Anyone wishing to use sox for audio file conversions on the Gumstix may be interested in this information.

While you could simply cross-compile sox using the OE environment for Gumstix, you’ll quickly learn that a number of additional dependencies are required. Here they are in the order they need to be installed (all in the OE environment):

• libogg0 >=1.1
• libvorbis >= 1.0.1
• libmad0 >= 0.15.16

I used sox-13.0.0 for my app. A few flags have changed between the various versions, but here is what I used to convert a directory full of .raw audio files to .wav files:

for i in /media/card/*.raw
do
    sox -2 -s -r 8000 -c2 $i ${i%.*}.wav
done

The flags indicate the following:

-2 sample size in bytes
-s signed-integer
-r 8000 is the sample rate
-c2 is the number of channels

Good luck! Hope it helps.