diffusers/pipelines/hunyuan_video1_5/image_processor.py

# Copyright 2025 The HunyuanVideo Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np

from ...configuration_utils import register_to_config
from ...video_processor import VideoProcessor


# copied from https://github.com/Tencent-Hunyuan/HunyuanVideo-1.5/blob/main/hyvideo/utils/data_utils.py#L20
def generate_crop_size_list(base_size=256, patch_size=16, max_ratio=4.0):
    num_patches = round((base_size / patch_size) ** 2)
    assert max_ratio >= 1.0
    crop_size_list = []
    wp, hp = num_patches, 1
    while wp > 0:
        if max(wp, hp) / min(wp, hp) <= max_ratio:
            crop_size_list.append((wp * patch_size, hp * patch_size))
        if (hp + 1) * wp <= num_patches:
            hp += 1
        else:
            wp -= 1
    return crop_size_list


# copied from https://github.com/Tencent-Hunyuan/HunyuanVideo-1.5/blob/main/hyvideo/utils/data_utils.py#L38
def get_closest_ratio(height: float, width: float, ratios: list, buckets: list):
    """
    Get the closest ratio in the buckets.

    Args:
        height (float): video height
        width (float): video width
        ratios (list): video aspect ratio
        buckets (list): buckets generated by `generate_crop_size_list`

    Returns:
        the closest size in the buckets and the corresponding ratio
    """
    aspect_ratio = float(height) / float(width)
    diff_ratios = ratios - aspect_ratio

    if aspect_ratio >= 1:
        indices = [(index, x) for index, x in enumerate(diff_ratios) if x <= 0]
    else:
        indices = [(index, x) for index, x in enumerate(diff_ratios) if x >= 0]

    closest_ratio_id = min(indices, key=lambda pair: abs(pair[1]))[0]
    closest_size = buckets[closest_ratio_id]
    closest_ratio = ratios[closest_ratio_id]

    return closest_size, closest_ratio


class HunyuanVideo15ImageProcessor(VideoProcessor):
    r"""
    Image/video processor to preproces/postprocess the reference image/generatedvideo for the HunyuanVideo1.5 model.

    Args:
        do_resize (`bool`, *optional*, defaults to `True`):
            Whether to downscale the image's (height, width) dimensions to multiples of `vae_scale_factor`. Can accept
            `height` and `width` arguments from [`image_processor.VaeImageProcessor.preprocess`] method.
        vae_scale_factor (`int`, *optional*, defaults to `16`):
            VAE (spatial) scale factor. If `do_resize` is `True`, the image is automatically resized to multiples of
            this factor.
        vae_latent_channels (`int`, *optional*, defaults to `32`):
            VAE latent channels.
        do_convert_rgb (`bool`, *optional*, defaults to `True`):
            Whether to convert the image to RGB.
    """

    @register_to_config
    def __init__(
        self,
        do_resize: bool = True,
        vae_scale_factor: int = 16,
        vae_latent_channels: int = 32,
        do_convert_rgb: bool = True,
    ):
        super().__init__(
            do_resize=do_resize,
            vae_scale_factor=vae_scale_factor,
            vae_latent_channels=vae_latent_channels,
            do_convert_rgb=do_convert_rgb,
        )

    def calculate_default_height_width(self, height: int, width: int, target_size: int):
        crop_size_list = generate_crop_size_list(base_size=target_size, patch_size=self.config.vae_scale_factor)
        aspect_ratios = np.array([round(float(h) / float(w), 5) for h, w in crop_size_list])
        height, width = get_closest_ratio(height, width, aspect_ratios, crop_size_list)[0]

        return height, width