audio samples are standard Well perhaps this has come from SD SDI television standards where standard AES audio packets are limited to 20 bit audio Extended Data Packets can follow standard 20bit audio packets in SD SDI these contain an extra four AES auxiliary bits which can be used for 24bit audio In HD SDI and better Audio Data Packets are 24bit as standard Of course the four least significant bits will be zero padded if presented with a 20bit PCM source Matt Avent 2013 Protocol section says that 20 bit