Files
stable-diffusion.cpp/scripts/convert_yolov8_to_safetensors.py
2026-07-14 23:59:11 +08:00

87 lines
3.1 KiB
Python

#!/usr/bin/env python3
"""Convert an Ultralytics YOLOv8 detection checkpoint for sd.cpp ADetailer."""
import argparse
import json
from pathlib import Path
def parse_args():
parser = argparse.ArgumentParser(
description="Convert an Ultralytics YOLOv8 detection .pt checkpoint to safetensors."
)
parser.add_argument("input", type=Path, help="input YOLOv8 detection checkpoint")
parser.add_argument("output", type=Path, help="output safetensors path")
parser.add_argument(
"--input-size", type=int, default=640, help="detector input size metadata (default: 640)"
)
return parser.parse_args()
def main():
args = parse_args()
if args.input_size < 32 or args.input_size % 32 != 0:
raise ValueError("--input-size must be a positive multiple of 32")
if args.output.suffix.lower() != ".safetensors":
raise ValueError("output path must use the .safetensors extension")
try:
import torch
from safetensors.torch import save_file
from ultralytics import YOLO
from ultralytics.nn.modules.head import Detect
except ImportError as exc:
raise SystemExit("conversion requires ultralytics, torch, and safetensors") from exc
torch_load = torch.load
def load_trusted_checkpoint(*load_args, **load_kwargs):
load_kwargs.setdefault("weights_only", False)
return torch_load(*load_args, **load_kwargs)
torch.load = load_trusted_checkpoint
try:
yolo = YOLO(str(args.input))
finally:
torch.load = torch_load
network = yolo.model
if not isinstance(network.model[-1], Detect) or network.model[-1].__class__.__name__ != "Detect":
raise ValueError("only YOLOv8 detection checkpoints are supported; segmentation is not yet supported")
network.eval()
network.fuse()
state_dict = network.state_dict()
required = {
"model.0.conv.weight",
"model.22.cv2.0.2.weight",
"model.22.cv3.0.2.weight",
}
missing = sorted(required.difference(state_dict))
if missing:
raise ValueError(f"checkpoint does not match the supported YOLOv8 layout; missing {missing}")
tensors = {}
for name, tensor in state_dict.items():
if not name.startswith("model.") or ".bn." in name or name.endswith("dfl.conv.weight"):
continue
if not (name.endswith(".weight") or name.endswith(".bias")):
continue
dtype = torch.float16 if name.endswith(".weight") else torch.float32
tensors[name] = tensor.detach().to(device="cpu", dtype=dtype).contiguous()
metadata = {
"format": "pt",
"yolov8.variant": "detect",
"yolov8.input_size": str(args.input_size),
"yolov8.num_classes": str(int(network.model[-1].nc)),
"yolov8.reg_max": str(int(network.model[-1].reg_max)),
"yolov8.names": json.dumps(yolo.names, ensure_ascii=False),
}
args.output.parent.mkdir(parents=True, exist_ok=True)
save_file(tensors, str(args.output), metadata=metadata)
print(f"wrote {args.output}: {len(tensors)} tensors")
if __name__ == "__main__":
main()