Wan Video Freeze Frames

If you generate Wan clips with any regularity, you've seen it: the first few frames can come out jittery, twitchy, or just off, before the motion settles into something stable. It's one of the recurring flicker complaints across the Wan subreddits, and re-rolling the whole generation to fix three bad frames is a waste of twenty minutes. WanVideoFreezeFrames ("Wan Video Freeze Frames") is a cheap post-process fix: it takes one clean frame from your clip and holds it over the opening frames.

How it works

Three inputs, no model involved - this is pure frame surgery on the IMAGE batch you already rendered:

• frames - your generated clip.
• source_frame_index - which frame to freeze. Default 0 (the first frame); negative indices count back from the end, so -1 freezes the last frame.
• hold_frames - how many frames to freeze (default 8). This is the knob you actually tune: 6-12 frames at 16fps is roughly a second of hold.
• mode - what to do with the frozen clip:
  • replace_existing (default) - overwrite the first hold_frames frames of the clip in place. Length unchanged.
  • prepend_and_trim - insert the frozen frames at the front, then cut the clip back to its original length. Length unchanged, but everything shifts.
  • prepend_and_extend - insert the frozen frames and keep the added length, so your clip gets longer.

Outputs are frames (the modified batch) and frame_count (an INT of the resulting length) - useful when a save node wants an explicit frame count, or you need to know the new length after prepend_and_extend.

When it's the right tool

This is a cosmetic patch, and it works best on the classic failure: the motion is fine from frame 8 on, but the opening is shaky. Freezing a solid later frame over the bad ones reads as an intentional hold, which looks far better than visible startup jitter. Where it won't help: if the flicker is spread through the whole clip or the model genuinely fell apart, no freeze fixes that - that's a re-roll with different settings or a speed-LoRA check.

The README describes it as an optional post-process node for "freezing the first few frames to reduce Wan startup flicker," and that's exactly the honest scope. Wire it between your VAE Decode and your video save node. Start with the defaults - source_frame_index 0, hold_frames 8, replace_existing - and only reach for prepend_and_extend if you want the clip to linger on a title-style opening frame.

Installing it

Same pack as the rest. Manager search "ComfyUI-Tessiiiz-WanVideoToolkit", or:

cd ComfyUI/custom_nodes
git clone https://github.com/Tessiiiz/ComfyUI-Tessiiiz-WanVideoToolkit

Then restart. No extra dependencies, no models - it's a pure tensor op, which is exactly what you want in a tool whose whole job is not making things worse.