fix bs and voc_metrics, test=dygraph (#2196)

dygraph/ppdet/metrics/metrics.py

@@ -149,9 +149,9 @@ class VOCMetric(Metric):
         self.detection_map.reset()
 
     def update(self, inputs, outputs):
-        bboxes = outputs['bbox'].numpy()
-        scores = outputs['score'].numpy()
-        labels = outputs['label'].numpy()
+        bboxes = outputs['bbox'][:, 2:].numpy()
+        scores = outputs['bbox'][:, 1].numpy()
+        labels = outputs['bbox'][:, 0].numpy()
         bbox_lengths = outputs['bbox_num'].numpy()
 
         if bboxes.shape == (1, 1) or bboxes is None:

dygraph/ppdet/modeling/proposal_generator/rpn_head.py

@@ -110,7 +110,7 @@ class RPNHead(nn.Layer):
 
         # TODO: Fix batch_size > 1 when testing.
         if self.training:
-            batch_size = im_shape.shape[0]
+            batch_size = inputs['im_shape'].shape[0]
         else:
             batch_size = 1