ComfyUI-MiniMax-H3-Extend

ComfyUI-MiniMax-H3-Extend

What this does

1. MiniMaxH3VideoExtendPatched node (nodes.py) -- a standalone, directly-usable node exposing the above, plus injection of MiniMaxH3VideoExtend into comfy_extras.nodes_minimax_h3's own namespace (again, only if absent) so anything that looks it up by that name there -- e.g. ComfyUI-H3-Cast's H3CastToVideoExtend -- finds a working implementation transparently, no changes of its own needed.

2. MiniMaxH3EncodeAVPatched node (nodes.py) -- vae-encodes video frames (+ optional audio) into the AV latent MiniMaxH3VideoExtendPatched's (or the native node's) context_latent input needs, for feeding an externally-loaded prior clip (e.g. VHS_LoadVideo) into either. Vendored from the native MiniMaxH3EncodeAV, which isn't part of stock/public support either. Lives here rather than in ComfyUI-H3-Cast since it's an extend/continuation concern, not a cast/character one -- also injected into the native namespace the same way as MiniMaxH3VideoExtend above.

Confirmed working via live testing (2026-08-11) across text-to-video, reference-to-video, and cast-to-video continuation. Recommended starting settings: context_frames 2, ref_spacing 1-2, ref_decay 0.3, ref_ramp 3-4 (5-6 if the prior clip had more motion than usual).

Install

Same as any custom node pack -- clone into custom_nodes/, restart ComfyUI. No core ComfyUI files are edited, and nothing in ComfyUI's model code is touched at import time:

• ComfyUI >= 0.34: the extend node runs entirely on stock's own keyframe support (context frames become ordinary keyframes at negative frame indices). Nothing is patched, ever.
• ComfyUI <= 0.33.x: stock can't anchor keyframes anywhere but the first/ last frame, so PackedLayout/MiniMaxH3.extra_conds patches are installed the first time an extend node actually runs. Even then they pass straight through to stock code for any conditioning this pack didn't build, so other H3 workflows (inpainting, first/last frame, etc.) behave exactly as stock.

To remove: delete this folder, restart.