From c75b10c88efa359bc5d3ed08a71312826def1386 Mon Sep 17 00:00:00 2001
From: Jan Svabenik <jan@svabi.ch>
Date: Sun, 22 Mar 2026 23:39:03 +0100
Subject: [PATCH] Normalize broadcast FM signals to WFM_STEREO metadata

---
 cmd/sdrd/pipeline_runtime.go | 21 ++++++++++++++++++---
 internal/pipeline/refiner.go | 20 ++++++++++++++++++--
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/cmd/sdrd/pipeline_runtime.go b/cmd/sdrd/pipeline_runtime.go
index a7d2d41..c5e3c04 100644
--- a/cmd/sdrd/pipeline_runtime.go
+++ b/cmd/sdrd/pipeline_runtime.go
@@ -685,17 +685,32 @@ func (rt *dspRuntime) refineSignals(art *spectrumArtifacts, input pipeline.Refin
 		decision := pipeline.DecideSignalAction(policy, ref.Candidate, cls)
 		decisions = append(decisions, decision)
 		if cls != nil {
+			if cls.ModType == classifier.ClassWFM {
+				cls.ModType = classifier.ClassWFMStereo
+				signals[i].PlaybackMode = string(classifier.ClassWFMStereo)
+				signals[i].DemodName = string(classifier.ClassWFMStereo)
+				signals[i].StereoState = "searching"
+			}
 			pll := classifier.PLLResult{}
 			if i < len(snips) && snips[i] != nil && len(snips[i]) > 256 {
 				pll = classifier.EstimateExactFrequency(snips[i], snipRate, signals[i].CenterHz, cls.ModType)
 				cls.PLL = &pll
 				signals[i].PLL = &pll
-				if cls.ModType == classifier.ClassWFM && pll.Stereo {
-					cls.ModType = classifier.ClassWFMStereo
+				if cls.ModType == classifier.ClassWFMStereo {
+					if pll.Stereo {
+						signals[i].StereoState = "locked"
+					} else if signals[i].StereoState == "" {
+						signals[i].StereoState = "searching"
+					}
+					signals[i].PlaybackMode = string(classifier.ClassWFMStereo)
+					signals[i].DemodName = string(classifier.ClassWFMStereo)
 				}
 			}
-			if (cls.ModType == classifier.ClassWFM || cls.ModType == classifier.ClassWFMStereo) && rec != nil {
+			if cls.ModType == classifier.ClassWFMStereo && rec != nil {
 				rt.updateRDS(art.now, rec, &signals[i], cls)
+				if signals[i].PLL != nil && signals[i].PLL.RDSStation != "" {
+					signals[i].StereoState = "locked"
+				}
 			}
 		}
 	}
diff --git a/internal/pipeline/refiner.go b/internal/pipeline/refiner.go
index ea405f2..e12fe1b 100644
--- a/internal/pipeline/refiner.go
+++ b/internal/pipeline/refiner.go
@@ -36,12 +36,28 @@ func RefineCandidates(candidates []Candidate, windows []RefinementWindow, spectr
 			BWHz:     sig.BWHz,
 		}, spectrum, sampleRate, fftSize, snip, mode)
 		sig.Class = cls
+		if cls != nil && cls.ModType == classifier.ClassWFM {
+			cls.ModType = classifier.ClassWFMStereo
+			sig.PlaybackMode = string(classifier.ClassWFMStereo)
+			sig.DemodName = string(classifier.ClassWFMStereo)
+			if sig.PLL != nil && sig.PLL.Stereo {
+				sig.StereoState = "locked"
+			} else {
+				sig.StereoState = "searching"
+			}
+		}
 		if cls != nil && snip != nil && len(snip) > 256 {
 			pll := classifier.EstimateExactFrequency(snip, snipRate, sig.CenterHz, cls.ModType)
 			cls.PLL = &pll
 			sig.PLL = &pll
-			if cls.ModType == classifier.ClassWFM && pll.Stereo {
-				cls.ModType = classifier.ClassWFMStereo
+			if cls.ModType == classifier.ClassWFMStereo {
+				if pll.Stereo {
+					sig.StereoState = "locked"
+				} else if sig.StereoState == "" {
+					sig.StereoState = "searching"
+				}
+				sig.PlaybackMode = string(classifier.ClassWFMStereo)
+				sig.DemodName = string(classifier.ClassWFMStereo)
 			}
 		}
 		var window RefinementWindow