wan/utils/utils.py

# Copyright 2024-2025 The Alibaba Wan Team Authors. All rights reserved.
import argparse
import binascii
import logging
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:
        logging.info(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)')


def masks_like(tensor, zero=False, generator=None, p=0.2):
    assert isinstance(tensor, list)
    out1 = [torch.ones(u.shape, dtype=u.dtype, device=u.device) for u in tensor]

    out2 = [torch.ones(u.shape, dtype=u.dtype, device=u.device) for u in tensor]

    if zero:
        if generator is not None:
            for u, v in zip(out1, out2):
                random_num = torch.rand(
                    1, generator=generator, device=generator.device).item()
                if random_num < p:
                    u[:, 0] = torch.normal(
                        mean=-3.5,
                        std=0.5,
                        size=(1,),
                        device=u.device,
                        generator=generator).expand_as(u[:, 0]).exp()
                    v[:, 0] = torch.zeros_like(v[:, 0])
                else:
                    u[:, 0] = u[:, 0]
                    v[:, 0] = v[:, 0]
        else:
            for u, v in zip(out1, out2):
                u[:, 0] = torch.zeros_like(u[:, 0])
                v[:, 0] = torch.zeros_like(v[:, 0])

    return out1, out2


def best_output_size(w, h, dw, dh, expected_area):
    # float output size
    ratio = w / h
    ow = (expected_area * ratio)**0.5
    oh = expected_area / ow

    # process width first
    ow1 = int(ow // dw * dw)
    oh1 = int(expected_area / ow1 // dh * dh)
    assert ow1 % dw == 0 and oh1 % dh == 0 and ow1 * oh1 <= expected_area
    ratio1 = ow1 / oh1

    # process height first
    oh2 = int(oh // dh * dh)
    ow2 = int(expected_area / oh2 // dw * dw)
    assert oh2 % dh == 0 and ow2 % dw == 0 and ow2 * oh2 <= expected_area
    ratio2 = ow2 / oh2

    # compare ratios
    if max(ratio / ratio1, ratio1 / ratio) < max(ratio / ratio2,
                                                 ratio2 / ratio):
        return ow1, oh1
    else:
        return ow2, oh2