Add demodulation toggle for digital voice

routes/dmr.py

@@ -52,6 +52,7 @@ dmr_active_device: Optional[int] = None
 _active_ffmpeg_stdin: Optional[object] = None  # set by stream endpoint
 
 VALID_PROTOCOLS = ['auto', 'dmr', 'p25', 'p25p2', 'nxdn', 'dstar', 'provoice']
+VALID_DEMODS = ['nfm', 'fm']
 
 # Classic dsd flags
 _DSD_PROTOCOL_FLAGS = {
@@ -489,11 +490,14 @@ def start_dmr() -> Response:
         device = validate_device_index(data.get('device', 0))
         protocol = str(data.get('protocol', 'auto')).lower()
         ppm = validate_ppm(data.get('ppm', 0))
+        demod = str(data.get('demod', 'nfm')).lower()
     except (ValueError, TypeError) as e:
         return jsonify({'status': 'error', 'message': f'Invalid parameter: {e}'}), 400
 
     if protocol not in VALID_PROTOCOLS:
         return jsonify({'status': 'error', 'message': f'Invalid protocol. Use: {", ".join(VALID_PROTOCOLS)}'}), 400
+    if demod not in VALID_DEMODS:
+        return jsonify({'status': 'error', 'message': f'Invalid demod. Use: {", ".join(VALID_DEMODS)}'}), 400
     if protocol == 'p25p2' and not is_fme:
         return jsonify({'status': 'error', 'message': 'P25 Phase 2 requires dsd-fme.'}), 400
 
@@ -521,7 +525,7 @@ def start_dmr() -> Response:
     # internally via its own frame-sync detection.
     rtl_cmd = [
         rtl_fm_path,
-        '-M', 'fm',
+        '-M', demod,
         '-f', str(freq_hz),
         '-s', '48000',
         '-g', str(gain),

static/js/modes/dmr.js

@@ -70,6 +70,7 @@ function startDmr() {
     const gain = parseInt(document.getElementById('dmrGain')?.value || 40);
     const ppm = parseInt(document.getElementById('dmrPPM')?.value || 0);
     const relaxCrc = document.getElementById('dmrRelaxCrc')?.checked || false;
+    const demod = document.getElementById('dmrDemod')?.value || 'nfm';
     const device = typeof getSelectedDevice === 'function' ? getSelectedDevice() : 0;
 
     // Use protocol name for device reservation so panel shows "D-STAR", "P25", etc.
@@ -83,14 +84,14 @@ function startDmr() {
     // Save settings to localStorage for persistence
     try {
         localStorage.setItem(DMR_SETTINGS_KEY, JSON.stringify({
-            frequency, protocol, gain, ppm, relaxCrc
+            frequency, protocol, gain, ppm, relaxCrc, demod
         }));
     } catch (e) { /* localStorage unavailable */ }
 
     fetch('/dmr/start', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ frequency, protocol, gain, device, ppm, relaxCrc })
+        body: JSON.stringify({ frequency, protocol, gain, device, ppm, relaxCrc, demod })
     })
     .then(r => r.json())
     .then(data => {
@@ -617,11 +618,13 @@ function restoreDmrSettings() {
         const gainEl = document.getElementById('dmrGain');
         const ppmEl = document.getElementById('dmrPPM');
         const crcEl = document.getElementById('dmrRelaxCrc');
+        const demodEl = document.getElementById('dmrDemod');
         if (freqEl && s.frequency != null) freqEl.value = s.frequency;
         if (protoEl && s.protocol) protoEl.value = s.protocol;
         if (gainEl && s.gain != null) gainEl.value = s.gain;
         if (ppmEl && s.ppm != null) ppmEl.value = s.ppm;
         if (crcEl && s.relaxCrc != null) crcEl.checked = s.relaxCrc;
+        if (demodEl && s.demod) demodEl.value = s.demod;
     } catch (e) { /* localStorage unavailable */ }
 }
 

templates/partials/modes/dmr.html

@@ -29,6 +29,17 @@
                             </select>
                         </div>
 
+                        <div class="form-group">
+                            <label>Demodulation</label>
+                            <select id="dmrDemod">
+                                <option value="nfm" selected>NFM (recommended)</option>
+                                <option value="fm">FM (wide)</option>
+                            </select>
+                            <span style="font-size: 0.75em; color: var(--text-muted); display: block; margin-top: 2px;">
+                                Narrow FM often improves digital voice decode on 12.5 kHz channels.
+                            </span>
+                        </div>
+
                         <div class="form-group">
                             <label>Gain</label>
                             <input type="number" id="dmrGain" value="40" min="0" max="50" style="width: 100%;">