Function centered_qp 

fn centered_qp(bit_depth: u32) -> u32

The quantizer a constant-rate slice names where the rate control codes its own in every coding unit as a delta from the slice’s (Intel’s full encoder): the middle of the range at bit_depth, from which a delta within the syntax’s -(26 + QpBdOffsetY / 2) to 25 + QpBdOffsetY / 2 reaches every quantizer. From 30, a unit the rate control takes under 4 codes a delta past that range, which a strict decoder refuses and a lenient one decodes as garbage.