Image List Replace

Filed under the pack's Video category, this is a frame-range editor for an image sequence: pick a slice by index, and swap it out for something else - a single freeze-frame or an entirely different clip - while the rest of the sequence stays untouched. It's the kind of node you reach for when you've got a generated animation that's almost right except for one stretch of frames, and re-generating the whole thing isn't worth it.

How it works

You give it the full images sequence and a start_index/end_index range. By default it targets that range directly; flip invert on and it targets everything outside that range instead - handy if you want to keep a chosen slice and replace everything else around it. Whatever falls inside the targeted range gets replaced with either image_replace (a single image, presumably repeated across the whole targeted range) or images_replace (a full substitute sequence) - these are two different inputs for two different jobs, not interchangeable.

The inputs and outputs that matter

• images (IMAGE, required) - the full sequence to edit.
• start_index / end_index (INT, default 0, required) - the range to target.
• invert (BOOLEAN, default false, required) - target everything except that range instead.
• image_replace (IMAGE, optional) - a single image to substitute in across the targeted range.
• images_replace (IMAGE, optional) - a full sequence to substitute in instead.

Two outputs: images - the full sequence with the replacement applied - and select_images, which is what got targeted, useful for previewing before you trust the full result.

How to install it

Ships with the Mixlab pack.

• ComfyUI Manager: search comfyui-mixlab-nodes, install, restart.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/shadowcz007/comfyui-mixlab-nodes.git, install requirements (install.bat on Windows, or ../../../python_embeded/python.exe -s -m pip install -r requirements.txt), restart.

No model downloads - pure sequence editing.

Common issues & troubleshooting

Not sure exactly which frames got targeted. The schema doesn't spell out whether end_index is inclusive or exclusive - before trusting the full images output, check the select_images output first to confirm you're targeting the frames you actually meant.

Replacement doesn't do anything. Neither image_replace nor images_replace is required - if you leave both disconnected, there's nothing to substitute in. Decide up front which one you need: image_replace for a single repeated frame, images_replace for a full alternate sequence, and wire the right one.

Result looks wrong with invert on. Remember invert flips which side of the range gets replaced - everything outside start_index–end_index instead of inside it. If the wrong portion of your sequence changed, that toggle is the first thing to check.