Fix demo bugs.

app.py

@@ -136,15 +136,15 @@ def generate(image, video, message, chatbot, textbox_in, temperature, top_p, max
         if len(previous_image) > 0:
             previous_image = previous_image[0]
             # 2.1 new image append or pure text input will start a new conversation
-            if previous_image != image:
+            if image is not None and os.path.basename(previous_image) != os.path.basename(image):
                 message.clear()
-                one_turn_chat[0] += "\n" + show_images if image is not None else ""
+                one_turn_chat[0] += "\n" + show_images
         elif len(previous_video) > 0:
             previous_video = previous_video[0]
             # 2.2 new video append or pure text input will start a new conversation
-            if previous_video != video:
+            if video is not None and os.path.basename(previous_video) != os.path.basename(video):
                 message.clear()
-                one_turn_chat[0] += "\n" + show_images if video is not None else ""
+                one_turn_chat[0] += "\n" + show_images
 
     message.append({'role': 'user', 'content': textbox_in})
     text_en_out = handler.generate(data, message, temperature=temperature, top_p=top_p, max_output_tokens=max_output_tokens)