Accessing SPDIF/I2S raw data

I'm using a ADAU144x eval board to convert an SPDIF input to an I2S output.

The SPDIF input is a proprietary format with 3 data channels, each with left and right subframes. The data in each subframe contains 2 channel bits that indicate which channel it belongs to. This effectively creates 6 data channels, indexed by the 2 channel bits and the LRCLK. Some of these channels contain control data (volume, mute, etc.), and the others contain audio data (22 bits).

I would like to demux these data channels by extracting the channel bits. I also want to use the control bits to mute and change the volume of the audio channels.

Is there a way for me to directly access the raw bits of the SPDIF/I2S stream?