3 Commits

Include renames

Author	SHA1	Message	Date
prosolis	e1aa26bb57	The 68000 decoder draws pixel-exact frames, and does not fit ... src/player/decode.s parses DLX1 and decodes straight into GVRAM. Verified pixel-exact over a 120-frame sequential run of the worst sustained window on the disc -- all four block modes, full temporal recursion, so the last frame is only right if all 120 were. In check.sh. It costs a mean of 81.7% of a 12fps frame budget, and 31% of frames exceed 100% (42% at scsi). CPU is now the binding constraint. FINDINGS 28. Three things that were believed and are not true: - The dual-display-path plan of FINDINGS 24.5/25.6 is incoherent. The compose path needs a RAM copy of the previous reconstruction; the direct path's selling point is that it keeps none. Mixing them shows stale pixels on 70 of 120 frames, worst frame 18.8% of the screen. Every coherent repair is dearer than not mixing, and 24.5's two figures were both copies with no decode in either, so there was never a crossover to find. One path ships, and the 96KB reference frame is gone. tools/analysis/10_pathmix_drift.py keeps the counterexample runnable; check.sh asserts it still reproduces. - The four block modes do not cost the same. V1 300, V4 448, RAW 400 cycles against the old model's flat 207.8. V4 is 25% of blocks and 50% of the cycles, and the mode decision charges it bytes it does not charge cycles for. tools/analysis/11_cpu_budget.py reproduces all four frames timed on the 68000 to within 1 point. Hand-derived timings agree to 0.5% on V1. - The container is big-endian but not aligned. Variable-length records laid end to end put frame 1's length field at an odd address, and move.l (a0)+ there is an address error: frame 0 decoded perfectly and then vectored into the IPL for 59 emulated seconds looking like a hang. Found by dumping PC, not by reading the source. Also: an all-V1 frame, the cheapest possible full redraw, is 110.5% of budget. No mode assignment fits a scene cut at 12fps. That one needs a decision, not a measurement. Next: charge cycles in the mode decision and bisect against 833,333 per frame, the way session 6 bisects lam against bytes -- but with no bucket, because a late frame cannot be banked. Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6	2026-08-23 15:04:38 -07:00
prosolis	497f88b945	Rate control: rebuilt per-frame, wired in, and gated at zero drift ... FINDINGS 26 stopped the session-5 rate controller before it shipped: it built a lam-ladder of independent whole-sequence encodes and picked frames off it, so SKIP blocks referenced reconstructions the decoder never saw -- 111 of 120 frames drifted. The fix is the structural one 26.1 said it had to be. vq_hybrid is now frame-drivable -- frame_ctx / decide / paint -- and encode() is a thin loop over it. Rate control drives the same three calls, bisects lam per frame under the leaky bucket, and feeds back the frame it actually emitted. The desync has no way to occur, and 09_ratectl_drift.py goes 111/120 -> 0/120. That test is now part of check.sh, which is ~2 min rather than ~40 s. Both overshoots on the worst sustained window are closed for under 1 dB, totals including audio: sasi 137.4 -> 109.5 KB/s (-0.60 dB), scsi 381.6 -> 280.0 KB/s (-0.91 dB). Zero frames hit the lam=800 cliff, so nothing was destroyed to get there. Rate control also makes the display path cheaper -- scsi's median drops 53.6% -> 47.1% -- because raising lam moves blocks to SKIP and V1. Two knobs measured rather than guessed. --rc-floor is worth 0.00 dB on that window and defaults to the profile lam, so rate control cannot regress content that already fits. --prefill defaults to 0 and is documented as a trap: it buys a permission to overshoot of exactly bucket/nframes, and on a 14-frame clip it disables the controller outright. FINDINGS 26.5 was wrong in both halves and 27.6 records it. _paint was not the bottleneck (14% of a frame, though vectorising it was still right at 17.1x) and the ladder was never "minutes" -- those were k-means in build(). What makes per-frame rate control affordable is that VQ.assign depends on neither lam nor prev, so it is cached one frame deep: a 12-step search over 120 frames costs 0.31 s against 49.1 s. Also caught: fixed-lam sasi was already 5% over target on 00020, the clip everyone called easy. Nothing noticed because the profile table quotes PSNR and not bitrate. check.sh: ALL GREEN. Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6	2026-08-23 14:36:45 -07:00
prosolis	7ba979a236	Handoff: green-light script, reconciled figures, a smaller first step for the decoder ... Prepares session 4 for handoff. No new measurements; this reconciles the docs with what session 4 changed and makes the next session's entry point cheaper. - tools/bench/check.sh re-runs both display regression tests from the Blu-ray in ~40 s and prints ALL GREEN. Verified green cold, after wiping tmp/ and re-extracting. STATUS and README both open with it, because everything downstream assumes the display path is pixel-exact and nothing previously checked that in one command. - Reconciled the figures session 4 invalidated. Session 3's 38.88 dB ceiling is struck through in STATUS with a pointer to 40.81; the "three facts the player must honour" table no longer quotes R20 = 0x0116, which was the 768-wide IPL timing and would have been copied into the player as if it were the shipping value. crtc_mode.lua is now named as the single source of truth for CRTC registers, in both STATUS and README. The 38.88 dB in the session-3 reproduce section is left alone and annotated instead: it is correct for that test, which still packs I = 1. The two numbers disagree for a reason and a reader should be able to see which is which. - Next-step 2 now leads with something smaller than "write the decoder": a dumb full-frame RAM->GVRAM blit in 68000 code, timed. That number alone confirms or kills the 38% estimate, and needs no bitstream, codebooks, or DLX1 parsing. The reference image and its checker already exist. - Parked the user's Cliff Hanger / Lupin III follow-on in STATUS so it is not lost and not mistaken for scheduled work. Cheaper than this project on every axis except media prep, which is where it would actually stall. Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6	2026-08-23 13:31:11 -07:00