Q42 AcousticPlane — Internal Draft Standard

Version: 0.1.1 (draft)
Date: 2026-08-15
Status: Internal draft — not submitted externally
Branch: 0.0.30
Normative code: crates/qualia-core-db/src/audio/ (acoustic_plane.rs, acoustic_sab.rs, audio_spectral_sheet.rs), crates/qualia-core-db/src/net/sonic_token.rs, crates/qualia-core-db/src/render/acoustic.rs

This is a U3 binary contract, not a Q42 volume layout. It does not encode NQuins and is not affected by five-field SuperBlock ECC. Sizes below (8-byte token, 328-byte uniform, 1024-byte SAB, 20-byte Q4AU header) are unchanged.

Abstract

This draft defines the U3 AcousticPlane binary contracts for Qualia WASM: 64-bit Sonic Tokens, the AcousticUniform worklet payload, the 1024-byte SharedArrayBuffer (Q3AS) layout, and the phenomenal σ parity mapping shared with the visual spectral pipeline. It does not define LLM waveform generation — U0 emits structure (tokens), never PCM.

1. Scope & non-goals

In scope

• Hot-path symbolic events (Sonic Tokens)
• Parametric synthesis driven by Tensor10D SOA
• Binaural staging from tensor position + camera yaw
• Cold STFT sidecar header (Q4AU v1) and additive v2 planes (mel + MFCC)
• CQT mmap kind (SIDECAR_KIND_CQT in header _pad)
• Browser transport (SAB + float mirror)

Out of scope (v0.1)

• KEMAR HRTF table assets (analytic head model only)
• MP3/AAC as storage truth
• Neural audio from U0

2. Compute universe placement

3. Sonic Token (64 bits)

Size: 8 bytes (#[repr(C)], Pod).
Magic flag: 0x0053 ('S') in bits 48–63 for validated events.

3.1 Bit layout

Bits     Width   Field
──────────────────────────────────────
[0..7]     8     delta_time
[8..11]    4     event_type
[12..15]   4     channel
[16..23]   8     note
[24..31]   8     velocity
[32..47]  16     tensor_index
[48..63]  16     flags (SONIC_MAGIC = 0x53 in low byte)

3.2 Event types

3.3 Encoding (reference)

raw = delta_time
    | ((event_type & 0x0f) << 8)
    | ((channel & 0x0f) << 12)
    | ((note as u64) << 16)
    | ((velocity as u64) << 24)
    | ((tensor_index as u64 & 0xffff) << 32)
    | ((flags as u64 & 0xffff) << 48);

3.4 Transport

• Ring: process-local SPSC (SonicTokenRing in acoustic_plane.rs): UnsafeCell<[u64; 128]> + AtomicU32 write/read sequences. Capacity SONIC_RING_CAP = 128. This is not the rtrb logit/control rings used by Phase 8 inference.
• Drain: drain_sonic_tokens(&mut [u64]) → count written; WASM drain_sonic_tokens(max) → JS array of u64
• SAB slots: 16 × 8 B at offset 384 (see §5)

4. AcousticUniform (328 bytes)

Alignment: 4-byte (f32 fields).
Float export count: 82 = 18 scalars + 64 preview bins.

4.1 C struct (logical)

#[repr(C)]
pub struct AcousticUniform {
    pub alpha: f32,
    pub mu: f32,
    pub position: [f32; 3],
    pub track_v: f32,
    pub manifold_w: f32,
    pub epistemic_q: f32,
    pub fm_index: f32,
    pub frequency_hz: f32,
    pub enabled: u32,
    pub gain_l: f32,
    pub gain_r: f32,
    pub itd_seconds: f32,
    pub azimuth_rad: f32,
    pub elevation_rad: f32,
    pub room_damp: f32,
    pub stft_frame: f32,
    pub preview_bins: [f32; 64],
}

size_of::<AcousticUniform>() == 328.

4.2 Binaural fields

Populated by apply_binaural_to_uniform(uniform, listener_yaw):

• Source: position from tensor (x, y, z)
• Listener yaw: portal camera yaw (radians)
• Model: analytic ITD/ILD (audio/hrtf.rs) — not KEMAR tables in v0.1

5. Acoustic SharedArrayBuffer (Q3AS, 1024 bytes)

Magic: 0x5133_4153 ("Q3AS")
Version: 1

5.1 Header fields

Worklet polls uniform_seq (offset 6, u16 LE) against last seen sequence.

6. Phenomenal σ parity

Shared fractal wavelength:

fract(σ) = σ - floor(σ)
λ_nm     = 400 + fract(σ) × 300        // 400–700 nm
t        = clamp((λ_nm - 400) / 300, 0, 1)
f_hz     = clamp(1760 × (1 - t) + 110 × t, 55, 8000)

Visual twin: portal_spectral::sigma_to_cie_xyz(σ) uses the same λ band.
Auditory carrier: phenomenal_voice_frequency_hz blends f_hz (72%) with bin-peak heuristic (28%).

Invariant: f_hz(σ) == f_hz(σ + n) for integer n.

7. Spectral sidecar header (Q4AU, 20 bytes)

#[repr(C)]
pub struct AudioSpectralSidecarHeader {
    pub magic: u32,       // 0x5134_4155 "Q4AU"
    pub version: u16,     // 1 = plane-0 only; 2 = plane-0 + appended v2 planes
    pub _pad: u16,        // SIDECAR_KIND_STFT = 0, SIDECAR_KIND_CQT = 1
    pub bin_count: u32,   // typically 64
    pub frame_count: u32,
    pub sample_rate: u32, // typically 48000
}
// v1 payload: frame_count × bin_count × f32 LE  (plane-0)

version == 1 remains valid. version == 2 does not change the 20-byte header or plane-0 layout. After plane-0, v2 appends:

SpectralV2SubHeader (12 B): magic 0x324D_3451 "Q4M2", n_mel u32, n_mfcc u32
mel plane:  frame_count × n_mel  × f32 LE
MFCC plane: frame_count × n_mfcc × f32 LE

Cold bake: bake_stft_sidecar_demo(frames) / bake_cqt_sidecar_demo(frames) in portal WASM; native bake_spectral_v2_from_samples. mmap path: {storage}/spectral/audio/{hash}.bin.

8. Conformance

Implementations MUST:

1. Keep hot-path audio APIs zero-heap (&mut [T] out buffers).
2. Never store MP3/AAC as semantic truth — sheets + tokens only.
3. Preserve σ parity formulas byte-identical to audio/acoustic_plane.rs oracles.
4. Reject SAB buffers whose byteLength !== 1024.

Test vectors

cargo test -p qualia-core-db audio:: --lib
cargo test -p qualia-core-db phenomenal_hrtf phenomenal_sigma_visual_audio_parity --lib
node docs/tests/phenomenal-verify.mjs

9. Changelog

See standards-backlog.md for external submission timeline.