i2s to parallel conversion

I need to handle a S/PDIF decoded stream (i2s from a Crystal decoder) in a Microchip PIC or AVR microcontroller and so thought a shift register with a little support logic could transform the serial i2s data to two sets of parallel data (16 bit - one set for each channel)and would free up a lot of time for the microcontroller. Has anyone done this or advise against this?
Thanks, Jeff
Thanks for the quick responses.

Sync40 - another PIC is what I have planned. The sampling rate will be 48KHz - 16Bit and so figured I would alot 4 addressable registers to hold these values and pass them parallel to the operating PIC.

gmarsh - I have not considered these - thanks. I am a bit leary of learning yet another system (software and hardware) but will if the application fits. Time to read the data sheets...