Perfect Looper makes seamless looping videos with sound from MiniMax H3 in ComfyUI
Perfect Looper is a free ComfyUI workflow by CoolBreeze_ that uses MiniMax H3 to make a video, with its audio, loop back onto itself without a visible cut. It works from a prompt, an image or reference pictures, and it can also turn an existing 24 fps clip into a loop.
What it does
First a short anchor clip is made from the prompt. Both of its ends are encoded into the next sampler and masked so they stay fixed, and a second bridge clip is generated that starts with the anchor's last frames and ends with its first frames. The two are then joined with an overlapping crossfade of both picture and audio. You control resolution, anchor and bridge length, overlap size and how many loops to combine, with optional RTX upscaling and frame interpolation. It is set up for Larryvrh's 6-step turbo LoRA and works with any fine-tuned H3 and LoRA stack.
Worth knowing
The author says simple repeating motions loop best; for complex ones a seamless loop is not guaranteed, because the motion has to be able to return to its start in both space and time. Write in the prompt how the bridge should get back to the start, try a different length or seed if you see a hard cut, and avoid generated music, since the beat rarely survives the blend; lay a real track over the loop instead. Saving through the VideoHelperSuite node leaves a little empty audio at the end, so trim 2 to 3 ms before joining loops. The NVIDIA VFX nodes it uses for interpolation need an RTX 40-series card or newer, and one node pack (H3 Motion Context MultiRef) must be installed by hand.
Try it yourself
A continuous row of sheep runs from the left side of the view to the right. Each of them jumps over a fence. Static camera.