CAIN VFI

Documentation

• Class name: CAIN VFI
• Category: ComfyUI-Frame-Interpolation/VFI
• Output node: False

The CAIN_VFI node is designed for video frame interpolation, leveraging deep learning models to predict intermediate frames between existing ones in a video sequence. It focuses on enhancing video fluidity and frame rate by generating high-quality intermediate frames.

Input types

Required

• ckpt_name
  • Specifies the checkpoint name for loading the pre-trained CAIN model, which is essential for initializing the model with learned weights for frame interpolation.
  • Comfy dtype: COMBO[STRING]
  • Python dtype: str
• frames
  • The input frames to be interpolated. This tensor contains the consecutive frames between which the intermediate frames are to be generated.
  • Comfy dtype: IMAGE
  • Python dtype: torch.Tensor
• clear_cache_after_n_frames
  • Determines after how many frames the cache should be cleared to manage memory usage efficiently during the interpolation process.
  • Comfy dtype: INT
  • Python dtype: int
• multiplier
  • Defines the factor by which the frame rate is to be increased, indicating how many intermediate frames are to be generated between each pair of original frames.
  • Comfy dtype: INT
  • Python dtype: int

Optional

• optional_interpolation_states
  • Allows for the passing of optional states that can influence the interpolation process, providing flexibility in handling different interpolation scenarios.
  • Comfy dtype: INTERPOLATION_STATES
  • Python dtype: InterpolationStateList

Output types

• image
  • Comfy dtype: IMAGE
  • The output tensor containing the interpolated frames, enhancing the video's fluidity by filling in the gaps between original frames.
  • Python dtype: torch.Tensor

Usage tips

• Infra type: GPU
• Common nodes: unknown

Source code

class CAIN_VFI:
    @classmethod
    def INPUT_TYPES(s):
        return {
            "required": {
                "ckpt_name": (CKPT_NAMES, ),
                "frames": ("IMAGE", ),
                "clear_cache_after_n_frames": ("INT", {"default": 10, "min": 1, "max": 1000}),
                "multiplier": ("INT", {"default": 2, "min": 2, "max": 1000})
            },
            "optional": {
                "optional_interpolation_states": ("INTERPOLATION_STATES", )
            }
        }

    RETURN_TYPES = ("IMAGE", )
    FUNCTION = "vfi"
    CATEGORY = "ComfyUI-Frame-Interpolation/VFI"

    def vfi(
        self,
        ckpt_name: typing.AnyStr, 
        frames: torch.Tensor, 
        clear_cache_after_n_frames: typing.SupportsInt = 1,
        multiplier: typing.SupportsInt = 2,
        optional_interpolation_states: InterpolationStateList = None,
        **kwargs
    ):
        from .cain_arch import CAIN
        model_path = load_file_from_github_release(MODEL_TYPE, ckpt_name)
        sd = torch.load(model_path)["state_dict"]
        sd = {key.replace('module.', ''): value for key, value in sd.items()}


        global interpolation_model
        interpolation_model = CAIN(depth=3)
        interpolation_model.load_state_dict(sd)
        interpolation_model.eval().to(get_torch_device())
        del sd

        frames = preprocess_frames(frames)


        def return_middle_frame(frame_0, frame_1, timestep, model):
            #CAIN does some direct modifications to input frame tensors so we need to clone them
            return model(frame_0.detach().clone(), frame_1.detach().clone())[0]

        args = [interpolation_model]
        out = postprocess_frames(
            generic_frame_loop(frames, clear_cache_after_n_frames, multiplier, return_middle_frame, *args, 
                               interpolation_states=optional_interpolation_states, use_timestep=False, dtype=torch.float32)
        )
        return (out,)