From 6676b669930a72aea37a6dfed9664e6a3d2c6f81 Mon Sep 17 00:00:00 2001
From: Stan Grams <sjg@haxx.space>
Date: Sat, 1 Aug 2026 02:07:32 +0200
Subject: [PATCH] [fix](trx-frontend): account for WFM interference in auto
 bandwidth

---
 .../trx-frontend-http/assets/web/app.js       | 33 ++++++++++++++++---
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
index 5d40aeff..b6a0b257 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
@@ -840,6 +840,8 @@ let jogMult = loadSetting("jogMult", 1);      // divisor: 1, 10, 100
 let jogStep = Math.max(Math.round(jogUnit / jogMult), 1);
 let minFreqStepHz = 1;
 let lastModeName = "";
+let lastWfmCci = 0;
+let lastWfmAci = 0;
 const VFO_COLORS = ["var(--accent-green)", "var(--accent-yellow)"];
 function vfoColor(idx) {
   if (idx < VFO_COLORS.length) return VFO_COLORS[idx];
@@ -3293,8 +3295,14 @@ function render(update) {
       wfmStFlagEl.classList.toggle("wfm-st-flag-stereo", detected);
       wfmStFlagEl.classList.toggle("wfm-st-flag-mono", !detected);
     }
-    if (typeof update.filter.wfm_cci === "number") updateIntfBar(wfmCciFillEl, wfmCciValEl, update.filter.wfm_cci);
-    if (typeof update.filter.wfm_aci === "number") updateIntfBar(wfmAciFillEl, wfmAciValEl, update.filter.wfm_aci);
+    if (typeof update.filter.wfm_cci === "number") {
+      lastWfmCci = Math.max(0, Math.min(100, update.filter.wfm_cci));
+      updateIntfBar(wfmCciFillEl, wfmCciValEl, lastWfmCci);
+    }
+    if (typeof update.filter.wfm_aci === "number") {
+      lastWfmAci = Math.max(0, Math.min(100, update.filter.wfm_aci));
+      updateIntfBar(wfmAciFillEl, wfmAciValEl, lastWfmAci);
+    }
     if (samStereoWidthEl && typeof update.filter.sam_stereo_width === "number") {
       samStereoWidthEl.value = String(Math.round(update.filter.sam_stereo_width * 100));
     }
@@ -4348,7 +4356,7 @@ async function applyBandwidthFromInput() {
   } catch (_) {}
 }
 
-function estimateOccupiedBandwidth(data, centerHz) {
+function estimateOccupiedBandwidth(data, centerHz, interference = {}) {
   if (!data || !isBinsArray(data.bins) || data.bins.length < 3 || !Number.isFinite(centerHz)) {
     return null;
   }
@@ -4428,13 +4436,30 @@ function estimateOccupiedBandwidth(data, centerHz) {
   // 60 kHz mode floor above: a narrower filter trades stereo/RDS content for
   // a useful improvement in intelligibility when the signal is very poor.
   rawBw *= isWfm ? 1.08 : 1.12;
+  if (isWfm) {
+    const aci = Math.max(0, Math.min(100, Number(interference.aci) || 0)) / 100;
+    const cci = Math.max(0, Math.min(100, Number(interference.cci) || 0)) / 100;
+    // Adjacent-channel energy is outside the wanted modulation, so ACI can
+    // safely drive the cap all the way from the 300 kHz ceiling to 60 kHz.
+    const aciCap = maxBw - (maxBw - minBw) * aci;
+    // CCI overlaps the wanted station and cannot be removed by an RF filter.
+    // Only distrust the widest edge estimates, retaining at least 65% of the
+    // useful range between the weak-signal floor and nominal WFM bandwidth.
+    const cciFloor = minBw + (defaultBw - minBw) * 0.65;
+    const cciCap = maxBw - (maxBw - cciFloor) * cci;
+    rawBw = Math.min(rawBw, aciCap, cciCap);
+  }
   const clamped = Math.max(minBw, Math.min(maxBw, rawBw));
   return Math.max(stepBw, Math.round(clamped / stepBw) * stepBw);
 }
 
 async function applyAutoBandwidth() {
   if (!lastSpectrumData || lastFreqHz == null) return;
-  const estimated = estimateOccupiedBandwidth(lastSpectrumData, lastFreqHz);
+  // WFM interference telemetry belongs to the primary DSP channel. Do not
+  // apply it to a virtual channel, where it would describe the wrong signal.
+  const onVirtual = typeof vchanIsOnVirtual === "function" && vchanIsOnVirtual();
+  const interference = onVirtual ? {} : { cci: lastWfmCci, aci: lastWfmAci };
+  const estimated = estimateOccupiedBandwidth(lastSpectrumData, lastFreqHz, interference);
   if (!Number.isFinite(estimated) || estimated <= 0) {
     syncBandwidthInput(currentBandwidthHz);
     return;