空指针导致程序出错

handler/tool.go

@@ -166,6 +166,9 @@ func subscribeAndHandleMessagesV3(ws *websocket.Conn, device_id int) {
 		img, c := service.GetDeviceCurrentFrame(device_id)
 		if c != count {
 			//将img转[]byte
+			if img.Empty() {
+				fmt.Println("device:%d img is empty!", device_id)
+			} else {
 				buf, _ := gocv.IMEncode(".jpg", img)
 				buf1 := buf.GetBytes()
 
@@ -176,6 +179,7 @@ func subscribeAndHandleMessagesV3(ws *websocket.Conn, device_id int) {
 					goto end
 				}
 				c = count
+			}
 		} else {
 			//每秒发送一次心跳检测
 			if t_count%10 == 0 {