feat(bt): gain numerique SCO downlink+uplink

components/audio_router/audio_router.c

@@ -39,6 +39,16 @@ static volatile tone_mode_t s_mode      = TONE_NONE;
 static volatile bool        s_tone_idle = true;
 static TaskHandle_t         s_task      = NULL;
 
+/* --- Gain numerique SCO (avec saturation) --- */
+#define SCO_PLAY_GAIN 4   /* downlink : PCM mobile -> ecouteur */
+#define SCO_MIC_GAIN  4   /* uplink   : micro -> mobile */
+static inline int16_t sat16(int32_t v)
+{
+    if (v > 32767) return 32767;
+    if (v < -32768) return -32768;
+    return (int16_t)v;
+}
+
 /* --- Compteurs de diagnostic SCO (temporaires) --- */
 static volatile uint32_t s_dbg_in_bytes = 0;  /* PCM recu du BT (feed_playback) */
 static volatile uint32_t s_dbg_cap = 0;       /* frames micro capturees */
@@ -86,7 +96,7 @@ static void tone_task(void *a)
                 /* Frame complete : mono -> stereo (CVSD double pour 8k->16k) */
                 int frames = 0;
                 for (int i = 0; i < target && frames < FRAME; i++) {
-                    int16_t v = sco_acc[i];
+                    int16_t v = sat16((int32_t)sco_acc[i] * SCO_PLAY_GAIN);
                     buf[frames * 2] = v; buf[frames * 2 + 1] = v; frames++;
                     if (!s_sco_msbc && frames < FRAME) {
                         buf[frames * 2] = v; buf[frames * 2 + 1] = v; frames++;
@@ -194,6 +204,7 @@ static void sco_mic_task(void *a)
         int n = hal_i2s_capture_read_frame(mono, FRAME, &e);
         if (n <= 0) { vTaskDelay(pdMS_TO_TICKS(5)); continue; }
         s_dbg_cap++;
+        for (int i = 0; i < n; i++) mono[i] = sat16((int32_t)mono[i] * SCO_MIC_GAIN);
         if (s_sco_msbc) {
             /* 16 kHz direct : envoyer tel quel */
             xRingbufferSend(s_sco_cap_rb, mono, (size_t)(n * (int)sizeof(int16_t)), 0);