ex3d cold boot starvation

sw_usb_audio/app_usb_aud_phaten_golden_6ch/src/extensions/dsp.c

@@ -135,6 +135,7 @@ void UserBufferManagementInit(unsigned sampFreq)
 #if USE_EX3D == 1
     memset(ubm_ingress, 0, sizeof(ubm_ingress));
     memset(ubm_egress,  0, sizeof(ubm_egress));
+    frame_index = 0;
 
     assert(uc_ex3d_to_ubm);
     while( !m_hThread ){}
@@ -145,6 +146,12 @@ void UserBufferManagementInit(unsigned sampFreq)
     } else {
         debug_printf("audio_ex3d_change_parameter() success\n\r");
     }
+          // ② 预热：推一个零帧穿过 ex3d，触发所有 worker 加载 + 首次同步
+      chan_out_buf_word(uc_ex3d_to_ubm, (const uint32_t *)ubm_egress,
+                        UBM_TO_EX3D_CHANS * DSP_BLOCK_LENGTH);
+      chan_in_buf_word (uc_ex3d_to_ubm, (uint32_t *)ubm_ingress,
+                        EX3D_TO_UBM_CHANS * DSP_BLOCK_LENGTH);
+      memset(ubm_ingress, 0, sizeof(ubm_ingress));  // 清掉哑帧输出
 #endif
 }
 float fLevel[NUM_USB_CHAN_OUT] = {0,};