aduio mail

internal/audio/recorder.go

@@ -31,6 +31,8 @@ type Recorder struct {
 	bufA   []int16 // From Radio
 	bufB   []int16 // mic
 	twoSrc bool
+	gainA  float64 // From Radio gain (1.0 = unity), guarded by srcMu
+	gainB  float64 // mic gain
 
 	// Mixed output state (guarded by mu).
 	ring   []int16 // last prerollSamples of mixed audio
@@ -38,7 +40,36 @@ type Recorder struct {
 	acc    []int16 // active QSO accumulation (seeded from ring on BeginQSO)
 }
 
-func NewRecorder() *Recorder { return &Recorder{} }
+func NewRecorder() *Recorder { return &Recorder{gainA: 1, gainB: 1} }
+
+// SetGains sets the per-source mix levels (1.0 = unity). Use this to balance a
+// hot mic against quieter rig RX audio. Values ≤0 fall back to unity.
+func (r *Recorder) SetGains(fromGain, micGain float64) {
+	if fromGain <= 0 {
+		fromGain = 1
+	}
+	if micGain <= 0 {
+		micGain = 1
+	}
+	r.srcMu.Lock()
+	r.gainA, r.gainB = fromGain, micGain
+	r.srcMu.Unlock()
+}
+
+// scaleSample applies gain to a sample with clamping.
+func scaleSample(s int16, g float64) int16 {
+	if g == 1 {
+		return s
+	}
+	v := float64(s) * g
+	if v > 32767 {
+		return 32767
+	}
+	if v < -32768 {
+		return -32768
+	}
+	return int16(v)
+}
 
 func (r *Recorder) Running() bool {
 	r.mu.Lock()
@@ -128,7 +159,7 @@ func (r *Recorder) mixTick() {
 		if n > 0 {
 			mixed = make([]int16, n)
 			for i := 0; i < n; i++ {
-				mixed[i] = clampSum(r.bufA[i], r.bufB[i])
+				mixed[i] = clampSum(scaleSample(r.bufA[i], r.gainA), scaleSample(r.bufB[i], r.gainB))
 			}
 			r.bufA = append(r.bufA[:0], r.bufA[n:]...)
 			r.bufB = append(r.bufB[:0], r.bufB[n:]...)
@@ -142,7 +173,9 @@ func (r *Recorder) mixTick() {
 		}
 	} else if len(r.bufA) > 0 {
 		mixed = make([]int16, len(r.bufA))
-		copy(mixed, r.bufA)
+		for i, s := range r.bufA {
+			mixed[i] = scaleSample(s, r.gainA)
+		}
 		r.bufA = r.bufA[:0]
 	}
 	r.srcMu.Unlock()