[cherry-pick][MOT] fix mot bug (#4590)

ppdet/data/source/mot.py

@@ -367,10 +367,10 @@ class MCMOTDataSet(DetDataset):
         logger.info('Image start index: {}'.format(self.img_start_index))
 
         logger.info('Total identities of each category: ')
-        self.num_identities_dict = sorted(
+        num_identities_dict = sorted(
             self.num_identities_dict.items(), key=lambda x: x[0])
         total_IDs_all_cats = 0
-        for (k, v) in self.num_identities_dict:
+        for (k, v) in num_identities_dict:
             logger.info('Category {} [{}] has {} IDs.'.format(k, cid2cname[k],
                                                               v))
             total_IDs_all_cats += v

ppdet/modeling/mot/utils.py

@@ -121,21 +121,22 @@ def write_mot_results(filename, results, data_type='mot', num_classes=1):
     f = open(filename, 'w')
     for cls_id in range(num_classes):
         for frame_id, tlwhs, tscores, track_ids in results[cls_id]:
+            if data_type == 'kitti':
+                frame_id -= 1
             for tlwh, score, track_id in zip(tlwhs, tscores, track_ids):
                 if track_id < 0: continue
-                if data_type == 'kitti':
-                    frame_id -= 1
-                elif data_type == 'mot':
+                if data_type == 'mot':
                     cls_id = -1
-                elif data_type == 'mcmot':
-                    cls_id = cls_id
 
                 x1, y1, w, h = tlwh
+                x2, y2 = x1 + w, y1 + h
                 line = save_format.format(
                     frame=frame_id,
                     id=track_id,
                     x1=x1,
                     y1=y1,
+                    x2=x2,
+                    y2=y2,
                     w=w,
                     h=h,
                     score=score,