rouggy
d6a2e84eed
The first RX-audio CW decoder decoded poorly on real signals (vs SDC) and was
removed in cafade0. This rebuilds the DSP core from scratch in
internal/cwdecode, keeping v1's good ideas (pitch lock, Flex cw_pitch
targeting, tiered acquisition) and fixing its proven failures:
- Two-way DEBOUNCE (pending-commit ~0.3 dit): v1 rejected short marks but not
short spaces, so a one-hop fade inside a dah shattered it into dits — the
single worst real-signal failure.
- Per-character BATCH dit/dah classification at flush time, using the batch's
own bimodal boundary — the first letter of an over decodes at any speed; the
timing clusters (muDit/muDah) are updated with the same attribution, killing
the classify-then-learn feedback spiral ("all dits at 60 WPM").
- dB-domain envelope with separate floor/peak trackers, hysteresis slicer,
span CAP (30 dB — else quiet backgrounds put the off-threshold in the
analysis-window skirts and letters merge) and window de-bias on durations.
- Double squelch: span >= 6 dB AND peak >= bank-median + 9.5 dB (span alone
cannot reject pure noise).
- Hamming-windowed Goertzel, 16 ms window / 5 ms hop (a 20 ms window left
40 WPM inter-element gaps with no envelope dip).
- Hardened acquisition (overlapping windows made "3 stable hops" meaningless)
plus SUPERVISED RE-LOCK: a clearly stronger tone on another pitch sustained
~1 s takes over — heals noise locks and follows a QSY.
- Gap-fed dit-length tracking (inter-element gaps are timing evidence too).
Proven by a synthetic-signal test suite (all passing): clean 12-40 WPM, three
pitches, added noise, QSB fading 0.35-1.0, 10 ms dropouts inside dahs, QRM in
auto and targeted modes, noise-only squelch, mid-over speed change 25->15 WPM,
and jittered hand keying (+/-20-25%, 3 seeds).
Wiring and UI restored from git (app_cw.go, Ear header button, decoded-text
strip with WPM/pitch/level + pitch lock + click-a-word-to-fill-callsign, Tools
menu entry) — strip strings translated (cwd.* i18n keys, EN/FR) this time.
31 lines
810 B
Go
31 lines
810 B
Go
package cwdecode
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import (
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"fmt"
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"testing"
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)
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// TestDebugTrace prints the element stream for a chosen case — a development
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// aid, not an assertion test. Run with: go test -run TestDebugTrace -v
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func TestDebugTrace(t *testing.T) {
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if testing.Short() {
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t.Skip("debug aid")
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}
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const fs = 16000
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samples := keyMessage("CQ TEST DE F4BPO K", fs, 40, 700, 9000)
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var d *Decoder
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d = New(fs, func(s string) { fmt.Printf("EMIT %q (muDit=%.0f muDah=%.0f)\n", s, d.muDit, d.muDah) }, nil)
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lastMarks := 0
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for i := 0; i < len(samples); i += 256 {
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end := i + 256
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if end > len(samples) {
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end = len(samples)
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}
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d.Process(samples[i:end])
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if d.marksSeen != lastMarks {
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lastMarks = d.marksSeen
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fmt.Printf("mark#%d elems=%v muDit=%.0f muDah=%.0f\n", d.marksSeen, d.elemMs, d.muDit, d.muDah)
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}
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}
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}
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