From 41b34d35108756e1ef97d686caddf19af257b72e Mon Sep 17 00:00:00 2001 From: Markus Graf Date: Thu, 26 Mar 2026 12:15:36 +0100 Subject: [PATCH] docs(phase-02): complete phase execution --- .planning/STATE.md | 8 +- .../02-VERIFICATION.md | 157 ++++++++++++++++++ 2 files changed, 161 insertions(+), 4 deletions(-) create mode 100644 .planning/phases/02-audio-synthesis-engine/02-VERIFICATION.md diff --git a/.planning/STATE.md b/.planning/STATE.md index 319375c..370ec19 100644 --- a/.planning/STATE.md +++ b/.planning/STATE.md @@ -2,9 +2,9 @@ gsd_state_version: 1.0 milestone: v1.0 milestone_name: milestone -status: Phase complete — ready for verification +status: Ready to plan stopped_at: "Completed 02-03: MP3 encoder and CLI output flag" -last_updated: "2026-03-26T11:09:30.198Z" +last_updated: "2026-03-26T11:15:26.052Z" progress: total_phases: 4 completed_phases: 2 @@ -23,8 +23,8 @@ See: .planning/PROJECT.md (updated 2026-03-24) ## Current Position -Phase: 02 (audio-synthesis-engine) — EXECUTING -Plan: 3 of 3 +Phase: 3 +Plan: Not started ## Performance Metrics diff --git a/.planning/phases/02-audio-synthesis-engine/02-VERIFICATION.md b/.planning/phases/02-audio-synthesis-engine/02-VERIFICATION.md new file mode 100644 index 0000000..9e092b1 --- /dev/null +++ b/.planning/phases/02-audio-synthesis-engine/02-VERIFICATION.md @@ -0,0 +1,157 @@ +--- +phase: 02-audio-synthesis-engine +verified: 2026-03-26T00:00:00Z +status: passed +score: 9/9 must-haves verified +re_verification: false +--- + +# Phase 2: Audio Synthesis Engine — Verification Report + +**Phase Goal:** Synthesize audio from classified traffic — oscillator bank, mixer, MP3 encoder +**Verified:** 2026-03-26 +**Status:** PASSED +**Re-verification:** No — initial verification + +--- + +## Goal Achievement + +### Observable Truths + +All must-haves drawn from PLAN frontmatter across all three plans (02-01, 02-02, 02-03). + +| # | Truth | Status | Evidence | +|---|-------|--------|----------| +| 1 | Each of 11 traffic classes has a unique frequency, harmonic profile, and pan position defined | VERIFIED | `ClassFreqConfigs` in synth/config.go lines 30-44; all 11 classes present, frequencies 65-780 Hz; `TestFrequenciesUnique` + `TestAllClassesHaveConfig` pass | +| 2 | Phase-accumulator oscillator produces non-zero PCM samples with harmonics | VERIFIED | `Oscillator.Advance()` in synth/oscillator.go sums weighted sine partials; `TestOscillatorAdvance` + `TestOscillatorDistinctFreqs` pass | +| 3 | EMA amplitude smoothing moves current amplitude toward target over time | VERIFIED | `Layer.AdvanceSample()` in synth/layer.go applies `currentAmp += alpha*(target-current)`; `TestEMAAmplitudeRise` + `TestEMAAmplitudeDecay` pass | +| 4 | Whisper floor prevents amplitude from reaching zero once a class has been seen | VERIFIED | `UpdateTarget` in synth/layer.go line 46 enforces `whisper + (1.0-whisper)*normalizedRate`; `TestWhisperFloor` pass | +| 5 | go-lame v0.0.9 is in go.mod and CGo build succeeds | VERIFIED | go.mod contains `github.com/sjzar/go-lame v0.0.9` as direct dependency; `CGO_ENABLED=1 go build ./...` exits 0 | +| 6 | OscillatorBank updates all 11 layers from a WindowSnapshot and renders stereo PCM frames | VERIFIED | `OscillatorBank.RenderWindow` in synth/bank.go; `TestNewBankHas11Layers` + `TestRenderWindowOutputLength` + `TestRenderWindowNonZeroWithTraffic` pass | +| 7 | Mixer sums 11 layers with fixed 1/11 gain per layer — peak sum never exceeds 1.0 | VERIFIED | `GainPerLayer` applied in bank.go lines 52-53; `TestMixerNoClip` verifies over 10 windows | +| 8 | Stereo panning uses constant-power pan law producing distinct L/R values for non-center sources | VERIFIED | `PanGains` in synth/mixer.go uses `cos/sin` mapping; `TestPanGainsPowerPreserved` + `TestStereoPan` pass | +| 9 | Synthetic WindowSnapshots produce a valid MP3 file that passes ffprobe validation | VERIFIED | `TestMP3Valid` and `TestEncodeMP3DirectBytes` in encode/mp3_test.go both pass with ffprobe validation | +| 10 | Zero-packet input produces a clear error message and no file on disk | VERIFIED | `if totalPackets == 0` guard in encode/mp3.go line 52 before `os.Create`; `TestZeroPacketError` passes confirming no file created | +| 11 | User can specify -o flag for output path; default includes timestamp | VERIFIED | `StringVarP(&outputPath, "output", "o", ...)` in main.go line 38; `netsynth-%s.mp3` timestamp default line 53; `--help` output confirms flag | +| 12 | MP3 is encoded at 44100 Hz, 128 kbps, stereo via go-lame | VERIFIED | encode/mp3.go: `SetInSamplerate(44100)`, `SetBitrate(128)`, `SetNumChannels(2)`; ffprobe validates output | + +**Score:** 12/12 truths verified (9 distinct must_haves across plans, all with sub-components verified) + +--- + +### Required Artifacts + +| Artifact | Provides | Lines | Status | Details | +|----------|----------|-------|--------|---------| +| `synth/config.go` | FreqConfig, HarmonicDef types; ClassFreqConfigs table for 11 classes | 44 | VERIFIED | Contains `ClassFreqConfigs`, `WhisperFloor=0.03`, `SampleRate=44100`, `GainPerLayer` | +| `synth/oscillator.go` | Phase-accumulator oscillator with Advance method | 38 | VERIFIED | Contains `func (o *Oscillator) Advance(harmonics []HarmonicDef) float64`; uses subtraction wrap not math.Mod | +| `synth/layer.go` | Layer struct with EMA amplitude, whisper floor, target updates | 70 | VERIFIED | Contains `UpdateTarget`, `AdvanceSample`, `l.whisper + (1.0-l.whisper)*normalizedRate` | +| `synth/config_test.go` | Config table tests | 50 | VERIFIED | Contains `TestAllClassesHaveConfig`, `TestFrequenciesInRange`, `TestFrequenciesUnique`, `TestHarmonicsNonEmpty`, `TestPanPositionsInRange` | +| `synth/oscillator_test.go` | Oscillator behavioral tests | 59 | VERIFIED | Contains `TestOscillatorAdvance`, `TestOscillatorPhaseWrap`, `TestOscillatorDistinctFreqs` | +| `synth/layer_test.go` | Layer EMA and whisper floor tests | 88 | VERIFIED | Contains `TestEMAAmplitudeRise`, `TestEMAAmplitudeDecay`, `TestWhisperFloor`, `TestWhisperFloorNotSeenIsZero` | +| `synth/mixer.go` | panGains constant-power function; float64-to-int16 conversion | 40 | VERIFIED | Contains `func PanGains`, `func StereoFramesToInt16Bytes`, `math.Cos(angle), math.Sin(angle)`, `func clamp` | +| `synth/mixer_test.go` | Pan law and PCM conversion tests | 96 | VERIFIED | Contains `TestPanGainsCenter`, `TestStereoFramesToInt16Bytes`, `TestClampPreventsOverflow` | +| `synth/bank.go` | OscillatorBank with NewBank, RenderWindow methods | 58 | VERIFIED | Contains `func NewBank`, `func (b *OscillatorBank) RenderWindow`, `GainPerLayer`, imports classify | +| `synth/bank_test.go` | Bank rendering and mixing tests | 160 | VERIFIED | Contains `TestMixerNoClip`, `TestStereoPan`, `TestRenderWindowOutputLength`, `TestNewBankHas11Layers` | +| `encode/mp3.go` | EncodeMP3 function and RunSynthesis orchestrator | 66 | VERIFIED | Contains `func EncodeMP3`, `func RunSynthesis`, `InitParams()` after Set*, zero-packet guard before `os.Create` | +| `encode/mp3_test.go` | Integration test with ffprobe validation; zero-packet guard test | 182 | VERIFIED | Contains `TestMP3Valid`, `TestZeroPacketError`, `TestEncodeMP3DirectBytes`; uses ffprobe | +| `cmd/netsynth/main.go` | -o flag wiring with timestamp default; snapshot accumulator | 132 | VERIFIED | Contains `outputPath`, `StringVarP`, `netsynth-%s.mp3`, `collectedSnapshots`, `TODO(phase-3)` | + +--- + +### Key Link Verification + +| From | To | Via | Status | Details | +|------|----|-----|--------|---------| +| synth/config.go | classify/types.go | `map[classify.TrafficClass]FreqConfig` | WIRED | Line 30: `var ClassFreqConfigs = map[classify.TrafficClass]FreqConfig{` | +| synth/layer.go | synth/oscillator.go | Layer embeds Oscillator | WIRED | Layer.Osc field is `*Oscillator`; `AdvanceSample` calls `l.Osc.Advance` | +| synth/bank.go | synth/layer.go | Bank holds `map[classify.TrafficClass]*Layer` | WIRED | Line 8: `layers map[classify.TrafficClass]*Layer`; NewBank creates layers | +| synth/bank.go | synth/config.go | Reads ClassFreqConfigs to initialize layers | WIRED | Line 20: `cfg := ClassFreqConfigs[class]` | +| synth/mixer.go | synth/bank.go | StereoFramesToInt16Bytes converts bank output | WIRED | encode/mp3.go line 32 calls `synth.StereoFramesToInt16Bytes(frames)` where frames come from bank.RenderWindow | +| encode/mp3.go | synth/bank.go | RunSynthesis calls bank.RenderWindow per snapshot | WIRED | Lines 57-60: `bank := synth.NewBank(1.0)` then `frames := bank.RenderWindow(snap)` | +| encode/mp3.go | synth/mixer.go | Uses StereoFramesToInt16Bytes for PCM conversion | WIRED | Line 32: `pcmBytes := synth.StereoFramesToInt16Bytes(frames)` | +| cmd/netsynth/main.go | encode/mp3.go | -o flag wired; RunSynthesis integration deferred to Phase 3 | PARTIAL (by design) | `outputPath` defined and populated; `TODO(phase-3)` marks deferred integration point per plan spec | + +Note: The `cmd/netsynth/main.go -> encode/mp3.go` link is PARTIAL by deliberate design. Plan 02-03 explicitly states "Do NOT import the encode package yet — Phase 3 handles that." This is not a gap. + +--- + +### Data-Flow Trace (Level 4) + +The phase produces a file-output pipeline (not a UI component), so data-flow tracing focuses on the end-to-end synthesis chain. + +| Artifact | Data Variable | Source | Produces Real Data | Status | +|----------|---------------|--------|--------------------|--------| +| encode/mp3.go | `allFrames [][2]float64` | `bank.RenderWindow(snap)` for each snapshot | Yes — renders 22050 stereo PCM frames per snapshot via OscillatorBank | FLOWING | +| encode/mp3.go | `pcmBytes []byte` | `synth.StereoFramesToInt16Bytes(allFrames)` | Yes — interleaved int16 LE bytes from float64 frames | FLOWING | +| encode/mp3.go (go-lame) | MP3 file | `wr.Write(pcmBytes)` + `wr.Close()` | Yes — ffprobe validates real MP3 output in tests | FLOWING | +| synth/bank.go | `frames [][2]float64` | 11 layers each calling `AdvanceSample()` with EMA-smoothed oscillators | Yes — non-zero samples when traffic seen; verified by TestRenderWindowNonZeroWithTraffic | FLOWING | + +--- + +### Behavioral Spot-Checks + +| Behavior | Command | Result | Status | +|----------|---------|--------|--------| +| All synth package tests pass | `CGO_ENABLED=1 go test ./synth/... -count=1` | `ok github.com/netsynth/netsynth/synth 0.681s` | PASS | +| All encode package tests pass (including ffprobe MP3 validation) | `CGO_ENABLED=1 go test ./encode/... -count=1` | `ok github.com/netsynth/netsynth/encode 0.307s` | PASS | +| CLI builds and -o flag visible in help | `go run ./cmd/netsynth/ --help \| grep -E "\-o.*output"` | `-o, --output string Output MP3 file path (default: netsynth-.mp3)` | PASS | +| Full CGo build succeeds | `CGO_ENABLED=1 go build ./...` | Exits 0, no errors | PASS | +| Full test suite (all packages) passes | `CGO_ENABLED=1 go test ./...` | All 6 packages pass | PASS | + +29 tests pass across synth and encode packages. + +--- + +### Requirements Coverage + +| Requirement | Source Plan | Description | Status | Evidence | +|-------------|------------|-------------|--------|----------| +| SYNTH-01 | 02-01 | Each traffic class generates a distinct ambient/drone layer (layered sine/harmonic waves) | SATISFIED | `ClassFreqConfigs` has 11 distinct entries; `FreqConfig` carries `BaseHz`, `Harmonics`, `Pan`; oscillator renders additive harmonics via `Advance()` | +| SYNTH-02 | 02-01 | Drone layer amplitudes evolve over time windows based on traffic volume per class | SATISFIED | `Layer.UpdateTarget(count, maxCount)` scales amplitude by normalized rate; EMA smoothing in `AdvanceSample()`; whisper floor maintains presence; `TestEMAAmplitudeRise` + `TestMultipleWindowsEMAConvergence` verify | +| SYNTH-03 | 02-02 | Multiple drone layers are mixed into a single coherent audio stream without distortion | SATISFIED | Fixed `GainPerLayer` (1/11) applied per layer in `RenderWindow`; constant-power panning; `TestMixerNoClip` verifies 11 max-amplitude layers produce no frame with \|L\| or \|R\| > 1.0 | +| OUT-01 | 02-03 | User can specify output file path via -o flag (defaults to `netsynth-.mp3`) | SATISFIED | `StringVarP(&outputPath, "output", "o", ...)` in main.go; timestamp default `netsynth-20060102-150405.mp3`; visible in `--help` | +| OUT-02 | 02-03 | Output is encoded as a valid MP3 file | SATISFIED | `EncodeMP3` uses go-lame at 44100 Hz, 128 kbps, stereo; `TestMP3Valid` + `TestEncodeMP3DirectBytes` use ffprobe to validate MP3 format | +| OUT-03 | 02-03 | Empty captures (zero packets) produce a clear error instead of a corrupt file | SATISFIED | `totalPackets == 0` check in `RunSynthesis` before `os.Create`; returns error "no packets captured: output MP3 not written"; `TestZeroPacketError` verifies no file on disk | + +All 6 requirements declared across the three plans are satisfied. No orphaned requirements found — REQUIREMENTS.md maps all 6 IDs to Phase 2, all 6 are covered. + +--- + +### Anti-Patterns Found + +| File | Line | Pattern | Severity | Impact | +|------|------|---------|----------|--------| +| cmd/netsynth/main.go | 99 | `TODO(phase-3): Pass collectedSnapshots to encode.RunSynthesis(...)` | Info | Expected deferred wiring; plan explicitly defers encode integration to Phase 3. Not a blocker — `outputPath` and `collectedSnapshots` are both populated and ready. | + +No blockers. No stub implementations. No placeholder data. No empty return values in production code paths. + +Note on go.mod: `github.com/sjzar/go-lame` was listed as `// indirect` prior to verification but `encode/mp3.go` imports it directly. Running `go mod tidy` during verification corrected this — the dependency is now properly marked as direct in go.mod. Build and tests were unaffected throughout. + +--- + +### Human Verification Required + +None required. All phase-2 behaviors are verifiable programmatically: + +- Audio quality (timbre, harmonic distinctness) will be evaluable in Phase 3 when live traffic synthesis is complete. Phase 2's contract is correct PCM generation and valid MP3 encoding, both of which are verified via ffprobe. +- The -o flag produces the correct timestamp format; its integration into the live pipeline (Phase 3) is the appropriate point for end-to-end UX testing. + +--- + +### Gaps Summary + +No gaps. All must-haves from the three plans are verified at all levels: + +- Level 1 (exists): All 13 artifact files are present +- Level 2 (substantive): All files contain required functions, patterns, and implementations +- Level 3 (wired): All key links are connected; the one deferred link (main.go -> encode) is intentional per plan spec +- Level 4 (data flowing): The full synthesis pipeline WindowSnapshot -> OscillatorBank -> stereo PCM -> MP3 is traced end-to-end; ffprobe validates real output + +The phase goal is achieved. + +--- + +_Verified: 2026-03-26_ +_Verifier: Claude (gsd-verifier)_