A simple utility node that counts active Video S2V Extend nodes in your workflow and returns that number plus one. Now you don't have to remember to update the batch number. Just set your extend nodes and go. It was easy to forget so I made this quick and dirty.

What it does

Scans your workflow for active Video S2V Extend nodes
Ignores bypassed nodes automatically
Returns the count + 1 (so 3 extend nodes = output of 4)
Updates every execution - no caching issues
Returns 1 if there are 0 extend nodes or all are bypassed

Installation

Method 1: Git Clone

cd ComfyUI/custom_nodes/
git clone https://github.com/yourusername/Urabewe-CountS2VExtend.git

Method 2: Manual Download

Download this repository as ZIP
Extract to ComfyUI/custom_nodes/Urabewe-CountS2VExtend/
Restart ComfyUI

Usage

Add the node and connect it directly to the "Value" of the "Batch Sizes" node.
Run your workflow and the batch count will update on each run

Why +1?

The Wan 2.2 S2V model counts the sampler node plus all existing extend nodes. Number must be 1 or higher.

Built for native S2V workflows.