Fix: Replace gr.Video with HTML video tag to prevent freezing

Problem: Video display was freezing/hanging the webpage even though API calls were successful

Root Cause: Gradio Video component was trying to preload entire videos from CDN, causing hang

Solution: Use HTML5 video tag with gr.HTML component instead:
- Native browser video player (no preload issues)
- More responsive and faster
- Added download link and open in new tab options
- Prevents Gradio from trying to cache/preload large video files

Benefits:
- ✅ No more webpage freezing
- ✅ Instant video display with progressive loading
- ✅ User can download or open videos in new tab
- ✅ Works with CDN URLs without issues

Testing: Verified HTML video tag renders correctly and plays smoothly

app.py

@@ -728,7 +728,7 @@ with gr.Blocks(title="Video Model Evaluator") as demo:
                     
                     for model_name in MODELS_TO_CALL:
                         display_name = MODEL_DISPLAY_NAMES.get(model_name, model_name)
-                        video_components[model_name] = gr.Video(
+                        video_components[model_name] = gr.HTML(
                             label=display_name,
                             visible=False
                         )
@@ -781,11 +781,29 @@ with gr.Blocks(title="Video Model Evaluator") as demo:
         # 为每个模型添加视频和评分组件更新
         for model_name in MODELS_TO_CALL:
             video_value = urls.get(model_name, None)
-            # 返回视频组件更新（包括value和visible）和评分滑块的visible
+            # 返回视频组件更新（使用HTML video标签避免卡顿）
             if video_value:
-                outputs.append(gr.update(value=video_value, visible=True))
+                # 使用HTML video标签，更可控且不会卡顿
+                video_html = f"""
+                <div style="margin: 10px 0;">
+                    <video controls style="width: 100%; max-width: 640px; border-radius: 8px;">
+                        <source src="{video_value}" type="video/mp4">
+                        Your browser does not support the video tag.
+                    </video>
+                    <p style="margin-top: 10px;">
+                        <a href="{video_value}" target="_blank" download style="color: #007bff; text-decoration: none;">
+                            📥 下载视频
+                        </a> |
+                        <a href="{video_value}" target="_blank" style="color: #007bff; text-decoration: none;">
+                            🔗 在新标签页打开
+                        </a>
+                    </p>
+                </div>
+                """
+                outputs.append(gr.update(value=video_html, visible=True))
             else:
-                outputs.append(gr.update(value=None, visible=False))
+                outputs.append(gr.update(value="", visible=False))
+            # 评分滑块可见性
             outputs.append(gr.update(visible=has_results))
         
         # 添加提交按钮可见性、状态变量