+    //init 
+    obj->channel_params.active_channel_id = 2;
+    obj->switch_preproc_ch_obj = vxCreateUserDataObject(obj->context, "tivx_preproc_select_channel_params_t", sizeof(tivx_preproc_select_channel_params_t),&obj->channel_params); 
+    status = vxGetStatus((vx_reference)obj->switch_preproc_ch_obj);



+static vx_status SendCmdtoPreProc(AppObj *obj,PreProcObj *preProcObj)
+{
+    
+    if(obj->switch_preproc_ch_obj == NULL)
+        {
+            vx_status status = VX_FAILURE;
+            return status;
+        }
+    
+    
+    vx_reference refs[1];
+    vx_status status = VX_FAILURE;
+
+    obj->channel_params.active_channel_id = (obj->channel_params.active_channel_id + 1) % NUM_CAPT_CHANNELS_TOTAL;
+    APP_PRINTF("active_channel_id:%d\n",obj->channel_params.active_channel_id);
+    vxCopyUserDataObject(obj->switch_preproc_ch_obj, 0,
+                    sizeof(tivx_preproc_select_channel_params_t),
+                    &obj->channel_params, VX_WRITE_ONLY, VX_MEMORY_TYPE_HOST);
+    refs[0] = (vx_reference) obj->switch_preproc_ch_obj;
+    status = tivxNodeSendCommand(preProcObj->node, 0u, TIVX_PREPROC_SELECT_CHANNEL, refs, 1u);
+    APP_PRINTF("App Send Preproc Command Done!\n");
+
+    if(status != VX_SUCCESS)
+    {
+        APP_PRINTF("PreProc: Node send command failed!\n");
+    }
+
+    return status;
+}
+




+            if(status == VX_SUCCESS )
+            {
+                status = SendCmdtoPreProc(obj,&obj->preProcObj);
+            }