nx_vp8_kf.nx

nx_vp8_kf.nx -- VP8 lossy KEYFRAME decoder (intra-only): the C3 rung. Entropy half + driver. Bitstream order and all probability plumbing ported against RFC 6386 reference decoder (dixie.c / modemv.c / tokens.c): partition-1 header: colorspace(2b, must be 0) -> segmentation -> loopfilter (parsed, v1 does not filter) -> token partition count+sizes -> quantizer -> refresh_entropy -> 1056 coeff prob updates -> skip prob. Then one mode pass over all MBs (partition 1), then per-row token decode (partitions cycle by row) + reconstruction. THE LOOP FILTER IS DELIBERATELY ABSENT (fingerprint-grade output): it smooths block edges for display but does not feed back into intra prediction of the same frame, so omitting it perturbs pixels only locally. The gate bounds the perturbation against an independent oracle. TOKEN CONTEXT RULES (the three easy-to-lose ones, from tokens.c): - EOB is NOT tested for the token following a ZERO token. - After a token, the next context is 0/1/2 for zero/one/bigger. - A skipped MB zeroes its left+above contexts EXCEPT Y2 when the mode has no Y2 block (B_PRED), which PRESERVES the stored Y2 context. genealogy_id: vp8_rfc6386 lineage_id: nx_vp8_kf_v1 license_tier: ORIGINAL