An ADPCM block whose flags carry END (bit 0) but not REPEAT (bit 1)
must (a) jump the decode pointer to the latched repeat address and
(b) force the ADSR envelope to ZERO on entering Release — Beetle
spu.cpp:333 (CurAddr = LoopAddr, unconditional) and :341-352 ("Force
enveloping to 0 if not looping"). Our voice_next_sample did neither:
it entered Release with the envelope intact and kept decoding FORWARD
past the terminator, assuming the release ramp would mask whatever
followed in SPU RAM.
X4's SFX bank breaks that assumption three ways: its one-shot samples
terminate on an END-only block; the next block in RAM is non-silent
filler (0x77 nibbles at shift 0 = constant +28672) carrying a
self-referential LOOPSTART flag, so the walker parks there forever;
and the bank's ADSR release shift is ~infinite, so the envelope never
decays. Every finished SFX voice became a full-scale DC source. In the
X4 attract ice-stage demo (user report), a handful of ice-block-break
SFX stacked ~15 such voices and pinned the whole mix at +32767 for
~35 s — heard as static / the music "cutting out". Measured: 38-41%
of samples hard-clipped in the spu_out AND host taps during the demo.
With the fix (jump + env=0; the env-0 Release path then deactivates
the voice, matching Beetle's silent-voice behavior): 0.00% clipped
samples over the same demo window, peak 32291, zero railed polls in
150 across the full attract cycle; the ice-crack SFX bodies still
play normally.
Found via the new rail-triggered spu_voices capture + the spu_ram
peek: 15 voices sharing start=0x16AD0 all parked at cur_addr=0x17930
looping 0x17920 (flags 0x07) at env 0x7FBF in phase RELEASE, and the
block bytes 00 07 77 77 .. decoding to +28672 DC.
Debug surface added (always-on doctrine):
- spu_voices now reports live env level + ADSR phase per voice.
- new spu_ram command: {"addr","len"} -> hex peek of SPU sample RAM.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
SPU Catmull-Rom float shadow (spu_shadow), 15-bit CRT color LUT (raw bit-exact), verifier. Opt-in (env-gated), default OFF: raw output byte-identical and remains the verify oracle. Reverts loud (DEGRADED) on divergence. ShadowVerifier ported from JRickey/gba-recomp (MIT OR Apache-2.0). Compiles clean; full game-build A/B is the remaining integration gate.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The "v4" suffix was a holdover from iterative project restarts.
There is now one psxrecomp; all identifiers, include guards, cmake
variables, function names, log strings, schema tags, and tool paths
drop the v4 suffix.
Changes:
- PSXRECOMP_V4_ROOT → PSXRECOMP_ROOT (cmake)
- PSXRECOMP_V4_RUNTIME_SOURCES/_INCLUDE_DIRS/_BIOS_GENERATED → no V4
- psxrecomp_v4_add_runtime_target → psxrecomp_add_runtime_target
- PSXRECOMP_V4_*_H include guards → PSXRECOMP_*_H
- "psxrecomp-v4" log/window strings → "psxrecomp"
- Schema version strings in recompiler JSON output
- Tool script hardcoded absolute paths updated
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
Root cause: BIOS music engine reads voice register 6 (byte offset 0x0C,
CURVOL / ADSR_LEVEL) to find a free voice; recomp returned the never-
written spu_regs value (always 0), so the engine saw every voice as
silent and over-recycled voices 0-3 instead of fanning across all 24.
After fix, recomp KEYON-per-voice counts match Beetle exactly (e.g.
v0 2/2, v18 2/2, v22 1/1).
Also:
- Full ADSR envelope (Attack/Decay/Sustain/Release) ported from Beetle's
CalcVCDelta/RunEnvelope. KEYOFF now triggers Release-phase decay
rather than immediate silencing.
- End-without-loop triggers Release (matches RunDecoder), not active=0.
- ENDX latch at 0x1F801D9C/9E now reports actual block-end-reached
state instead of active-mask.
- SPU event ring (KEYON/KEYOFF/END_STOP/END_LOOP) on both backends with
frame-stamped per-voice payload; 1 M entries each (32 MB) for chime +
game-scene headroom. Beetle-side env>0 filter so silent-loop noise
doesn't bury the audible-voice timeline (matches recomp behavior
where deactivated voices don't fire further events).
- spu_voices / spu_events / spu_events_reset debug-server commands on
both ports. send_fmt buffer kept single-shot to avoid extra newlines.
- tools/_spu_ring_diff.py: frame-aligned event-ring diff with per-voice
count summary; chunk-count cap removed (was aborting reads at 98 KB).
- tools/_spu_capture.py, _spu_probe.py, _probe_one.py: targeted probes
used during diagnosis.
Local-only beetle-psx change (gitignored): same env>0 filter at
mednafen/psx/spu.cpp around line 345/352. Rebuild beetle-psx static
lib if reapplying.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
CDROM (adapted from v3, 487 lines):
- Removed event_deliver() — HLE disease. IRQ delivery is now purely
via i_stat bit 2; the recompiled BIOS exception handler processes
CDROM events natively through its own EvCB table.
- Removed CPUState* from all function signatures — hardware registers
don't need CPU state.
- Removed hard-coded RAM writes (0x800DEE54 etc.) — BIOS kernel state
manipulation disguised as hardware sim.
- Removed all fprintf.
- Kept: register banking, command processing, sector reads, DMA interface.
SPU (new, 89 lines, register map from v2 reference):
- Accepts all SPU register reads/writes at 0x1F801C00-0x1F801FFF
- 512KB SPU RAM with transfer address tracking and FIFO writes
- DMA4 write interface for bulk transfers
- SPUSTAT returns 0 (ready, not busy)
- No audio synthesis — placeholder for SDL_audio integration later
Memory.c: replaced inline spu_regs[] array and stub CDROM handlers
with calls to the proper cdrom.c and spu.c modules.
Validated: BIOS boots identically (16,859 GP0 writes, 1,149 draws).
No regression from previous commit.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Matthew Stanley