[jjd-uk]

That's the point, there is no resampling going on, all that happens is that the orignal 16 bit signal is simply padded with zero's to create a 24 bit output, so the orignal 16 bit is still contained untouched within the 24 bit output.

This explains why 16 bit as 24 bit is still bitperfect https://wiki.jriver.com/index.php/Audio_...Conversion