stt: make the golden tests fail where they used to disappear

The file comment named four regressions caught here. Three were not.
Nothing on this path resamples, because PCMFromWAV refuses anything that
is not already 16 kHz mono s16. Nothing exercises language selection,
because the hint comes out of the manifest already correct. And a bad
model path was the one condition that made the whole test vanish behind
a skip nobody reads. The comment now claims the two things that are
real, an explicitly set MAVEN_WHISPER_MODEL that does not exist is a
failure, and a missing fixture is a failure rather than a skip.

looseWordMatch accepted a different word. Four retained runes of "воды"
is "вод", so whisper hearing "выпил водки" satisfied the ru_fact
keyword, and "dis" let display, distance and discuss all stand in for
"disk". A case ending adds a rune, not a syllable, so the hypothesis is
capped in length as well as matched on prefix.

The spoken text lived in the generator and in the manifest with nothing
tying them together. Editing one left the other describing audio that no
longer existed, and at a flat ceiling of 0.34 over a five-word reference
a one-word drift passed silently. The script reads text out of the
manifest now, and the ceilings are set just above what each case really
measures against ggml-small, with the measurement recorded beside them.

Also: the test carried its own copy of the PCM to float32 conversion, so
a regression in the daemon's copy left the silence-gate assertion green,
and the manifest was validated for keywords but not for text, where an
empty reference makes every hypothesis score a WER of 1.

Found in review of #75.
This commit is contained in:
kami
2026-08-01 14:16:02 +04:00
parent ec5167de3a
commit d68708b5e1
5 changed files with 152 additions and 39 deletions
+7 -2
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@@ -149,8 +149,13 @@ eval-models:
# stt-fixtures — regenerate the golden STT audio in cmd/mavsttd/testdata from
# the piper voices (#288). The committed WAVs are synthesised, never recorded,
# so this is the only way they should ever change. TestGoldenAudioTranscription
# then scores them against ggml-small; it self-skips when the model is absent.
# so this is the only way they should ever change. The spoken text is read out
# of testdata/golden_v1.json, so edit the transcript there and rerun this.
#
# test-stt-golden runs both golden tests: TestGoldenAudioTranscription, which
# scores the fixtures against ggml-small and self-skips when the model is
# absent, and TestGoldenFixturesAreCanonical, which checks the committed audio
# and the manifest with no model at all.
stt-fixtures:
./scripts/gen-stt-fixtures.sh
+86 -18
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@@ -2,10 +2,22 @@ package main
// Golden-audio STT tests (Vikunja #288).
//
// These push real audio through the real whisper.cpp binding, so a bad model
// path, a wrong language hint, a broken resample or a regressed silence gate
// is caught by `make test` rather than by the owner talking to a daemon that
// mishears him.
// These push real audio through the real whisper.cpp binding. What that
// covers, precisely, is two things: the model still transcribes known speech
// well enough for the router to act on it, and the silence gate still lets real
// speech through. A regression in either shows up in `make test` rather than in
// the owner talking to a daemon that mishears him.
//
// It is worth being exact about what is NOT covered, because this comment used
// to claim more. Nothing here resamples: audio.PCMFromWAV refuses anything that
// is not 16 kHz mono s16, the fixtures arrive at 16 kHz from ffmpeg, and there
// is no conversion step between the WAV and whisper_full. Nothing here
// exercises language selection either: the hint comes out of the manifest
// already correct and goes straight into the request, so how mavsttd chooses a
// language is untested. And a wrong model path is not caught when it is the
// default one, because a box without the model skips; an explicitly set
// MAVEN_WHISPER_MODEL that does not exist is a failure, since that is a
// mistake and not an absence.
//
// The fixtures are piper-synthesised, not recorded — see
// scripts/gen-stt-fixtures.sh. Nothing of the owner's voice is committed, and
@@ -47,7 +59,10 @@ type goldenCase struct {
Lang string `json:"lang"`
Text string `json:"text"`
Keywords []string `json:"keywords"`
MaxWER float64 `json:"max_wer"`
// MeasuredWER is what this case scored when the ceiling was last set, so
// a model swap is a diff to a recorded number rather than silence.
MeasuredWER float64 `json:"measured_wer"`
MaxWER float64 `json:"max_wer"`
}
type goldenManifest struct {
@@ -152,6 +167,14 @@ func containsSeq(hyp, want []string) bool {
return false
}
// looseWordMatch reports whether got is want, or an inflection of it.
//
// A shared prefix alone is not enough. "воды" retains three runes, so "водка"
// used to satisfy the ru_fact keyword and the test passed on whisper hearing
// "выпил водки". "disk" retains "dis", which "display", "distance" and
// "discuss" all match. So the hypothesis is also capped in length: a case
// ending adds a rune or two, it does not add a syllable. Short words get no
// slack at all, because there is nothing left of them after a prefix cut.
func looseWordMatch(got, want string) bool {
if got == want {
return true
@@ -166,6 +189,13 @@ func looseWordMatch(got, want string) bool {
if n < 3 || len(g) < n {
return false
}
extra := 2
if len(w) <= 4 {
extra = 0
}
if len(g) > len(w)+extra {
return false
}
return string(g[:n]) == string(w[:n])
}
@@ -176,6 +206,11 @@ func TestGoldenAudioTranscription(t *testing.T) {
model := goldenModelPath()
if _, err := os.Stat(model); err != nil {
// An explicit override that points at nothing is a mistake, not a box
// without the model. Skipping there made a typo look like a pass.
if os.Getenv("MAVEN_WHISPER_MODEL") != "" {
t.Fatalf("MAVEN_WHISPER_MODEL=%s does not exist: %v", model, err)
}
t.Skipf("whisper model %s absent (%v) — set MAVEN_WHISPER_MODEL or see AGENTS.md", model, err)
}
@@ -192,7 +227,9 @@ func TestGoldenAudioTranscription(t *testing.T) {
path := filepath.Join("testdata", c.WAV)
raw, err := os.ReadFile(path)
if err != nil {
t.Skipf("fixture %s absent (%v) — run scripts/gen-stt-fixtures.sh", path, err)
// Not a skip. A fixture the generator failed to write is a
// broken checkout, and skipping made `make test` green on one.
t.Fatalf("fixture %s absent (%v) — run scripts/gen-stt-fixtures.sh", path, err)
}
format, pcm, err := audio.PCMFromWAV(raw)
if err != nil {
@@ -221,9 +258,12 @@ func TestGoldenAudioTranscription(t *testing.T) {
if missing := missingKeywords(c.Keywords, hyp); len(missing) > 0 {
t.Errorf("%s: missing keywords %v in %q", c.WAV, missing, resp.Text)
}
if wer := wordErrorRate(ref, hyp); wer > c.MaxWER {
t.Errorf("%s: WER %.2f > %.2f\n want: %q\n got: %q", c.WAV, wer, c.MaxWER, c.Text, resp.Text)
wer := wordErrorRate(ref, hyp)
if wer > c.MaxWER {
t.Errorf("%s: WER %.2f > %.2f (measured %.2f when the ceiling was set)\n want: %q\n got: %q",
c.WAV, wer, c.MaxWER, c.MeasuredWER, c.Text, resp.Text)
}
t.Logf("%s: WER %.2f (ceiling %.2f, was %.2f)", c.WAV, wer, c.MaxWER, c.MeasuredWER)
})
}
}
@@ -253,27 +293,29 @@ func TestGoldenFixturesAreCanonical(t *testing.T) {
}
// The fixture must clear mavsttd's own silence gate, otherwise the
// model test below would be asserting on a gated empty string.
if reason := gateReason(pcmToF32(pcm), whisperSampleRate, 300, 0.01); reason != "" {
if reason := gateReason(pcmSamples(pcm), whisperSampleRate, 300, 0.01); reason != "" {
t.Errorf("%s: would be gated as %s", path, reason)
}
if len(c.Keywords) == 0 {
t.Errorf("%s: manifest case has no keywords", c.Name)
}
// An empty reference makes wordErrorRate return 1 for every
// hypothesis, so the WER assertion fires with nothing useful to say.
if len(normalizeTranscript(c.Text)) == 0 {
t.Errorf("%s: manifest case has no reference text", c.Name)
}
if c.Lang != "ru" && c.Lang != "en" {
t.Errorf("%s: lang %q is not one of the two languages mavsttd is run with", c.Name, c.Lang)
}
if c.MaxWER <= 0 || c.MaxWER > 1 {
t.Errorf("%s: max_wer %v outside (0,1]", c.Name, c.MaxWER)
}
if c.MeasuredWER > c.MaxWER {
t.Errorf("%s: measured_wer %v is above max_wer %v, so the ceiling was never met", c.Name, c.MeasuredWER, c.MaxWER)
}
}
}
func pcmToF32(b []byte) []float32 {
out := make([]float32, len(b)/2)
for i := range out {
s := int16(b[i*2]) | int16(b[i*2+1])<<8
out[i] = float32(s) / 32768.0
}
return out
}
// --- matcher unit tests (no model, no fixtures) ----------------------------
func TestNormalizeTranscript(t *testing.T) {
@@ -320,4 +362,30 @@ func TestMissingKeywords(t *testing.T) {
if got := missingKeywords([]string{"часть"}, hyp2); len(got) != 1 {
t.Fatalf("missingKeywords = %v, want %q reported missing", got, "часть")
}
// A prefix is not a word. These are different words that share one, and
// each of them used to satisfy the keyword it is paired with.
different := [][2]string{
{"воды", "Я выпил водки."},
{"disk", "check the display"},
{"disk", "we should discuss it"},
{"server", "a serverless function"},
}
for _, d := range different {
if got := missingKeywords([]string{d[0]}, normalizeTranscript(d[1])); len(got) != 1 {
t.Errorf("keyword %q was satisfied by %q", d[0], d[1])
}
}
// And the inflections still pass, which is the whole point of the loose
// match.
same := [][2]string{
{"воды", "выпил воду"},
{"напомни", "напомните мне"},
{"календарю", "по календаре"},
{"restart", "restarted the server"},
}
for _, d := range same {
if got := missingKeywords([]string{d[0]}, normalizeTranscript(d[1])); len(got) != 0 {
t.Errorf("keyword %q was not matched by %q", d[0], d[1])
}
}
}
+10 -5
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@@ -1,5 +1,6 @@
{
"note": "Golden STT fixtures. Audio is piper-synthesised, not recorded — see scripts/gen-stt-fixtures.sh. Regenerate with that script; do not hand-edit `wav`.",
"note": "Golden STT fixtures. Audio is piper-synthesised, not recorded — see scripts/gen-stt-fixtures.sh, which reads `text` from this file and synthesises from it. This is the only source of the spoken words; regenerate with that script and do not hand-edit `wav`.",
"wer_note": "max_wer is set just above what each case actually measures against ggml-small, recorded in `measured_wer` on 2026-08-01. A flat 0.34 over a five-word reference tolerated two wrong words and left most of the range unguarded. A model swap should show up as a diff to these numbers, not as silence: rerun `make test-stt-golden`, read the logged transcript, and move both fields together.",
"cases": [
{
"name": "ru_reminder",
@@ -7,7 +8,8 @@
"lang": "ru",
"text": "напомни мне через час позвонить маме",
"keywords": ["напомни", "час", "позвонить"],
"max_wer": 0.34
"measured_wer": 0.0,
"max_wer": 0.1
},
{
"name": "ru_fact",
@@ -15,7 +17,8 @@
"lang": "ru",
"text": "отметь что я выпил воды",
"keywords": ["отметь", "воды"],
"max_wer": 0.34
"measured_wer": 0.2,
"max_wer": 0.25
},
{
"name": "ru_query",
@@ -23,7 +26,8 @@
"lang": "ru",
"text": "что у меня сегодня по календарю",
"keywords": ["сегодня", "календарю"],
"max_wer": 0.34
"measured_wer": 0.0,
"max_wer": 0.1
},
{
"name": "en_act",
@@ -31,7 +35,8 @@
"lang": "en",
"text": "restart the web server and check the disk space",
"keywords": ["restart", "server", "disk"],
"max_wer": 0.34
"measured_wer": 0.0,
"max_wer": 0.1
}
]
}
+15 -7
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@@ -66,6 +66,19 @@ func gateReason(samples []float32, rate, minMs int, minRMS float64) string {
return ""
}
// pcmSamples converts canonical s16le little-endian PCM to the float32 range
// whisper wants. Shared with the golden tests: they used to carry their own
// copy, so a regression here (a /32767 divisor, a byte order slip) left the
// assertion that the fixtures clear the silence gate green.
func pcmSamples(b []byte) []float32 {
out := make([]float32, len(b)/2)
for i := range out {
s := int16(b[i*2]) | int16(b[i*2+1])<<8
out[i] = float32(s) / 32768.0
}
return out
}
func (h *whisperHandler) Transcribe(ctx context.Context, req worker.TranscribeReq) (worker.TranscribeResp, error) {
if err := ctx.Err(); err != nil {
return worker.TranscribeResp{}, fmt.Errorf("whisper: context done before transcribe: %w", err)
@@ -75,12 +88,7 @@ func (h *whisperHandler) Transcribe(ctx context.Context, req worker.TranscribeRe
return worker.TranscribeResp{}, fmt.Errorf("whisper: empty audio")
}
nSamples := len(a.Bytes) / 2
samples := make([]float32, nSamples)
for i := 0; i < nSamples; i++ {
s := int16(a.Bytes[i*2]) | int16(a.Bytes[i*2+1])<<8
samples[i] = float32(s) / 32768.0
}
samples := pcmSamples(a.Bytes)
// Silence gate: drop non-speech before whisper hallucinates on it.
if reason := gateReason(samples, whisperSampleRate, h.minMs, h.minRMS); reason != "" {
@@ -111,7 +119,7 @@ func (h *whisperHandler) Transcribe(ctx context.Context, req worker.TranscribeRe
ch := make(chan result, 1)
cSamples := (*C.float)(unsafe.Pointer(&samples[0]))
go func() {
ch <- result{code: int(C.whisper_full(h.ctx, params, cSamples, C.int(nSamples)))}
ch <- result{code: int(C.whisper_full(h.ctx, params, cSamples, C.int(len(samples))))}
}()
select {
case r := <-ch:
+34 -7
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@@ -10,6 +10,13 @@
# Usage:
# scripts/gen-stt-fixtures.sh
#
# The spoken text is NOT written here. It is read out of
# cmd/mavsttd/testdata/golden_v1.json, which is the same file the test scores
# against. It used to live in both places, so editing this script and running
# make stt-fixtures left the manifest describing audio that no longer existed —
# and at a WER ceiling of 0.34 over a five-word reference, a one-word drift
# passed silently. Punctuation does not matter: normalizeTranscript strips it.
#
# Voices are picked up from, in order, $PIPER_VOICE_RU / $PIPER_VOICE_EN, then
# the repo's models/tts, then ~/esp-server/voices. The English voice is not
# vendored; if it is missing the English fixture is skipped and the existing
@@ -34,6 +41,26 @@ ru="$(pick_voice "${PIPER_VOICE_RU:-}" "$root/models/tts/ru_RU-irina-medium.onnx
}
en="$(pick_voice "${PIPER_VOICE_EN:-}" "$root/models/tts/en_US-lessac-medium.onnx" "$HOME/esp-server/voices/en_US-lessac-medium.onnx")" || en=""
manifest="$root/cmd/mavsttd/testdata/golden_v1.json"
command -v jq >/dev/null || { echo "jq is required to read $manifest" >&2; exit 1; }
[ -f "$manifest" ] || { echo "missing $manifest" >&2; exit 1; }
# case_text <name> — the reference transcript for one manifest case.
case_text() {
local name="$1" text
text="$(jq -r --arg n "$name" '.cases[] | select(.name==$n) | .text' "$manifest")"
[ -n "$text" ] && [ "$text" != "null" ] || { echo "no case named $name in $manifest" >&2; exit 1; }
printf '%s' "$text"
}
# case_wav <name> — the file name the manifest expects for one case.
case_wav() {
local name="$1" wav
wav="$(jq -r --arg n "$name" '.cases[] | select(.name==$n) | .wav' "$manifest")"
[ -n "$wav" ] && [ "$wav" != "null" ] || { echo "no case named $name in $manifest" >&2; exit 1; }
printf '%s' "$wav"
}
# synth <voice> <out.wav> <text>
# piper emits raw 22050 Hz s16le on stdout; ffmpeg resamples to the canonical
# 16 kHz mono and writes a plain 44-byte-header WAV (-fflags bitexact keeps
@@ -51,15 +78,15 @@ synth() {
echo "wrote $dest ($(stat -c%s "$dest") bytes)"
}
synth "$ru" "$out/ru_reminder.wav" "Напомни мне через час позвонить маме."
synth "$ru" "$out/ru_fact.wav" "Отметь, что я выпил воды."
synth "$ru" "$out/ru_query.wav" "Что у меня сегодня по календарю?"
for name in ru_reminder ru_fact ru_query; do
synth "$ru" "$out/$(case_wav "$name")" "$(case_text "$name")"
done
if [ -n "$en" ]; then
# Keep the English line free of words piper spells out letter by letter —
# "nginx" comes out of lessac as "engine X", which is a TTS artefact and
# would make the fixture assert on the wrong thing.
synth "$en" "$out/en_act.wav" "Restart the web server and check the disk space."
# Keep the English line in the manifest free of words piper spells out
# letter by letter — "nginx" comes out of lessac as "engine X", which is a
# TTS artefact and would make the fixture assert on the wrong thing.
synth "$en" "$out/$(case_wav en_act)" "$(case_text en_act)"
else
echo "no english piper voice found — skipping en_act.wav" >&2
fi