replay: do not clear ui image when paused (#22467)

* replay: do not clear ui image when paused

* also stop plots

Co-authored-by: Willem Melching <willem.melching@gmail.com>
old-commit-hash: 720e82eeef

tools/replay/ui.py

@@ -114,7 +114,9 @@ def ui_thread(addr):
 
     rgb_img_raw = vipc_client.recv()
 
-    if rgb_img_raw is not None and rgb_img_raw.any():
+    if rgb_img_raw is None or not rgb_img_raw.any():
+      continue
+
     num_px = len(rgb_img_raw) // 3
     imgff_shape = (vipc_client.height, vipc_client.width, 3)
 
@@ -127,9 +129,6 @@ def ui_thread(addr):
     cv2.warpAffine(imgff, zoom_matrix[:2], (img.shape[1], img.shape[0]), dst=img, flags=cv2.WARP_INVERSE_MAP)
 
     intrinsic_matrix = _INTRINSICS[num_px]
-    else:
-      img.fill(0)
-      intrinsic_matrix = np.eye(3)
 
     sm.update(0)