testi.wav testi.spx
> Encoding 8000 Hz audio using narrowband mode (mono)
> 
> $ ls -ls testi.spx
> 20 -rw-r--r-- 1 foo foo 16405 May  4 14:46 testi.spx
> 
> $ speexdec --mono --rate 8000 testi.spx testi.wav
> Decoding 8000 Hz audio using narrowband mode (mono)
> Encoded with Speex 1.2rc1
> 
> $ ls -ls testi.wav 
> 84 -rw-r--r-- 1 foo foo 81464 May  4 14:48 testi.wav

i guess the answer is that wav file produced by speexdec is 16 bit when
the input wav file to speexenc was 8 bit.  if i use sox to convert the
output wav file from 16 bit to 8 bit, audio quality gets really bad.

-- juha