nx_h264_bits.nx

nx_h264_bits.nx -- H.264 bitstream reader + Exp-Golomb (rung 2 keystone). EVERY field in H.264 SPS/PPS/slice headers is coded as ue(v) (unsigned Exp-Golomb) or se(v) (signed), read MSB-first. This is THE primitive the whole decoder stands on -- so it is built and KAT-gated against the canonical Exp-Golomb code words before anything above it is attempted. ue(v): count leadingZeros z (zeros before the first 1, which is consumed), read z more bits 'rest', value = (1<<z) - 1 + rest. codeword "1"->0, "010"->1, "011"->2, "00100"->3, "00101"->4 ... se(v): map k=ue(v): 0->0, 1->+1, 2->-1, 3->+2, 4->-2 (sign + ceil(k/2)). genealogy_id: itu_t_h264_annexB_exp_golomb + teuhola_1978_exp_golomb lineage_id: msb_bitreader + ue_se_exp_golomb license_tier: ORIGINAL