Lower accompaniment by one octave for #IV and V-VII chords.

AutoBand ignores input octave, so shift engine MIDI output by -12 for those chords (except drums) to keep the range from low #IV up to natural IV.

Co-authored-by: Cursor <cursoragent@cursor.com>

APP/app_adc.c

@@ -303,6 +303,14 @@ void app_adc_sync_volume(uint16_t val)
     app_adc_volume_map_level(val);
 }
 
+/* 取当前主音量（复用扫描任务维护的最近一次有效值）。
+ * 模拟开关同一时刻只选中一路，离开扫描上下文直接重读 ADC 会串到
+ * 其它通道，故统一走 vol_last；未初始化（0xFFFF）时按静音兜底 */
+uint8_t app_adc_get_volume(void)
+{
+    return (vol_last > 127) ? 0 : (uint8_t)vol_last;
+}
+
 static void app_adc_volume_process(void)
 {
     uint16_t val = ADC_ReadChannel(ADC_CHANNEL_1)>>5;

APP/app_adc.h

@@ -27,4 +27,6 @@ void app_adc_in1_scan_part(uint8_t channel);
 bool app_adc_usb_is_plugged(void);
 /* 开机/主动采样后同步 vol_last 与 level，避免扫描任务误触发或跳变 */
 void app_adc_sync_volume(uint16_t val);
+/* 取当前主音量（0~127），供 MasterVolume_Reapply 等重发场景使用 */
+uint8_t app_adc_get_volume(void);
 #endif

APP/app_tm1629.c

@@ -3,7 +3,7 @@
 static uint8_t  key_last = KEY_NONE;
 
 
-/* LED 期望颜色缓存：索引 = LedNum_TypeDef（0~7），COLOR_OTHER 表示灭 */
+/* LED ??????????¹×???? = LedNum_TypeDef??0~7????COLOR_OTHER ????? */
 //static LedColor_TypeDef led_cache[8] = {
 //    COLOR_OTHER, COLOR_OTHER, COLOR_OTHER, COLOR_OTHER,
 //    COLOR_OTHER, COLOR_OTHER, COLOR_OTHER, COLOR_OTHER
@@ -31,7 +31,12 @@ uint8_t app_tm1629_Scan_Key(void)
   if(key != key_last)
   {
     key_last = key;
-    LOG_I("KEY", "tm1629 key=%u", (unsigned)key);
+    if(key >= 1 && key <= 21)
+        LOG_I("KEY", "tm1629 key=%u pitch=%u type=%u", (unsigned)key,
+              (unsigned)chord_type_index_map[key].PitchOffset,
+              (unsigned)chord_type_index_map[key].type);
+    else
+        LOG_I("KEY", "tm1629 key=%u", (unsigned)key);
     TM1629_Handle(key);
     return key;
   }

Global/Global.c

@@ -460,6 +460,16 @@ void Send_volume(uint8_t vol)
   SendMidiDataToDreamDSP(mMasterSysExVolume,12);
 }
 
+/* 重发当前主音量：开机补发 / 进模式主页 / 开始播放前调用。
+ * Dream 上电早期可能丢 SysEx，丢失后旋钮不动就不再重发，
+ * 会出现"图标低音量、实际音量大"；在关键时机重发可自愈 */
+void MasterVolume_Reapply(void)
+{
+  uint8_t vol = app_adc_get_volume();
+  app_adc_sync_volume(vol); /* 兜底刷新 level，保证图标与下发值一致 */
+  Send_volume(vol);
+}
+
 void Accomp_UpdatePlayingChord(void)
 {
   uint8_t midi_note_buff[4] = {0,};
@@ -494,6 +504,8 @@ void ADC_IN1_KEY_Handle(uint8_t key,bool on)
           case 1: AutoBandTop1_Postamble(0); break;
           case 2: AutoBandTop1_Postamble(1); break;
       }
+      /* 前奏/尾奏起奏前补发主音量，保证与图标一致 */
+      MasterVolume_Reapply();
       //AutoBandTop1_Start();
       AutoBandTop1_SyncStart();
       wk_delay_ms(50);
@@ -761,6 +773,10 @@ void Pick_Handle()
   note_cnt = GetChordNotesByType(chord_id, chord_type_index_map[chord_id].type, midi_note_buff);
   Return_Light_buff(KEY_ID_1629);
 
+  /* 首次起奏前补发主音量：防开机 SysEx 丢失后"图标低、实际大" */
+  if (StartFlag == 0)
+      MasterVolume_Reapply();
+
   switch(mGuiData[GUI_TAB_INDEX].Current)
   {
       case 3:

Global/Global.h

@@ -213,6 +213,7 @@ uint8_t GUI_Item_AjustValue(GUI_SWITCH * Group, int8_t Dir);
 void GUI_Item_AjustLoopValue(GUI_SWITCH * Group, int8_t Dir);
 
 void Send_volume(uint8_t vol);
+void MasterVolume_Reapply(void);
 
 void ADC_IN1_KEY_Handle(uint8_t key,bool on);
 void TM1617_Handle(uint8_t key);

MyCode/App_Auto.c

@@ -19,6 +19,64 @@ static uint8_t pStoreBuffer[PRESET_BUFFER_SIZE];
 //static uint8_t* pStoreBuffer;
 #define DEFAULT_TEMPO 100
 
+/* ======== 路线A：#IV 降八度拦截（音师库支持八度前的临时方案） ========
+ * AutoBand 库对输入音符只做音级识别，输出音区由其内部 octaveBase 决定，
+ * 固件侧在 GetChordNotesByType 里的低八度设计不可听。故在引擎输出回调处
+ * 按当前和弦状态对旋律通道做条件性八度偏移；音师新库到位后整体移除。 */
+#define CHORD_OCTAVE_INTERCEPT_EN   1
+#define DRUM_CHANNEL                9   /* 鼓通道不移调 */
+
+/* 当前生效的八度偏移（0 或 -12）。RAM 余量极小，不用按音符表：
+ * 状态翻转瞬间先向旋律通道补 CC123(All Notes Off) 清掉旧音区的音，
+ * 之后 NoteOff 统一按当前偏移还原即可，不会挂音。 */
+static int8_t s_chord_octave_shift = 0;
+
+static int8_t App_Auto_TargetChordOctaveShift(void)
+{
+#if CHORD_OCTAVE_INTERCEPT_EN
+    /* 与 GetChordNotesByType 的根音八度设计对齐（整段伴奏压一个八度）：
+     * V/VI/VII（键 13~21）根音本就在低八度（43/45/47）；
+     * #IV（键 10~12 + Pitch 升）整组低八度，为最低音。
+     * 引擎只认音级不认八度，故在输出侧统一补 -12。 */
+    if (KEY_ID_1629 >= 13 && KEY_ID_1629 <= 21)
+        return -12;
+    if (KEY_ID_1629 >= 10 && KEY_ID_1629 <= 12 &&
+        chord_type_index_map[KEY_ID_1629].PitchOffset == 2)
+        return -12;
+#endif
+    return 0;
+}
+
+static void App_Auto_QueueAllNotesOff(void)
+{
+    MidiFifoItem_t m;
+    for (int ch = 0; ch < 16; ch++)
+    {
+        if (ch == DRUM_CHANNEL) continue;
+        m.msg[0] = 0xB0 | ch;
+        m.msg[1] = 123;  /* CC123 All Notes Off */
+        m.msg[2] = 0;
+        m.msglen = 3;
+        mymidififo_InQueue(&m_MidiSendFifo,&m);
+    }
+}
+
+/* NoteOn 路径调用：偏移状态翻转时先清旧音，再返回新偏移 */
+static int8_t App_Auto_ShiftForNoteOn(void)
+{
+    int8_t target = App_Auto_TargetChordOctaveShift();
+    if (target != s_chord_octave_shift)
+    {
+        LOG_I("OCT", "shift %d->%d chord=%u pitch=%u",
+              (int)s_chord_octave_shift, (int)target,
+              (unsigned)KEY_ID_1629,
+              (unsigned)chord_type_index_map[KEY_ID_1629].PitchOffset);
+        App_Auto_QueueAllNotesOff();
+        s_chord_octave_shift = target;
+    }
+    return s_chord_octave_shift;
+}
+
 static void Func_CallBack_ProgramChange(int channel, int program)
 {
     MidiFifoItem_t midimsg;
@@ -32,8 +90,15 @@ static void Func_CallBack_ProgramChange(int channel, int program)
 static void Func_CallBack_NoteOff(int channel,int key)
 {
     MidiFifoItem_t midimsg;
-    midimsg.msg[0] = 0x80 | channel;
-    midimsg.msg[1] = key;
+    int out_key = key;
+    if (channel != DRUM_CHANNEL && key >= 0 && key < 128)
+    {
+        /* 按当前偏移还原；偏移翻转瞬间的旧音已由 CC123 清掉 */
+        out_key = key + s_chord_octave_shift;
+        if (out_key < 0 || out_key > 127) out_key = key;
+    }
+    midimsg.msg[0] = 0x80 | (channel & 0x0F);
+    midimsg.msg[1] = (uint8_t)out_key;
     midimsg.msg[2] = 0;
     midimsg.msglen = 3;
     mymidififo_InQueue(&m_MidiSendFifo,&midimsg);
@@ -43,9 +108,17 @@ static void Func_CallBack_NoteOff(int channel,int key)
 static void Func_CallBack_NoteOn(int channel,int key,int vel)
 {
     MidiFifoItem_t midimsg;
-    midimsg.msg[0] = 0x90 | channel;
-    midimsg.msg[1] = key;
-    midimsg.msg[2] = vel;
+    int out_key = key;
+    if (channel != DRUM_CHANNEL && key >= 0 && key < 128)
+    {
+        int8_t shift = (vel == 0) ? s_chord_octave_shift   /* vel=0 视同 NoteOff */
+                                  : App_Auto_ShiftForNoteOn();
+        out_key = key + shift;
+        if (out_key < 0 || out_key > 127) out_key = key;
+    }
+    midimsg.msg[0] = 0x90 | (channel & 0x0F);
+    midimsg.msg[1] = (uint8_t)out_key;
+    midimsg.msg[2] = (uint8_t)vel;
     midimsg.msglen = 3;
     mymidififo_InQueue(&m_MidiSendFifo,&midimsg);
 
@@ -135,6 +208,7 @@ static int Func_CallBack_ReadFlash(int address,int length,uint8_t* pOutput)
 //
 void App_Auto_Init(void)
 {
+    LOG_I("OCT", "intercept build 20260910 en=%d", (int)CHORD_OCTAVE_INTERCEPT_EN);
     AutoBandTop1_SetPresetStoreBuffer(pStoreBuffer,PRESET_BUFFER_SIZE);
     AutoBandTop1_Init();
     AutoBandTop1_RegisterCallBack_NoteOn(Func_CallBack_NoteOn);

UI/UI_Idle.c

@@ -163,11 +163,11 @@ void IdleProcess(DisplayTaskMessage_Type msg)
             TM1629D_UpdateDisplay(0);
             StartTouchTask();
             StartScanTask();
-            /* Dream 上电稍后可能忽略首包 SysEx：再发主音量 + 调音台（保持关机前设置） */
+            /* Dream 上电稍后可能忽略首包 SysEx：再发主音量 + 调音台（保持关机前设置）。
+             * 此时扫描任务已启动、模拟开关在轮询，不可现场重读 ADC（会串通道），
+             * 统一用 MasterVolume_Reapply 取扫描任务维护的最近一次有效音量 */
             rt_thread_mdelay(400);
-            vol = ADC_ReadChannel(ADC_CHANNEL_1)>>5;
-            app_adc_sync_volume(vol);
-            Send_volume(vol);
+            MasterVolume_Reapply();
             LoadConfig();
             Draw_Volume_Bar(UI0902_VOL_X, UI0902_VOL_Y, level, 1, WHITE, GRAY);
         break;

UI/UI_Mixer.c

@@ -244,7 +244,7 @@ void UI_Mixer_Process(DisplayTaskMessage_Type msg)
   break;
 
   case MSG_ID_EC_VOL:
-    Draw_Volume_Bar(UI0902_VOL_X, UI0902_VOL_Y, msg.HiByte, 1, WHITE, GRAY);
+    /* 调音台子页无状态栏音量条（与返回键重叠）；主音量已在 MainTask 下发 */
     ResetAutoPowerCount();
   break;
   }

UI/UI_SongMode.c

@@ -243,6 +243,8 @@ void Touch_Action(int8_t FLAG, uint8_t ID, uint8_t areaIndex,uint8_t value)
           AutoBandTop1_SetRunVar(mGuiData[ID].Current); 
         }else
         {
+          /* 触摸起奏前补发主音量，保证实际音量与图标一致 */
+          MasterVolume_Reapply();
           AutoBandTop1_FillinWithIndex(value);
           AutoBandTop1_Start();
         }

UI/UI_SystemSet.c

@@ -124,6 +124,11 @@ void UI_SystemSet_Process(DisplayTaskMessage_Type msg)
 			label_top();
 			break;
 
+		case MSG_ID_EC_VOL:
+			/* 主音量已在 MainTask 下发；此处只刷新状态栏音量条，保证与旋钮一致 */
+			Draw_Volume_Bar(UI0902_VOL_X, UI0902_VOL_Y, msg.HiByte, 1, WHITE, GRAY);
+			break;
+
 		default:
 			break;
 	}

UI/UI_global.c

@@ -54,6 +54,7 @@ void CallUI_Idle(void) {
 
 void CallUI_SongMode(void) {
   app_touch_suppress(500);
+  MasterVolume_Reapply(); /* 进模式补发主音量，防开机 SysEx 丢失后实际音量与图标不符 */
   UI_SongMode_Init();
   CurrUIProcress = UI_SongMode_Process;
   app_log_set_ui_page("Song");
@@ -62,6 +63,7 @@ void CallUI_SongMode(void) {
 
 void CallUI_ExpertMode(void) {
   app_touch_suppress(500);
+  MasterVolume_Reapply();
    UI_ExpertMode_Init();
 //  CurrUIProcress = UI_ExpertMode_Process;
   CurrUIProcress = UI_SongMode_Process;
@@ -71,6 +73,7 @@ void CallUI_ExpertMode(void) {
 
 void CallUI_FreeMode(void) {
   app_touch_suppress(500);
+  MasterVolume_Reapply();
    UI_FreeMode_Init();
 //  CurrUIProcress = UI_FreeMode_Process;
   CurrUIProcress = UI_SongMode_Process;