Reading Line-In instead of Mic In on the DE1

I am trying to get a basic set up where I can read a signal in through Line-in, do some basic / arbitrary processing, and send it to Line-out. However, I am only able to read from Mic in, which is less than desirable as (as far as I'm aware) it cannot take a stereo input. I am using the audio codec provided here: ftp://ftp.altera.com/up/pub/altera_material/13.1/laboratory_exercises/digital_logic/de1-soc/vhdl/lab12_design_files.zip

When tracing through this code, I was unable to determine where to set the signal to be read from Line-in instead of Mic in. My hunch is that it has something to do with the audio_and_video_config.v parameters, but I am unable to make sense of the values.

Any help would be greatly appreciated!