feat(dsp): spectrogram + AEC measurement toolkit (specview)

Public Access

Add a dependency-free signal-analysis toolkit and a `specview` dev CLI to
evaluate audio (especially echo cancellation) with objective numbers and a
terminal spectrogram instead of ear alone.

- src/dsp/: hand-written radix-2 FFT, Hann window, STFT, seeded test-signal
  generators (sine/log-sweep/white/pink/impulse), metrics (RMS/dBFS/peak/ERLE/
  per-band energy), minimal WAV read+write, and a 24-bit-ANSI half-block
  spectrogram renderer (magma colormap, freq/time axes, dB legend, ASCII
  fallback). Pure layers have no I/O; only `wav` touches the filesystem.
- src/bin/specview.rs: `gen` (conjure a test signal -> WAV), `show` (spectrogram
  + per-band energy summary), `erle` (broadband + per-band echo-return-loss
  between a before/after pair).
- 27 unit tests (FFT correctness, ERLE landmarks, WAV round-trip, render shape).
  Verified end-to-end: log sweep renders as the expected exponential curve;
  a 20 dB-quieter copy reads +20.0 dB ERLE broadband and per band.

Measurement substrate for upcoming AEC refinement (no shipped-path changes).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

This commit is contained in:

mollusk

2026-06-14 02:25:58 -04:00

co-authored by

Claude Opus 4.8

parent d3e831d5e7

commit aa94e861b1

11 changed files with 1314 additions and 0 deletions

									
										Cargo.toml
									
		+4
		
												View File
												
				@@ -15,6 +15,10 @@ path = "src/main.rs"

				name = "test_net"

				path = "src/bin/test_net.rs"

				[[bin]]

				name = "specview"

				path = "src/bin/specview.rs"

				[dependencies]

				anyhow = "1.0.102"

				async-trait = "0.1.89"