32bit output into 24bit capable soundcard. How bitdepth is converted i Options

[amiti]

When streaming an audio data of 32bit to a 24bit capable soundcard via ASIO, how does the hardware/drivers handle it? Are the excess bits truncated or dithered?

(I use ESI Juli@ souncard)

[nu774]

Simple right shift results in tiny negative DC offset, but this can be easily killed by the following (this is equivalent to adding 0.5 on float->int rounding):

CODE

(sample + 128) >> 8

However, as a result of addition, the resulting value can exceed maximum value in the target bits.
Therefore, some kind of saturated arithmetic (clipping) is required.