Reverse Frame Sequence

Reverse Frame Sequence flips a clip's frames back-to-front. Last frame becomes first, first becomes last, everything in between mirrors. The README puts it plainly: "Inverse the order of the images in a frame sequence with this node to easily reverse videos." It's about as simple as a node gets, and it's more useful than it sounds.

It's a small piece of DoctorDiffusion's MediaMixer pack, the video-utility suite, and it earns its place because reversing frames comes up constantly once you start doing anything beyond single-shot generation.

Why reverse a video?

Three reasons people actually use it.

The obvious one: you want the clip to play backwards. Water flowing up, a shatter reassembling, a walk-away turned into a walk-toward. Cheap and effective.

Seamless loops. Play a clip forward, then reverse, and you get a boomerang that returns to exactly where it started - no visible cut, because the last frame of the forward pass is the first frame of the reverse. Great for short ambient loops where a hard restart would be jarring.

Backward extension. This is the clever one. Video models extend forward - they generate what comes next from a starting frame. If you want to generate what came before your clip, you reverse it, extend forward from the now-final frame (which was really your original opening), then reverse the whole thing back. Reverse Frame Sequence is both halves of that sandwich. Pair it with First Frame Selector and Video Merge from this same pack and you've got a complete prequel-generation loop.

Mechanically there's no mystery: a ComfyUI "video" is just a batch of IMAGE frames in order, and this node returns that same batch with the order flipped. No resampling, no interpolation, no quality loss - the exact same pixels, walked in reverse.

Inputs and outputs

There's nothing to configure:

• Images (IMAGE) - the clip you want reversed. Wire in a frame batch from a sampler or a Load Video node.

The single IMAGE output is that batch in reverse order. Feed it into a Video Combine node to render it out, into a Video Merge to bolt it onto another clip, or back into a sampler as the starting point for a backward extension.

Installing it

ComfyUI Manager: search MediaMixer, install, restart. Or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/DoctorDiffusion/ComfyUI-MediaMixer.git
cd ComfyUI-MediaMixer
pip install -r requirements.txt

then restart. No models, no heavy dependencies for this node.

Almost nothing to troubleshoot

This is a pure reordering operation, so it basically can't misbehave. The only "issues" are conceptual.

It reverses frames, not audio. If your clip has a soundtrack attached elsewhere in the workflow, flipping the frames won't flip the audio to match - you'll get forward sound over backward picture. Handle the audio separately if you care about it.

And keep your reversals straight when you're doing the backward-extension trick. Reverse in, generate, reverse out - miss one and you'll end up with a clip that plays the wrong way while everything looks technically correct. When in doubt, drop a quick preview after each reverse so you can see which direction time is running. That's genuinely the whole list; this node does one thing and doesn't get in your way.