A lot of questions on previous background. DSP basics and they will ask you to come up with block diagrams of AVR systems even if you dont know everything just to check your thinking approach.
A lot of questions about perceptual coding,ac3 and dolby proprietary stuff,it will be good to know them but they understand that you may not know everything.
Really nice experience,really professional and a great bunch of people. Company looks awesome,good culture and very good interview process