The transcoding script will end up being called like this:
mt-daapd-ssc.sh "/path/to/oggfile.ogg" 0 0
Or close enough. Run that by hand and see what you get. You should get a wav file on stdout.
Your problems are one of the following:
1. mt-daapd-ssc.sh isn’t producing a valid wav output. Test it by manually running, redirecting stdout to a file, and playing the file with a media player. If it works, that’s not the problem.
2. your ssc_script path in your config file isn’t right
3. that’s about all it could be, given the log. 🙂