Phantom-Wan-1.3B — MLX

Apple-MLX port of Phantom-Wan-1.3B (ByteDance, ICCV 2025) — multi-subject subject-to-video (S2V): compose up to 4 distinct characters from reference images into one coherent generated video. Runs natively on Apple Silicon. Apache-2.0.

Phantom-Wan-1.3B is a fine-tune of the stock Wan2.1-T2V-1.3B DiT, so this port rides the mlx-video Wan2.1 substrate; the only net-new surface is the reference-injection path (refs encoded as trailing temporal latent frames + dual-scale chained CFG).

Contents (self-contained)

File	What
transformer-bf16.safetensors	DiT, bf16 (2.84 GB)
transformer-4bit.safetensors	DiT, int4 group-size 64 (0.98 GB) — embeds/time/head kept hi-precision, cosine 0.99633 vs bf16
vae-encoder.safetensors / vae-decoder.safetensors	Wan2.1 16-ch VAE (bf16)
t5_encoder.safetensors	umT5-XXL text encoder (bf16)
config.json	architecture + sampling defaults

Features

• Multi-subject (≤4 refs) composition from reference sheets.
• Lossless streaming VAE decode — peak memory flat ~20 GB at any video length; 81-frame output decodes fine (whole-sequence decode OOMs past ~49 frames).
• Dual-scale chained CFG (guide_img=5.0, guide_text=7.5), FlowUniPC scheduler (shift 5, 50 steps).

Usage

from phantom_wan_mlx import pipeline_mlx as P   # github.com/xocialize/phantom-wan-mlx
P.s2v(
    "two friends walking together in a park",
    ["subjectA.png", "subjectB.png"],
    "out.mp4",
    size=(832, 480), frame_num=81,
)

Parity

DiT loads turnkey into the mlx-video WanModel (825/826 keys; the gap is the computed RoPE buffer); forward + VAE numerics inherited from the published mlx-video / Bernini-R Wan2.1 substrate. Streaming decode is bit-exact to whole-sequence decode on mx.cpu.

License

Apache-2.0 (mirrors upstream Phantom + Wan2.1). Port by MVS Collective (xocialize-code).