Files
lewm/scripts/convert_hf_checkpoint.py
2026-05-14 04:27:10 +00:00

132 lines
3.8 KiB
Python

#!/usr/bin/env python
"""Convert LeWM HuggingFace weights into eval-compatible object checkpoints."""
from __future__ import annotations
import argparse
import json
import sys
from pathlib import Path
import stable_pretraining as spt
import torch
REPO_ROOT = Path(__file__).resolve().parents[1]
if str(REPO_ROOT) not in sys.path:
sys.path.insert(0, str(REPO_ROOT))
from jepa import JEPA
from module import ARPredictor, Embedder, MLP
def _load_json(path: Path) -> dict:
with path.open("r", encoding="utf-8") as f:
return json.load(f)
def _strip_target(config: dict) -> dict:
return {key: value for key, value in config.items() if key != "_target_"}
def infer_config_from_state_dict(state_dict: dict) -> dict:
action_dim = state_dict["action_encoder.patch_embed.weight"].shape[1]
return {
"encoder": {
"size": "tiny",
"patch_size": 14,
"image_size": 224,
"pretrained": False,
"use_mask_token": False,
},
"predictor": {
"num_frames": 3,
"input_dim": 192,
"hidden_dim": 192,
"output_dim": 192,
"depth": 6,
"heads": 16,
"mlp_dim": 2048,
"dim_head": 64,
"dropout": 0.1,
"emb_dropout": 0.0,
},
"action_encoder": {
"input_dim": action_dim,
"emb_dim": 192,
},
"projector": {
"input_dim": 192,
"output_dim": 192,
"hidden_dim": 2048,
},
"pred_proj": {
"input_dim": 192,
"output_dim": 192,
"hidden_dim": 2048,
},
}
def build_model(config: dict) -> JEPA:
encoder = spt.backbone.utils.vit_hf(**_strip_target(config["encoder"]))
predictor = ARPredictor(**_strip_target(config["predictor"]))
action_encoder = Embedder(**_strip_target(config["action_encoder"]))
projector_cfg = _strip_target(config["projector"])
projector_cfg["norm_fn"] = torch.nn.BatchNorm1d
projector = MLP(**projector_cfg)
pred_proj_cfg = _strip_target(config["pred_proj"])
pred_proj_cfg["norm_fn"] = torch.nn.BatchNorm1d
pred_proj = MLP(**pred_proj_cfg)
return JEPA(
encoder=encoder,
predictor=predictor,
action_encoder=action_encoder,
projector=projector,
pred_proj=pred_proj,
)
def convert_checkpoint(input_dir: Path, output_name: str) -> tuple[Path, Path]:
config_path = input_dir / "config.json"
weights_path = input_dir / "weights.pt"
if not weights_path.exists():
raise FileNotFoundError(f"Missing weights file: {weights_path}")
state_dict = torch.load(weights_path, map_location="cpu")
config = _load_json(config_path) if config_path.exists() else infer_config_from_state_dict(state_dict)
model = build_model(config)
missing, unexpected = model.load_state_dict(state_dict, strict=True)
if missing or unexpected:
raise RuntimeError(
f"State dict mismatch: missing={missing}, unexpected={unexpected}"
)
model.eval()
object_path = input_dir / f"{output_name}_object.ckpt"
weight_path = input_dir / f"{output_name}_weight.ckpt"
torch.save(model, object_path)
torch.save(model.state_dict(), weight_path)
return object_path, weight_path
def main() -> None:
parser = argparse.ArgumentParser()
parser.add_argument(
"input_dir",
type=Path,
help="Directory containing weights.pt and optionally config.json.",
)
parser.add_argument("--output-name", default="lewm")
args = parser.parse_args()
object_path, weight_path = convert_checkpoint(args.input_dir, args.output_name)
print(f"wrote {object_path}")
print(f"wrote {weight_path}")
if __name__ == "__main__":
main()