I have a DAC board which accepts only right justified I2S. I know that volumio’s I2S output is I2S Phillips standard. My board doesn’t need MCLK, so I want to connect the board to RPi directly. Now I use a PCM format converter to interface them.
I’ve done the job by myself. I modified bcm2708-i2s.c and hifiberry_dac.c successfully 
Hi,
Could you please provide the modified source?
I have the same problem at hand and would love a solution.