[MOT] fix stream predict (#4497)

deploy/pptracking/include/pipeline.h

@@ -79,7 +79,7 @@ class Pipeline {
   void PredictMTMCT(const std::vector<std::string> video_inputs);
 
   // Run pipeline in stream
-  void RunMOTStream(const cv::Mat img, const int frame_id, cv::Mat out_img, std::vector<std::string>& records, std::vector<int>& count_list, std::vector<int>& in_count_list, std::vector<int>& out_count_list);
+  void RunMOTStream(const cv::Mat img, const int frame_id, cv::Mat& out_img, std::vector<std::string>& records, std::vector<int>& count_list, std::vector<int>& in_count_list, std::vector<int>& out_count_list);
   void RunMTMCTStream(const std::vector<cv::Mat> imgs, std::vector<std::string>& records);
 
   void PrintBenchmarkLog(std::vector<double> det_time, int img_num);

deploy/pptracking/src/pipeline.cc

@@ -214,7 +214,7 @@ void Pipeline::PredictMTMCT(const std::vector<std::string> video_path) {
   throw "Not Implement!";
 }
 
-void Pipeline::RunMOTStream(const cv::Mat img, const int frame_id, cv::Mat out_img, std::vector<std::string>& records, std::vector<int>& count_list, std::vector<int>& in_count_list, std::vector<int>& out_count_list) {
+void Pipeline::RunMOTStream(const cv::Mat img, const int frame_id, cv::Mat& out_img, std::vector<std::string>& records, std::vector<int>& count_list, std::vector<int>& in_count_list, std::vector<int>& out_count_list) {
   PaddleDetection::MOTResult result;
   std::vector<double> det_times(3);
   double times;