atracdenc, branch new_psy

atrac3: reimplement tonal encoding. Use flatness-based tonal extraction

2026-04-19T22:27:45Z

- Add shared CalcSpectralFlatnessPerBfu helper in atrac_psy_common with BFU-table mapping. - Implement ATRAC3 tonal extraction: compute MDCT energy, estimate per-BFU flatness, extract up to 5-bin strongest tonal run in low-flatness BFUs, and zero extracted bins in residual. - Map extracted tonal bins into TTonalBlocks and integrate them into bitstream coding. - Update ATRAC3 bit allocation - reduce residual bits for BFUs with tonal blocks, and increase tonal quantizer selection. - Restore --notonal CLI option in main.cpp for A/B comparison.

[AT3] refactor bitstream allocation loop to bs_encode

2026-04-11T21:20:06Z

Remove dead transient hooks, hack override, and unused RMS helper

2026-04-09T19:39:52Z

Merge new_psy -> master

2026-04-08T22:24:50Z

New experimental gain control code for atrac3

Fix Windows C++17 build and MSVC flag warnings

2026-04-08T22:12:05Z

atrac3: add boundary transient thresholding to prune low-value gain transitions

2026-04-08T21:33:40Z

Problem Gain curve generation emitted many +/-1 level transitions that do not correspond to strong local transients. These points consume gain-info bits and can create low-level modulation artifacts without improving transient handling. Solution Introduce explicit transient evidence gating at transition boundaries in CalcCurve(), and wire it to the existing dynamic min-score path. What changed - Added BoundaryTransientScore(env, loc, win): - computes local ratio around each subframe boundary - R = max(max_right/max_left, max_left/max_right) - short symmetric window (win=3 subframes) - Re-enabled minScore usage in CalcCurve() (previously ignored). - For each level transition candidate at loc=sf+1: - keep unconditionally if loc==targetSf (tail neutral anchor) - keep unconditionally if |deltaLevel| >= 2 (strong step) - otherwise keep only if BoundaryTransientScore(loc) >= minScore - Added YAML telemetry: - transient_min_score - transient_window - transition_pruned {loc, delta, score} Why this is safe - Strong transitions are preserved. - Rightmost transition is preserved to keep proper return-to-neutral anchoring. - Only low-confidence small toggles are removed. Measured impact (current branch comparison) Baseline: ea4d33b38 (before this change) Tracks: show_me_your_spine.wav, 13.wav Gain-info bits / points: - spine: 191,697 -> 150,297 bits (delta -41,400; -21.6%) 15,593 -> 10,993 points (delta -4,600) - 13.wav: 1,299,035 -> 979,931 bits (delta -319,104; -24.6%) 97,035 -> 61,579 points (delta -35,456) Subjective note User listening reports improved sound and fixes for some low-level artifacts.

atrac3: remove band3 transient boost redirection to band0

2026-04-08T21:33:40Z

atrac3: make sticky gain quantization conditional and tune thresholds

2026-04-08T21:33:40Z

Problem The distribution-aware sticky quantizer reduced gain-curve bitrate, but in some release/transient frames it over-merged nearby transitions. On spine around 17.657s (ch1/band2), this collapsed the curve shape and could produce an audible spike. What changed - Added frame-level sticky eligibility gating in CalcCurve(). - Sticky is now enabled only when both conditions hold: - intra-frame ratio is limited: max_gain / target <= kStickyMaxIntraFrameRatio - inter-frame target jump is limited: prev_target / target (symmetric) <= kStickyMaxInterFrameRatio - Added local uncertainty guard for sticky hold: - require idx span from [subframeLow, subframeHigh] quantization to be narrow (idxSpan <= 1) before allowing prev-level hold. - Added YAML diagnostics per band/frame to make gating decisions auditable: - sticky_frame_eligible - sticky_intra_ratio - sticky_inter_ratio Threshold tuning Swept candidate pairs on both tracks: - show_me_your_spine.wav - 13.wav Pairs tested: (5,6), (5,8), (6,8), (6,10), (7,8), (7,10), (8,12) Selected: - kStickyMaxIntraFrameRatio = 7.0 - kStickyMaxInterFrameRatio = 10.0 Reason for selection - Keeps safety behavior on known failure site: frame 760, ch1, band2 remains sticky_frame_eligible=false and retains non-collapsed curve shape (loc 1,2,5,7). - Improves gain-modulation bitrate vs previous 6/8 tuning while avoiding fully open behavior. Measured gain-modulation bits (spine + 13.wav) - 6/8: 1,493,639 bits - 7/10: 1,490,732 bits (selected, -2,907 bits vs 6/8) - 8/12: 1,488,824 bits (lowest in sweep; not selected to keep extra margin)

atrac3: add distribution-aware sticky gain quantization

2026-04-08T21:33:40Z

Problem Gain curve construction still produced many +/-1 level toggles across long runs (e.g. 7<->8 chatter). These transitions are usually quantization noise from subframe-level RMS rounding, not real envelope changes, and they consume gain bit budget without improving transient protection. Feature Introduce distribution-aware sticky quantization for subframe gain levels. Instead of quantizing only the subframe centre estimate, we also track a robust within-subframe range and suppress one-step toggles when the previous level is still consistent with that range. Implementation 1) AnalyzeGain now optionally returns per-subframe low/high energy estimates (robust inter-quantile bounds from micro-chunk analysis inside each subframe). 2) CalcCurve now accepts optional subframe low/high vectors. 3) During sfLevel quantization: - compute centre level via RelationToIdx(filtered/target) - if new level differs from previous by exactly 1, and previous level is still inside [idx(low), idx(high)], keep previous level (sticky hold) 4) CreateSubbandInfo wires the new AnalyzeGain outputs into CalcCurve. 5) Existing point0 guard/boundary logic remains intact; this feature operates earlier at sfLevel formation. Why this is safe - Only suppresses +/-1 oscillation when previous level is still supported by observed subframe distribution. - Does not clamp large transitions or remove structurally important points. - Keeps curve scan/priority flow unchanged after sfLevel is formed. Measured impact on current HEAD (gain-info bits) Bit accounting uses ATRAC3 gain syntax: per channel header + per band point-count fields + 9 bits per gain point. show_me_your_spine.wav: - base: 219,552 bits (18,688 points) - with sticky: 172,158 bits (13,422 points) - saved: 47,394 bits, 5,266 points (-21.59% gain-info bits) 13.wav: - base: 1,537,724 bits (123,556 points) - with sticky: 1,146,746 bits (80,114 points) - saved: 390,978 bits, 43,442 points (-25.43% gain-info bits)

atrac3: make point0 guard boundary-aware to avoid overlap artifacts

2026-04-08T21:33:40Z

Problem The current point0 guard decides keep/revert only from an early-frame mismatch score. That can revert a newly inserted point0 even when it is needed for frame-boundary continuity. In ATRAC3 demodulation, the next frame's first gain level is reused as a scale term for the overlap region, so removing point0 can change boundary scale by multiple quantization steps and create audible artifacts. Root cause For frames like 13.wav around 45.1s, point0_guard reverted point0 in key bands, which changed first-point scale and increased boundary mismatch despite a locally better early-fit score. Change - Keep existing early mismatch metric (fit + leakage proxy). - Add boundary-aware keep criterion inside point0_guard: * compute desired boundary scale in the same HPF domain: desiredScale = LimitRel(prevTarget / hpfRmsNextMod) * compare log2 distance of first-level scale before/after point0 insertion * if point0 reduces boundary error by a material margin (0.2 bits), force keep even when early-fit score slightly worsens - Apply guard only when point0 actually changes the curve. - Add YAML telemetry for boundary error before/after to support analysis. Implementation details - Added helper utilities to reconstruct subframe-average divisors from curve points and score early mismatch consistently. - Updated point0 insertion/update flow to track whether point0 changed. - Extended guard decision to combine: * early mismatch tolerance (existing behavior), and * boundary continuity improvement (new behavior). Observed effect (focused check) - On 13 clip (~45.1s), exact bad subframe (t=45.103129s, frame256=7769, sf32=23): ratio vs no-gain reduced from 9.30x to 1.51x after this change. - Frame 1942 YAML now shows point0 kept in bands where boundary error drops substantially. Notes - No full regression run in this commit (intentional for fast iteration).