You need (or rather it will make your life easier) if you install johnx's sbc support deb from the first post. This will allow you to enable sbc.

You can then use the default ARM encoder, or install my packages to use the DSP. The choice is yours. If someone is bored and would like to do a battey-time comparison that would be great and would either justify the use of the DSP or perhaps push me to make the code more efficient