feat(processor): adopt source-rate anlmdn defaults from matrix spike

Drop the 32 kHz pre-anlmdn sample-rate cap and exit-restore aformat
clauses; run anlmdn at the source sample rate with r=0.0020 (r_min)
and m=3 (m_strict). Downstream filters (gate, LA-2A, de-esser,
analysis) now operate at the source rate throughout.

- Remove NoiseRemovePreSampleRate field and all cap-related plumbing
- Update production constants: ResearchSec 0.0045 -> 0.0020, Smooth 11
  -> 3
- Replace anlmdn_sr_32000 / anlmdn_sr_32000_best_r benchmark variants
  with anlmdn_production_current
- Drop TestAnlmdnBenchmarkPreSampleRateSpecs; assert no aformat
  sample-rate clauses appear in the noise-removal sub-block
- Add scripts/anlmdn-matrix-spike.sh to map the speed/quality frontier
  across two voice fixtures with different noise profiles
- Update AGENTS.md, README.md, Levelator gap analysis, and report
  formatter to reflect the new defaults

The matrix spike validated the new path against the previous 32 kHz cap
default at ~35% faster Pass 2 with metric-equivalent quality.

Signed-off-by: Martin Wimpress <code@wimpress.io>

Author: flexiondotorg

AGENTS.md

@@ -65,12 +65,12 @@ internal/
 
 **Filter chain order (Pass 2):**
 ```
-downmix → ds201_highpass → ds201_lowpass → noiseremove (32 kHz pre-anlmdn, r=0.0045 + compand) → ds201_gate → la2a_compressor → deesser → analysis → resample
+downmix → ds201_highpass → ds201_lowpass → noiseremove (anlmdn at source rate, r=0.0020, m=3 + compand) → ds201_gate → la2a_compressor → deesser → analysis → resample
 ```
 
 Order rationale: downmix to mono first; HP/LP removes frequency extremes before gate (DS201 frequency-conscious side-chain pattern); denoising before gating (lowers noise floor for gate); compression before de-essing (compression emphasises sibilance); analysis measures processed signal; final resample standardises output format last.
 
-**Noise removal default:** Production uses `anlmdn_sr_32000_best_r`: resample to 32 kHz before `anlmdn`, use `r=0.0045`, then continue through compand. In benchmark context, refer to the old production path as `anlmdn_legacy_default`.
+**Noise removal default:** Production uses `anlmdn_production_current`: `anlmdn` runs at the source sample rate with `r=0.0020` (`r_min`) and `m=3` (`m_strict`), followed by `compand` for residual suppression when a noise profile is available. No sample-rate cap or exit restore - downstream filters (gate, LA-2A, de-esser, analysis) operate at the source rate throughout. The matrix spike at `.bench/anlmdn-matrix-spike` validated this path against the previous 32 kHz cap default (`r=0.0045`, `m=11`) at ~35 % faster Pass 2 with metric-equivalent quality. In benchmark context, refer to the 0.3.1 historical path as `anlmdn_legacy_default`.
 
 **Adeclick default:** Production uses `adeclick=t=2.0:w=55:o=50:m=s` (spline interpolation, halved overlap vs prior default) for ~75% Pass 4 runtime reduction at metric-parity quality; the gentle limiter attack keeps source clicks below the relaxed threshold. In benchmark context, refer to the production path as `adeclick_current_t_2_0_w_55_o_50_m_s`. No legacy variant is retained in the matrix.
 

README.md

@@ -30,7 +30,7 @@ Filter chain inspired by studio legends, tuned to your specific audio:
 | Filter | Hardware Inspiration | What It Does |
 |--------|---------------------|--------------|
 | **Highpass** | Drawmer DS201 | Removes subsonic rumble (60-120 Hz, adaptive to spectral content) |
-| **Noise reduction** | Non-Local Means | Adaptive `anlmdn` denoiser using the production `anlmdn_sr_32000_best_r` path: 32 kHz before `anlmdn`, `r=0.0045`, then compand residual suppression when a noise profile is available |
+| **Noise reduction** | Non-Local Means | Adaptive `anlmdn` denoiser at the source sample rate (`r=0.0020`, `m=3`) followed by compand residual suppression when a noise profile is available |
 | **Gate** | DS201 expander | Soft expansion for natural inter-phrase cleanup; breath reduction option positions threshold between noise floor and quiet speech level |
 | **Compressor** | Teletronix LA-2A | Programme-dependent optical compression; ratio and release adapt to kurtosis and flux. High-crest override pushes ratio, threshold, release, and knee when predicted limiter ceiling deficit is positive |
 | **De-esser** | — | Adaptive intensity (0.0-0.6) based on spectral centroid and rolloff |
@@ -210,7 +210,7 @@ Record → Process → Edit → Finalise
   └─ Each presenter records separately, exports FLAC
 ```
 
-**Include 10-15 seconds of silence somewhere in your recording.** Just sit quietly and let the room breathe - at the start, between sections, or at the end. Jivetalking scans the entire file to find the cleanest quiet section for building a noise profile, which drives the adaptive noise reduction in Pass 2. Without a clean quiet section, the NR compander is disabled entirely and the 32 kHz `anlmdn` path still runs.
+**Include 10-15 seconds of silence somewhere in your recording.** Just sit quietly and let the room breathe - at the start, between sections, or at the end. Jivetalking scans the entire file to find the cleanest quiet section for building a noise profile, which drives the adaptive noise reduction in Pass 2. Without a clean quiet section, the NR compander is disabled entirely and the source-rate `anlmdn` path still runs.
 
 ---
 

docs/Levelator-Comparison-And-Gap-Analysis.md

@@ -102,7 +102,7 @@ downmix → ds201_highpass → ds201_lowpass → noiseremove → ds201_gate →
 |--------|---------------------|-------|
 | **DS201 Highpass** | Frequency (60-120Hz), poles, mix | Spectral centroid, spectral decrease, noise floor |
 | **DS201 Lowpass** | Cutoff frequency, enable/disable | Content type detection (speech/music/mixed), rolloff, ZCR |
-| **NoiseRemove** | Compand threshold, expansion depth (disabled when no noise profile) | Measured noise floor + 5 dB, noise severity; compand requires an elected silence region; production `anlmdn` uses the `anlmdn_sr_32000_best_r` path |
+| **NoiseRemove** | Compand threshold, expansion depth (disabled when no noise profile) | Measured noise floor + 5 dB, noise severity; compand requires an elected silence region; production `anlmdn` runs at the source sample rate with `r=0.0020` and `m=3` |
 | **DS201 Gate** | Threshold, ratio, attack, release, range, knee | LRA, noise floor, quiet speech estimate, spectral flux, entropy |
 | **LA-2A Compressor** | Threshold, ratio, attack, release, knee, mix | Kurtosis, flux, dynamic range, spectral centroid |
 | **De-esser** | Intensity (0.0-0.6) | Spectral centroid + rolloff |
@@ -143,7 +143,7 @@ Jivetalking employs speech profile extraction for adaptive tuning:
 | **Look-ahead Capability** | Yes—infinite look-ahead via multiple passes | Yes—infinite look-ahead via Pass 1 analysis |
 | **Target Loudness Standard** | -18 dB RMS (custom RMS calculation) | -16 LUFS |
 | **Silence Detection** | Fixed: 50ms subsegments > -44 dB | Adaptive: spectral analysis + room tone scoring |
-| **Noise Reduction** | None | `anlmdn` (Non-Local Means, 32 kHz pre-denoise path, `r=0.0045`) + compand |
+| **Noise Reduction** | None | `anlmdn` (Non-Local Means, source-rate denoising at `r=0.0020`, `m=3`) + compand |
 | **Dynamics Processing** | Implicit in leveling algorithm | Explicit LA-2A-style compressor + CBS Volumax limiter |
 | **Gating/Expansion** | None | DS201-inspired soft expander (2:1-4:1 ratio) |
 | **Highpass Filtering** | None | Adaptive 60-120Hz with warm voice protection |
@@ -220,7 +220,7 @@ Jivetalking employs speech profile extraction for adaptive tuning:
 
 ### Capabilities Jivetalking Has That Levelator Lacked
 
-1. **Noise Reduction:** Non-Local Means denoising (`anlmdn`) always active with the production `anlmdn_sr_32000_best_r` path: 32 kHz before `anlmdn`, `r=0.0045`, then restored to the standard processing/output rate. Adaptive compand applies when a silence region is elected as the noise profile
+1. **Noise Reduction:** Non-Local Means denoising (`anlmdn`) always active, running at the source sample rate with a small research radius (`r=0.0020`) and a tight LUT decay (`m=3`) for sharp rejection of distant patches. Adaptive compand applies when a silence region is elected as the noise profile
 2. **Gating:** Soft expander for inter-speech cleanup
 3. **True Peak Limiting:** Prevents inter-sample peaks
 4. **De-essing:** Automatic sibilance control
@@ -419,5 +419,5 @@ Levelator created its own RMS standard because no spoken-word standard existed.
 
 ---
 
-*Report compiled: February 2026*
+*Report compiled: February 2026 (noise-removal section updated May 2026)*
 *Jivetalking version analyzed: Development branch (AGENTS.md dated prior to February 2026)*

internal/logging/report.go

@@ -688,10 +688,7 @@ func formatNoiseRemoveFilter(f *os.File, cfg *processor.FilterChainConfig, m *pr
 	// Header: filter name and algorithm
 	fmt.Fprintf(f, "%snoiseremove: anlmdn + compand (Non-Local Means denoiser)\n", prefix)
 
-	// anlmdn parameters (fixed from spike validation)
-	if cfg.NoiseRemovePreSampleRate > 0 {
-		fmt.Fprintf(f, "        pre-anlmdn sample rate: %d Hz\n", cfg.NoiseRemovePreSampleRate)
-	}
+	// anlmdn parameters (matrix spike defaults: r_min + m_strict at source rate)
 	fmt.Fprintf(f, "        anlmdn: s=%.5f, p=%.4fs, r=%.4fs, m=%.0f\n",
 		cfg.NoiseRemoveStrength,
 		cfg.NoiseRemovePatchSec,

internal/processor/anlmdn_benchmark_test.go

@@ -36,11 +36,10 @@ type anlmdnBenchmarkParams struct {
 }
 
 type anlmdnBenchmarkVariant struct {
-	Name                string
-	ParameterIntent     string
-	ValidationPriority  string
-	PreAnlmdnSampleRate int
-	Params              anlmdnBenchmarkParams
+	Name               string
+	ParameterIntent    string
+	ValidationPriority string
+	Params             anlmdnBenchmarkParams
 }
 
 func anlmdnBenchmarkVariants() []anlmdnBenchmarkVariant {
@@ -60,7 +59,7 @@ func anlmdnBenchmarkVariants() []anlmdnBenchmarkVariant {
 	return []anlmdnBenchmarkVariant{
 		{
 			Name:               "anlmdn_legacy_default",
-			ParameterIntent:    "Legacy production baseline before the 32 kHz lower-r default.",
+			ParameterIntent:    "0.3.1 historical reference: source-rate anlmdn with r=0.0058, m=11.",
 			ValidationPriority: "baseline",
 			Params:             legacyDefault,
 		},
@@ -109,18 +108,10 @@ func anlmdnBenchmarkVariants() []anlmdnBenchmarkVariant {
 			},
 		},
 		{
-			Name:                "anlmdn_sr_32000",
-			ParameterIntent:     "32 kHz pre-anlmdn sample-rate cap with legacy anlmdn parameters.",
-			ValidationPriority:  "tier2-sample-rate-baseline-r",
-			PreAnlmdnSampleRate: noiseRemoveProductionPreSampleRate,
-			Params:              legacyDefault,
-		},
-		{
-			Name:                "anlmdn_sr_32000_best_r",
-			ParameterIntent:     "Production default: 32 kHz pre-anlmdn sample-rate cap with the selected lower-r candidate.",
-			ValidationPriority:  "production-default",
-			PreAnlmdnSampleRate: noiseRemoveProductionPreSampleRate,
-			Params:              productionDefault,
+			Name:               "anlmdn_production_current",
+			ParameterIntent:    "Production default: r_min (r=0.0020) with m_strict (m=3) at source rate.",
+			ValidationPriority: "production-default",
+			Params:             productionDefault,
 		},
 	}
 }
@@ -134,7 +125,6 @@ func buildAnlmdnBenchmarkVariantConfig(base *FilterChainConfig, variant anlmdnBe
 	config.Pass = PassProcessing
 	config.FilterOrder = Pass2FilterOrder
 	config.NoiseRemoveEnabled = true
-	config.NoiseRemovePreSampleRate = variant.PreAnlmdnSampleRate
 	config.NoiseRemoveStrength = variant.Params.Strength
 	config.NoiseRemovePatchSec = variant.Params.PatchSec
 	config.NoiseRemoveResearchSec = variant.Params.ResearchSec
@@ -201,7 +191,6 @@ type anlmdnBenchmarkMetricsSnapshot struct {
 	VariantName                 string                               `json:"variant_name"`
 	ParameterIntent             string                               `json:"parameter_intent"`
 	ValidationPriority          string                               `json:"validation_priority"`
-	PreAnlmdnSampleRate         int                                  `json:"pre_anlmdn_sample_rate,omitempty"`
 	FilterSpec                  string                               `json:"filter_spec"`
 	Pass2RuntimeMS              float64                              `json:"pass2_runtime_ms"`
 	FinalLUFS                   float64                              `json:"final_lufs"`
@@ -442,7 +431,6 @@ func buildAnlmdnBenchmarkMetricsSnapshot(
 		VariantName:                 variantSpec.Variant.Name,
 		ParameterIntent:             variantSpec.Variant.ParameterIntent,
 		ValidationPriority:          variantSpec.Variant.ValidationPriority,
-		PreAnlmdnSampleRate:         variantSpec.Variant.PreAnlmdnSampleRate,
 		FilterSpec:                  variantSpec.Spec,
 		Pass2RuntimeMS:              float64(pass2Runtime.Microseconds()) / 1000.0,
 		FinalLUFS:                   normResult.OutputLUFS,
@@ -822,8 +810,7 @@ func TestAnlmdnBenchmarkVariantManifest(t *testing.T) {
 		"anlmdn_r_4_5",
 		"anlmdn_r_4_0",
 		"anlmdn_r_patch_adjusted",
-		"anlmdn_sr_32000",
-		"anlmdn_sr_32000_best_r",
+		"anlmdn_production_current",
 	}
 
 	if len(variants) != len(expectedNames) {
@@ -847,22 +834,15 @@ func TestAnlmdnBenchmarkVariantManifest(t *testing.T) {
 		}
 	}
 
-	for _, name := range []string{"anlmdn_sr_32000", "anlmdn_sr_32000_best_r"} {
-		if variantByName[name].PreAnlmdnSampleRate != noiseRemoveProductionPreSampleRate {
-			t.Fatalf("%s PreAnlmdnSampleRate = %d, want %d",
-				name, variantByName[name].PreAnlmdnSampleRate, noiseRemoveProductionPreSampleRate)
-		}
-	}
-	for _, name := range []string{"anlmdn_legacy_default", "anlmdn_r_5_0", "anlmdn_r_4_5", "anlmdn_r_4_0", "anlmdn_r_patch_adjusted"} {
-		if variantByName[name].PreAnlmdnSampleRate != 0 {
-			t.Fatalf("%s should not use a pre-anlmdn sample-rate cap", name)
-		}
-	}
-
-	if got := variantByName["anlmdn_sr_32000_best_r"].Params.ResearchSec; got != noiseRemoveProductionResearchSec {
-		t.Fatalf("anlmdn_sr_32000_best_r research radius = %.4f, want production default %.4f",
+	productionVariant := variantByName["anlmdn_production_current"]
+	if got := productionVariant.Params.ResearchSec; got != noiseRemoveProductionResearchSec {
+		t.Fatalf("anlmdn_production_current research radius = %.4f, want production default %.4f",
 			got, noiseRemoveProductionResearchSec)
 	}
+	if got := productionVariant.Params.Smooth; got != noiseRemoveProductionSmooth {
+		t.Fatalf("anlmdn_production_current smooth = %.0f, want production default %.0f",
+			got, noiseRemoveProductionSmooth)
+	}
 }
 
 func TestAnlmdnBenchmarkParameterOnlySpecs(t *testing.T) {
@@ -879,6 +859,7 @@ func TestAnlmdnBenchmarkParameterOnlySpecs(t *testing.T) {
 		{name: "anlmdn_r_4_5", wantSpec: "anlmdn=s=0.00001:p=0.0060:r=0.0045:m=11"},
 		{name: "anlmdn_r_4_0", wantSpec: "anlmdn=s=0.00001:p=0.0060:r=0.0040:m=11"},
 		{name: "anlmdn_r_patch_adjusted", wantSpec: "anlmdn=s=0.00001:p=0.0050:r=0.0045:m=11"},
+		{name: "anlmdn_production_current", wantSpec: "anlmdn=s=0.00001:p=0.0060:r=0.0020:m=3"},
 	}
 
 	for _, tt := range tests {
@@ -910,50 +891,6 @@ func TestAnlmdnBenchmarkParameterOnlySpecs(t *testing.T) {
 	assertBaseLegacyAnlmdnConfigUnchanged(t, base)
 }
 
-func TestAnlmdnBenchmarkPreSampleRateSpecs(t *testing.T) {
-	base := newAnlmdnBenchmarkTestConfig()
-
-	tests := []struct {
-		name     string
-		wantSpec string
-	}{
-		{name: "anlmdn_sr_32000", wantSpec: "anlmdn=s=0.00001:p=0.0060:r=0.0058:m=11"},
-		{name: "anlmdn_sr_32000_best_r", wantSpec: "anlmdn=s=0.00001:p=0.0060:r=0.0045:m=11"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			variant := findAnlmdnBenchmarkVariant(t, tt.name)
-			spec := buildAnlmdnBenchmarkVariantSpec(base, variant)
-
-			assertFullbenchSpecContains(t, spec, []string{
-				"aformat=sample_rates=32000:channel_layouts=mono:sample_fmts=fltp",
-				tt.wantSpec,
-				"anlmdn=",
-				"compand=",
-				"aformat=sample_rates=44100:channel_layouts=mono:sample_fmts=s16",
-				"asetnsamples=n=4096",
-			})
-			assertFullbenchSpecOrder(t, spec, []string{
-				"aformat=channel_layouts=mono",
-				"highpass=",
-				"lowpass=",
-				"aformat=sample_rates=32000:channel_layouts=mono:sample_fmts=fltp",
-				"anlmdn=",
-				"compand=",
-				"agate=",
-				"acompressor=",
-				"deesser=",
-				"astats=",
-				"aspectralstats=",
-				"ebur128=",
-				"aformat=sample_rates=44100",
-				"asetnsamples=",
-			})
-		})
-	}
-}
-
 func TestAnlmdnBenchmarkVariantSpecsPreservePass2Ordering(t *testing.T) {
 	base := newAnlmdnBenchmarkTestConfig()
 
@@ -967,9 +904,15 @@ func TestAnlmdnBenchmarkVariantSpecsPreservePass2Ordering(t *testing.T) {
 			assertFullbenchSpecContains(t, spec, []string{
 				"anlmdn=",
 				"compand=",
-				"aformat=sample_rates=44100",
+				"aformat=sample_rates=44100:channel_layouts=mono:sample_fmts=s16",
 				"asetnsamples=",
 			})
+			assertFullbenchSpecExcludes(t, spec, []string{
+				// The cap+exit-restore architecture has been removed; no
+				// noise-removal sub-block aformat clauses should appear.
+				"aformat=sample_rates=32000",
+				"aformat=sample_rates=44100:channel_layouts=mono:sample_fmts=fltp",
+			})
 			assertFullbenchSpecOrder(t, spec, []string{
 				"aformat=channel_layouts=mono",
 				"highpass=",
@@ -982,23 +925,19 @@ func TestAnlmdnBenchmarkVariantSpecsPreservePass2Ordering(t *testing.T) {
 				"astats=",
 				"aspectralstats=",
 				"ebur128=",
-				"aformat=sample_rates=44100",
+				"aformat=sample_rates=44100:channel_layouts=mono:sample_fmts=s16",
 				"asetnsamples=",
 			})
 		})
 	}
 }
 
-func TestAnlmdnBenchmarkProductionDefaultsMatchFastVariant(t *testing.T) {
+func TestAnlmdnBenchmarkProductionDefaultsMatchProductionVariant(t *testing.T) {
 	config := DefaultFilterConfig()
 
 	if !config.NoiseRemoveEnabled {
 		t.Fatal("production NoiseRemoveEnabled changed")
 	}
-	if config.NoiseRemovePreSampleRate != noiseRemoveProductionPreSampleRate {
-		t.Fatalf("production NoiseRemovePreSampleRate = %d, want %d",
-			config.NoiseRemovePreSampleRate, noiseRemoveProductionPreSampleRate)
-	}
 	if config.NoiseRemoveStrength != noiseRemoveProductionStrength {
 		t.Fatalf("production NoiseRemoveStrength = %.5f, want %.5f",
 			config.NoiseRemoveStrength, noiseRemoveProductionStrength)
@@ -1016,9 +955,9 @@ func TestAnlmdnBenchmarkProductionDefaultsMatchFastVariant(t *testing.T) {
 			config.NoiseRemoveSmooth, noiseRemoveProductionSmooth)
 	}
 
-	fastVariant := findAnlmdnBenchmarkVariant(t, "anlmdn_sr_32000_best_r")
-	if got, want := buildAnlmdnBenchmarkVariantSpec(config, fastVariant), config.BuildFilterSpec(); got != want {
-		t.Fatalf("production filter spec drifted from anlmdn_sr_32000_best_r\nvariant:    %s\nproduction: %s", got, want)
+	productionVariant := findAnlmdnBenchmarkVariant(t, "anlmdn_production_current")
+	if got, want := buildAnlmdnBenchmarkVariantSpec(config, productionVariant), config.BuildFilterSpec(); got != want {
+		t.Fatalf("production filter spec drifted from anlmdn_production_current\nvariant:    %s\nproduction: %s", got, want)
 	}
 
 	expectedOrder := []FilterID{
@@ -1200,9 +1139,6 @@ func assertBaseLegacyAnlmdnConfigUnchanged(tb testing.TB, config *FilterChainCon
 	if !config.NoiseRemoveEnabled {
 		tb.Fatal("base config NoiseRemoveEnabled changed")
 	}
-	if config.NoiseRemovePreSampleRate != 0 {
-		tb.Fatalf("base NoiseRemovePreSampleRate changed: got %d", config.NoiseRemovePreSampleRate)
-	}
 	if config.NoiseRemoveStrength != noiseRemoveLegacyStrength {
 		tb.Fatalf("base NoiseRemoveStrength changed: got %.5f", config.NoiseRemoveStrength)
 	}