Wire live listen status metadata

cmd/sdrd/helpers.go

@@ -129,14 +129,14 @@ func extractSignalIQBatch(extractMgr *extractionManager, iq []complex64, sampleR
 			isWFM := (sigMHz >= 87.5 && sigMHz <= 108.0) || (sig.Class != nil && (sig.Class.ModType == "WFM" || sig.Class.ModType == "WFM_STEREO"))
 			jobOutRate := decimTarget
 			if isWFM {
-				jobOutRate = 500000
+				jobOutRate = wfmStreamOutRate
 			}
 			// Minimum extraction BW: ensure enough bandwidth for demod features
-			// FM broadcast (87.5-108 MHz) needs >=150kHz for stereo pilot + RDS at 57kHz
+			// FM broadcast (87.5-108 MHz) needs >=250kHz for stereo pilot + RDS at 57kHz
 			// Also widen for any signal classified as WFM (in case of re-extraction)
 			if isWFM {
-				if bw < 250000 {
-					bw = 250000
+				if bw < wfmStreamMinBW {
+					bw = wfmStreamMinBW
 				}
 			} else if bw < 20000 {
 				bw = 20000
@@ -162,12 +162,12 @@ func extractSignalIQBatch(extractMgr *extractionManager, iq []complex64, sampleR
 		offset := sig.CenterHz - centerHz
 		shifted := dsp.FreqShift(iq, sampleRate, offset)
 		bw := sig.BWHz
-		// FM broadcast (87.5-108 MHz) needs >=150kHz for stereo + RDS
+		// FM broadcast (87.5-108 MHz) needs >=250kHz for stereo + RDS
 		sigMHz := sig.CenterHz / 1e6
 		isWFM := (sigMHz >= 87.5 && sigMHz <= 108.0) || (sig.Class != nil && (sig.Class.ModType == "WFM" || sig.Class.ModType == "WFM_STEREO"))
 		if isWFM {
-			if bw < 250000 {
-				bw = 250000
+			if bw < wfmStreamMinBW {
+				bw = wfmStreamMinBW
 			}
 		} else if bw < 20000 {
 			bw = 20000
@@ -225,6 +225,10 @@ type extractionConfig struct {
 }
 
 const streamOverlapLen = 512 // must be >= FIR tap count with margin
+const (
+	wfmStreamOutRate = 500000
+	wfmStreamMinBW   = 250000
+)
 
 // extractForStreaming performs GPU-accelerated extraction with:
 //   - Per-signal phase-continuous FreqShift (via PhaseStart in ExtractJob)
@@ -289,9 +293,9 @@ func extractForStreaming(
 			(sig.Class != nil && (sig.Class.ModType == "WFM" || sig.Class.ModType == "WFM_STEREO"))
 		jobOutRate := decimTarget
 		if isWFM {
-			jobOutRate = 300000
-			if bw < 150000 {
-				bw = 150000
+			jobOutRate = wfmStreamOutRate
+			if bw < wfmStreamMinBW {
+				bw = wfmStreamMinBW
 			}
 		} else if bw < 20000 {
 			bw = 20000
@@ -325,11 +329,14 @@ func extractForStreaming(
 		results, err := runner.ShiftFilterDecimateBatchWithPhase(gpuIQ, jobs)
 		if err == nil && len(results) == len(signals) {
 			for i, res := range results {
-				outRate := decimTarget
+				outRate := res.Rate
+				if outRate <= 0 {
+					outRate = decimTarget
+				}
 				sigMHz := signals[i].CenterHz / 1e6
 				isWFM := (sigMHz >= 87.5 && sigMHz <= 108.0) || (signals[i].Class != nil && (signals[i].Class.ModType == "WFM" || signals[i].Class.ModType == "WFM_STEREO"))
 				if isWFM {
-					outRate = 500000
+					outRate = wfmStreamOutRate
 				}
 				decim := sampleRate / outRate
 				if decim < 1 {
@@ -393,7 +400,7 @@ func extractForStreaming(
 		isWFM := (sigMHz >= 87.5 && sigMHz <= 108.0) || (sig.Class != nil && (sig.Class.ModType == "WFM" || sig.Class.ModType == "WFM_STEREO"))
 		outRate := decimTarget
 		if isWFM {
-			outRate = 500000
+			outRate = wfmStreamOutRate
 		}
 		decim := sampleRate / outRate
 		if decim < 1 {

cmd/sdrd/ws_handlers.go

@@ -164,13 +164,15 @@ func registerWSHandlers(mux *http.ServeMux, h *hub, recMgr *recorder.Manager) {
 
 		// LL-2: Send actual audio info (channels, sample rate from session)
 		info := map[string]any{
-			"type":        "audio_info",
-			"sample_rate": audioInfo.SampleRate,
-			"channels":    audioInfo.Channels,
-			"format":      audioInfo.Format,
-			"demod":       audioInfo.DemodName,
-			"freq":        freq,
-			"mode":        mode,
+			"type":          "audio_info",
+			"sample_rate":   audioInfo.SampleRate,
+			"channels":      audioInfo.Channels,
+			"format":        audioInfo.Format,
+			"demod":         audioInfo.DemodName,
+			"playback_mode": audioInfo.PlaybackMode,
+			"stereo_state":  audioInfo.StereoState,
+			"freq":          freq,
+			"mode":          mode,
 		}
 		if infoBytes, err := json.Marshal(info); err == nil {
 			_ = conn.WriteMessage(websocket.TextMessage, infoBytes)

internal/recorder/streamer.go

@@ -25,14 +25,16 @@ import (
 // ---------------------------------------------------------------------------
 
 type streamSession struct {
-	signalID  int64
-	centerHz  float64
-	bwHz      float64
-	snrDb     float64
-	peakDb    float64
-	class     *classifier.Classification
-	startTime time.Time
-	lastFeed  time.Time
+	signalID     int64
+	centerHz     float64
+	bwHz         float64
+	snrDb        float64
+	peakDb       float64
+	class        *classifier.Classification
+	startTime    time.Time
+	lastFeed     time.Time
+	playbackMode string
+	stereoState  string
 
 	// listenOnly sessions have no WAV file and no disk I/O.
 	// They exist solely to feed audio to live-listen subscribers.
@@ -116,10 +118,12 @@ type audioSub struct {
 // AudioInfo describes the audio format of a live-listen subscription.
 // Sent to the WebSocket client as the first message.
 type AudioInfo struct {
-	SampleRate int    `json:"sample_rate"`
-	Channels   int    `json:"channels"`
-	Format     string `json:"format"` // always "s16le"
-	DemodName  string `json:"demod"`
+	SampleRate   int    `json:"sample_rate"`
+	Channels     int    `json:"channels"`
+	Format       string `json:"format"` // always "s16le"
+	DemodName    string `json:"demod"`
+	PlaybackMode string `json:"playback_mode,omitempty"`
+	StereoState  string `json:"stereo_state,omitempty"`
 }
 
 const (
@@ -437,12 +441,7 @@ func (st *Streamer) attachPendingListeners(sess *streamSession) {
 
 			// Send updated audio_info now that we know the real session params.
 			// Prefix with 0x00 tag byte so ws/audio handler sends as TextMessage.
-			infoJSON, _ := json.Marshal(AudioInfo{
-				SampleRate: sess.sampleRate,
-				Channels:   sess.channels,
-				Format:     "s16le",
-				DemodName:  sess.demodName,
-			})
+			infoJSON, _ := json.Marshal(sess.audioInfo())
 			tagged := make([]byte, 1+len(infoJSON))
 			tagged[0] = 0x00 // tag: audio_info
 			copy(tagged[1:], infoJSON)
@@ -520,12 +519,7 @@ func (st *Streamer) SubscribeAudio(freq float64, bw float64, mode string) (int64
 
 	if bestSess != nil && bestDist < 200000 {
 		bestSess.audioSubs = append(bestSess.audioSubs, audioSub{id: subID, ch: ch})
-		info := AudioInfo{
-			SampleRate: bestSess.sampleRate,
-			Channels:   bestSess.channels,
-			Format:     "s16le",
-			DemodName:  bestSess.demodName,
-		}
+		info := bestSess.audioInfo()
 		log.Printf("STREAM: subscriber %d attached to signal %d (%.1fMHz %s)",
 			subID, bestSess.signalID, bestSess.centerHz/1e6, bestSess.demodName)
 		return subID, ch, info, nil
@@ -538,12 +532,7 @@ func (st *Streamer) SubscribeAudio(freq float64, bw float64, mode string) (int64
 		mode: mode,
 		ch:   ch,
 	}
-	info := AudioInfo{
-		SampleRate: streamAudioRate,
-		Channels:   1,
-		Format:     "s16le",
-		DemodName:  "NFM",
-	}
+	info := defaultAudioInfoForMode(mode)
 	log.Printf("STREAM: subscriber %d pending (freq=%.1fMHz)", subID, freq/1e6)
 	log.Printf("LIVEAUDIO MATCH: subscriber=%d pending req=%.3fMHz bw=%.0f mode=%s", subID, freq/1e6, bw, mode)
 	return subID, ch, info, nil
@@ -664,6 +653,7 @@ func (sess *streamSession) processSnippet(snippet []complex64, snipRate int) ([]
 	// --- Stateful stereo decode with conservative lock/hysteresis ---
 	channels := 1
 	if isWFMStereo {
+		sess.playbackMode = "WFM_STEREO"
 		channels = 2 // keep transport format stable for live WFM_STEREO sessions
 		stereoAudio, locked := sess.stereoDecodeStateful(audio, actualDemodRate)
 		if locked {
@@ -680,8 +670,10 @@ func (sess *streamSession) processSnippet(snippet []complex64, snipRate int) ([]
 			}
 		}
 		if sess.stereoEnabled && len(stereoAudio) > 0 {
+			sess.stereoState = "locked"
 			audio = stereoAudio
 		} else {
+			sess.stereoState = "mono-fallback"
 			dual := make([]float32, len(audio)*2)
 			for i, s := range audio {
 				dual[i*2] = s
@@ -999,6 +991,8 @@ func (st *Streamer) openRecordingSession(sig *detector.Signal, now time.Time) (*
 		return nil, err
 	}
 
+	playbackMode, stereoState := initialPlaybackState(demodName)
+
 	sess := &streamSession{
 		signalID:     sig.ID,
 		centerHz:     sig.CenterHz,
@@ -1014,6 +1008,8 @@ func (st *Streamer) openRecordingSession(sig *detector.Signal, now time.Time) (*
 		sampleRate:   streamAudioRate,
 		channels:     channels,
 		demodName:    demodName,
+		playbackMode: playbackMode,
+		stereoState:  stereoState,
 		deemphasisUs: st.policy.DeemphasisUs,
 	}
 
@@ -1039,6 +1035,7 @@ func (st *Streamer) openListenSession(sig *detector.Signal, now time.Time) *stre
 			}
 		}
 	}
+	playbackMode, stereoState := initialPlaybackState(demodName)
 
 	sess := &streamSession{
 		signalID:     sig.ID,
@@ -1053,6 +1050,8 @@ func (st *Streamer) openListenSession(sig *detector.Signal, now time.Time) *stre
 		sampleRate:   streamAudioRate,
 		channels:     channels,
 		demodName:    demodName,
+		playbackMode: playbackMode,
+		stereoState:  stereoState,
 		deemphasisUs: st.policy.DeemphasisUs,
 	}
 
@@ -1077,6 +1076,48 @@ func resolveDemod(sig *detector.Signal) (string, int) {
 	return demodName, channels
 }
 
+func initialPlaybackState(demodName string) (string, string) {
+	playbackMode := demodName
+	stereoState := "mono"
+	if demodName == "WFM_STEREO" {
+		stereoState = "searching"
+	}
+	return playbackMode, stereoState
+}
+
+func (sess *streamSession) audioInfo() AudioInfo {
+	return AudioInfo{
+		SampleRate:   sess.sampleRate,
+		Channels:     sess.channels,
+		Format:       "s16le",
+		DemodName:    sess.demodName,
+		PlaybackMode: sess.playbackMode,
+		StereoState:  sess.stereoState,
+	}
+}
+
+func defaultAudioInfoForMode(mode string) AudioInfo {
+	demodName := "NFM"
+	if requested := normalizeRequestedMode(mode); requested != "" {
+		demodName = requested
+	}
+	channels := 1
+	if demodName == "WFM_STEREO" {
+		channels = 2
+	} else if d := demod.Get(demodName); d != nil {
+		channels = d.Channels()
+	}
+	playbackMode, stereoState := initialPlaybackState(demodName)
+	return AudioInfo{
+		SampleRate:   streamAudioRate,
+		Channels:     channels,
+		Format:       "s16le",
+		DemodName:    demodName,
+		PlaybackMode: playbackMode,
+		StereoState:  stereoState,
+	}
+}
+
 func normalizeRequestedMode(mode string) string {
 	switch strings.ToUpper(strings.TrimSpace(mode)) {
 	case "", "AUTO":

web/app.js

@@ -124,12 +124,18 @@ const presetButtons = Array.from(document.querySelectorAll('.preset-btn'));
 const liveListenBtn = qs('liveListenBtn');
 const listenSecondsInput = qs('listenSeconds');
 const listenModeSelect = qs('listenMode');
+const listenMetaDemod = qs('listenMetaDemod');
+const listenMetaPlayback = qs('listenMetaPlayback');
+const listenMetaStereo = qs('listenMetaStereo');
+const listenMetaRate = qs('listenMetaRate');
+const listenMetaChannels = qs('listenMetaChannels');
 
 let latest = null;
 let currentConfig = null;
 let liveAudio = null;
 let liveListenWS = null; // WebSocket-based live listen
 let liveListenTarget = null; // { freq, bw, mode }
+let liveListenInfo = null;
 let stats = { buffer_samples: 0, dropped: 0, resets: 0, last_sample_ago_ms: -1 };
 let refinementInfo = {};
 let decisionIndex = new Map();
@@ -165,9 +171,12 @@ class LiveListenWS {
         // audio_info JSON message (initial or updated when session attached)
         try {
           const info = JSON.parse(ev.data);
-          if (info.sample_rate || info.channels) {
-            const newRate = info.sample_rate || 48000;
-            const newCh = info.channels || 1;
+          handleLiveListenAudioInfo(info);
+          const hasRate = Number.isFinite(info.sample_rate) && info.sample_rate > 0;
+          const hasCh = Number.isFinite(info.channels) && info.channels > 0;
+          if (hasRate || hasCh) {
+            const newRate = hasRate ? info.sample_rate : this.sampleRate;
+            const newCh = hasCh ? info.channels : this.channels;
             // If channels or rate changed, reinit AudioContext
             if (newRate !== this.sampleRate || newCh !== this.channels) {
               this.sampleRate = newRate;
@@ -279,6 +288,61 @@ class LiveListenWS {
   }
 }
 
+const liveListenDefaults = {
+  demod: '-',
+  playback_mode: 'Inactive',
+  stereo_state: '-',
+  sample_rate: null,
+  channels: null
+};
+
+function formatListenMetaValue(value, fallback = '-') {
+  if (value === undefined || value === null || value === '') return fallback;
+  return String(value);
+}
+
+function renderLiveListenMeta(info) {
+  if (!listenMetaDemod) return;
+  const demod = formatListenMetaValue(info?.demod);
+  const playback = formatListenMetaValue(info?.playback_mode, 'Inactive');
+  const stereo = formatListenMetaValue(info?.stereo_state);
+  const sampleRate = Number.isFinite(info?.sample_rate) && info.sample_rate > 0
+    ? fmtHz(info.sample_rate)
+    : '-';
+  const channels = Number.isFinite(info?.channels) && info.channels > 0
+    ? String(info.channels)
+    : '-';
+
+  listenMetaDemod.textContent = demod;
+  listenMetaPlayback.textContent = playback;
+  listenMetaStereo.textContent = stereo;
+  listenMetaRate.textContent = sampleRate;
+  listenMetaChannels.textContent = channels;
+}
+
+function resetLiveListenMeta() {
+  liveListenInfo = { ...liveListenDefaults };
+  renderLiveListenMeta(liveListenInfo);
+}
+
+function updateLiveListenMeta(partial) {
+  liveListenInfo = { ...(liveListenInfo || liveListenDefaults), ...partial };
+  renderLiveListenMeta(liveListenInfo);
+}
+
+function handleLiveListenAudioInfo(info) {
+  if (!info || typeof info !== 'object') return;
+  const partial = {};
+  if (info.demod) partial.demod = info.demod;
+  if (info.playback_mode) partial.playback_mode = info.playback_mode;
+  if (info.stereo_state) partial.stereo_state = info.stereo_state;
+  if (Number.isFinite(info.sample_rate)) partial.sample_rate = info.sample_rate;
+  if (Number.isFinite(info.channels)) partial.channels = info.channels;
+  if (Object.keys(partial).length > 0) {
+    updateLiveListenMeta(partial);
+  }
+}
+
 function resolveListenMode(detectedMode) {
   const manual = listenModeSelect?.value || '';
   if (manual) return manual;
@@ -304,6 +368,7 @@ function stopLiveListen() {
   }
   liveListenTarget = null;
   setLiveListenUI(false);
+  resetLiveListenMeta();
 }
 
 function startLiveListen(freq, bw, detectedMode) {
@@ -328,9 +393,19 @@ function startLiveListen(freq, bw, detectedMode) {
     liveListenWS = null;
     liveListenTarget = null;
     setLiveListenUI(false);
+    resetLiveListenMeta();
   });
   liveListenWS.start();
   setLiveListenUI(true);
+
+  const startingInfo = {
+    demod: mode || '-',
+    playback_mode: 'Starting',
+    stereo_state: mode === 'WFM_STEREO' ? 'searching' : 'mono',
+    sample_rate: 48000,
+    channels: mode === 'WFM_STEREO' ? 2 : 1
+  };
+  updateLiveListenMeta(startingInfo);
 }
 
 function matchesListenTarget(signal) {
@@ -2292,6 +2367,7 @@ window.addEventListener('keydown', (ev) => {
 });
 
 loadConfig();
+resetLiveListenMeta();
 loadStats();
 loadGPU();
 loadRefinement();

web/index.html

@@ -289,6 +289,14 @@
               </label>
             </div>
             <button class="act-btn" id="liveListenBtn" type="button">Live Listen</button>
+            <div class="listen-meta" id="listenMeta">
+              <div class="listen-meta__title">Live listen status</div>
+              <div class="listen-meta__row"><span>Demod</span><span id="listenMetaDemod">-</span></div>
+              <div class="listen-meta__row"><span>Playback</span><span id="listenMetaPlayback">-</span></div>
+              <div class="listen-meta__row"><span>Stereo</span><span id="listenMetaStereo">-</span></div>
+              <div class="listen-meta__row"><span>Sample rate</span><span id="listenMetaRate">-</span></div>
+              <div class="listen-meta__row"><span>Channels</span><span id="listenMetaChannels">-</span></div>
+            </div>
           </section>
 
           <!-- ── Events Tab ── -->

web/style.css

@@ -373,6 +373,38 @@ input[type="range"]::-moz-range-thumb {
   background: rgba(15, 25, 40, 0.8); border: 1px solid var(--line);
 }
 
+.listen-meta {
+  margin-top: 8px;
+  padding: 8px 10px;
+  border-radius: var(--r);
+  border: 1px solid var(--line);
+  background: rgba(5, 8, 14, 0.6);
+  display: grid;
+  gap: 4px;
+}
+.listen-meta__title {
+  font-family: var(--mono);
+  font-size: 0.6rem;
+  font-weight: 600;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: var(--text-mute);
+  margin-bottom: 2px;
+}
+.listen-meta__row {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+  font-family: var(--mono);
+  font-size: 0.7rem;
+  color: var(--text-dim);
+}
+.listen-meta__row span:last-child {
+  color: var(--text);
+  font-weight: 600;
+}
+
 /* Health Grid */
 .health-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
 .health-card {