wan/utils/utils.py

# Copyright 2024-2025 The Alibaba Wan Team Authors. All rights reserved.
import argparse
import binascii
import os
import os.path as osp

import imageio
import torch
import torchvision

__all__ = ["cache_video", "cache_image", "str2bool"]


def rand_name(length=8, suffix=""):
    name = binascii.b2a_hex(os.urandom(length)).decode("utf-8")
    if suffix:
        if not suffix.startswith("."):
            suffix = "." + suffix
        name += suffix
    return name


def cache_video(
    tensor,
    save_file=None,
    fps=30,
    suffix=".mp4",
    nrow=8,
    normalize=True,
    value_range=(-1, 1),
    retry=5,
):
    # cache file
    cache_file = (
        osp.join("/tmp", rand_name(suffix=suffix)) if save_file is None else save_file
    )

    # save to cache
    error = None
    for _ in range(retry):
        try:
            # preprocess
            tensor = tensor.clamp(min(value_range), max(value_range))
            tensor = torch.stack(
                [
                    torchvision.utils.make_grid(
                        u, nrow=nrow, normalize=normalize, value_range=value_range
                    )
                    for u in tensor.unbind(2)
                ],
                dim=1,
            ).permute(1, 2, 3, 0)
            tensor = (tensor * 255).type(torch.uint8).cpu()

            # write video
            writer = imageio.get_writer(cache_file, fps=fps, codec="libx264", quality=8)
            for frame in tensor.numpy():
                writer.append_data(frame)
            writer.close()
            return cache_file
        except Exception as e:
            error = e
            continue
    else:
        print(f"cache_video failed, error: {error}", flush=True)
        return None


def cache_image(
    tensor, save_file, nrow=8, normalize=True, value_range=(-1, 1), retry=5
):
    # cache file
    suffix = osp.splitext(save_file)[1]
    if suffix.lower() not in [".jpg", ".jpeg", ".png", ".tiff", ".gif", ".webp"]:
        suffix = ".png"

    # save to cache
    error = None
    for _ in range(retry):
        try:
            tensor = tensor.clamp(min(value_range), max(value_range))
            torchvision.utils.save_image(
                tensor,
                save_file,
                nrow=nrow,
                normalize=normalize,
                value_range=value_range,
            )
            return save_file
        except Exception as e:
            error = e
            continue


def str2bool(v):
    """
    Convert a string to a boolean.

    Supported true values: 'yes', 'true', 't', 'y', '1'
    Supported false values: 'no', 'false', 'f', 'n', '0'

    Args:
        v (str): String to convert.

    Returns:
        bool: Converted boolean value.

    Raises:
        argparse.ArgumentTypeError: If the value cannot be converted to boolean.
    """
    if isinstance(v, bool):
        return v
    v_lower = v.lower()
    if v_lower in ("yes", "true", "t", "y", "1"):
        return True
    elif v_lower in ("no", "false", "f", "n", "0"):
        return False
    else:
        raise argparse.ArgumentTypeError("Boolean value expected (True/False)")