2 Commits

Include renames

Author	SHA1	Message	Date
prosolis	06b98d4b47	Price cycles in the mode decision: 37 misses become 1, for 0.26 dB ... The decoder has been CPU-bound since FINDINGS 28 while the mode decision minimised D + lam*R -- distortion against BYTES. decide() now minimises D + lam*bytes + mu*cycles, and ratectl bisects mu per frame against the 833,333-cycle budget with the lam bisection nested inside it. On the worst sustained window: sasi 27.22 -> 26.95 dB, 109.5 -> 109.4 KB/s, 37/120 misses -> 1 scsi 29.90 -> 29.27 dB, 280.0 -> 278.6 KB/s, 51/120 misses -> 1 Bitrate does not move: the byte controller still binds, and mu changes WHICH modes are bought. V4 is what it stops buying -- 25.2 -> 20.3% of blocks at sasi and 15.0 -> 5.3% at scsi, where RAW takes it. That is 28.8's inversion in practice: RAW is dearer in bytes and cheaper in cycles, so only the byte-rich profile can buy its way out of V4. Three things worth knowing beyond the headline: - The one frame that still misses, at both profiles, is FRAME 0 -- no previous reconstruction, so 100% changed by definition, which is also what a scene cut is. It comes out at the all-V1 floor of 110.6% and is emitted late on purpose. Freezing a cut to make a deadline is the worse failure. - 28.7's "11 frames are impossible" was too pessimistic. That floor held the SKIP set fixed and asked how cheaply the drawn blocks could be drawn; the real decision can also MOVE a block to SKIP, which above ~90% non-SKIP is the only lever left. - SKIP's price depends on its neighbours (13.25 cycles clustered, 45 mixed), which a per-block lagrangian cannot see. The way out is that the two uses need not share a cost function: a ranking constant inside decide(), the exact clustered rule for the frame-level bisection. vq_hybrid.cycles() is now the one definition of that rule and 11_cpu_budget.py imports it. Gated: 09_ratectl_drift.py runs both controllers, both 0/120 drifting frames. The cost-aware container decodes pixel-exact on the 68000 (120 frames). ON by default in encode.py; --no-cpu-fit restores session 7. check.sh ALL GREEN. Still a model, not a measurement, for THIS container: FINDINGS 31's cycle figures come from vq_hybrid.cycles (within 1 point of the 68000 on four frames of the session-7 container). Timing this one on the machine is step 1 of the next session -- it was started and killed for time, and it is slow. FINDINGS 31. tools/analysis/13_cpu_ratectl.py. Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6	2026-08-23 16:24:22 -07:00
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