Files
daedalus-fourier/docs
marfrit 480f34f6e6 Cycle 7 (H.264 IDCT 8x8) opened — Phase 1 goal doc
Predicted R7 = 0.5-0.9 YELLOW/GREEN. Closely analogous to cycle 1
(VP9 IDCT 8x8 R=0.92 GREEN): same block size, same lane geometry,
same data shape. H.264 8x8 IT uses integer butterfly with 3
sub-stages (vs cycle 1's Q14 trig single butterfly) — more
compute per pass but simpler operations.

Phase 1 documents:
- Spec butterfly (e/f/g stages per H.264 §8.5.13)
- 30fps@1080p floor = 0.972 Mblock/s (same as cycle 1 since same
  block density)
- NEON ref = ff_h264_idct8_add_neon (already vendored in
  cycle 6's h264idct_neon.S)
- Cycle 8-10 preview: chroma MC, luma qpel MC, in-loop deblock

Phase 3 next session: write column-major C ref + bench, capture
M1 + M3. Then Phase 4 plan (likely cycle-1 v3d_idct8.comp adapted
to integer butterfly), Phase 5 review, Phase 6 implement, Phase 7
measure.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-18 14:15:37 +00:00
..