feat: add end frame auto-detection to Seedance Pro node

- Add optional end_frame parameter to Seedance Pro image-to-video mode
  - Automatically detect and use first+last frame generation when end frame is provided
  - Update documentation to reflect new functionality
  - Maintain backward compatibility with existing workflows

README.md

@@ -61,9 +61,10 @@ pip install -r requirements.txt
   - Output: Video URL (STRING)
   - Use case: Generate videos that maintain style/appearance consistency with reference materials
 
-- **Seedance Pro Text/Image-to-Video**: High-quality video generation
-  - Input: Text prompt, mode selection, optional input image, resolution, ratio, duration
+- **Seedance Pro Text/Image-to-Video**: High-quality video generation with end frame support
+  - Input: Text prompt, mode selection, optional input image, optional end frame, resolution, ratio, duration
   - Output: Video URL (STRING)
+  - Features: Automatic first+last frame detection when end frame is provided in image-to-video mode
   - Use case: Premium quality video generation for professional use
 
 ### Image Generation Nodes (Seed/ImageGeneration)
@@ -98,11 +99,11 @@ pip install -r requirements.txt
 
 ### Video Generation Workflow
 1. **Choose the appropriate video node** based on your input type:
-   - Text only → Seedance Lite Text-to-Video
-   - Single image → Seedance Lite Image-to-Video
-   - Two images → Seedance Lite First+Last Frame
+   - Text only → Seedance Lite Text-to-Video or Seedance Pro (text-to-video mode)
+   - Single image → Seedance Lite Image-to-Video or Seedance Pro (image-to-video mode)
+   - Two images → Seedance Lite First+Last Frame or Seedance Pro (image-to-video mode with end frame)
    - Multiple references → Seedance Lite Reference Images
-   - High quality → Seedance Pro
+   - High quality → Seedance Pro (supports all modes with automatic detection)
 
 2. **Configure parameters**:
    - **Prompt**: Describe what you want in the video
@@ -180,6 +181,7 @@ pip install -r requirements.txt
 - **Be specific in prompts**: Include details about movement, camera angles, and style
 - **Use appropriate ratios**: Match your intended use case (16:9 for landscape, 9:16 for mobile, etc.)
 - **Leverage reference images**: For consistent character/style appearance across videos
+- **Seedance Pro end frame support**: In image-to-video mode, connect an optional end frame to automatically enable first+last frame generation for smoother transitions
 
 ### Image Generation
 - **Detailed prompts work better**: Include style, lighting, composition details

nodes/byteplus_video_node.py

@@ -376,6 +376,7 @@ class SeedanceProNode:
             },
             "optional": {
                 "image": ("IMAGE",),
+                "end_frame": ("IMAGE",),
                 "framepersecond": ("INT", {"default": 24, "min": 24, "max": 24, "step": 1}),
                 "seed": ("INT", {"default": -1, "min": -1, "max": 2147483647}),
                 "camerafixed": ("BOOLEAN", {"default": False}),
@@ -387,13 +388,14 @@ class SeedanceProNode:
     CATEGORY = "Seed/VideoGeneration"
 
     def generate_video(
-        self, 
-        prompt, 
+        self,
+        prompt,
         mode,
-        resolution, 
-        ratio, 
+        resolution,
+        ratio,
         duration,
         image=None,
+        end_frame=None,
         framepersecond=24,
         seed=-1,
         camerafixed=False
@@ -419,19 +421,20 @@ class SeedanceProNode:
                 }
             ]
             
-            # Add image if in image-to-video mode
+            # Add image(s) if in image-to-video mode
             if mode == "image-to-video":
                 if image is None:
                     return BytePlusApiHandler.handle_video_generation_error(
                         "Seedance Pro", "Image is required for image-to-video mode"
                     )
-                
+
+                # Convert first frame
                 image_base64 = BytePlusImageUtils.image_to_base64(image)
                 if not image_base64:
                     return BytePlusApiHandler.handle_video_generation_error(
                         "Seedance Pro", "Failed to convert image to base64"
                     )
-                
+
                 content.append({
                     "type": "image_url",
                     "image_url": {
@@ -439,6 +442,23 @@ class SeedanceProNode:
                     },
                     "role": "first_frame"
                 })
+
+                # Check if end_frame is provided for first+last frame generation
+                if end_frame is not None:
+                    # Convert last frame
+                    last_frame_base64 = BytePlusImageUtils.image_to_base64(end_frame)
+                    if not last_frame_base64:
+                        return BytePlusApiHandler.handle_video_generation_error(
+                            "Seedance Pro", "Failed to convert end frame image to base64"
+                        )
+
+                    content.append({
+                        "type": "image_url",
+                        "image_url": {
+                            "url": last_frame_base64
+                        },
+                        "role": "last_frame"
+                    })
             
             # Submit to BytePlus API
             video_url = BytePlusApiHandler.submit_and_get_result(