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imagedream/ldm/modules/diffusionmodules/util.py
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# adopted from
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# https://github.com/openai/improved-diffusion/blob/main/improved_diffusion/gaussian_diffusion.py
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# and
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# https://github.com/lucidrains/denoising-diffusion-pytorch/blob/7706bdfc6f527f58d33f84b7b522e61e6e3164b3/denoising_diffusion_pytorch/denoising_diffusion_pytorch.py
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# and
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# https://github.com/openai/guided-diffusion/blob/0ba878e517b276c45d1195eb29f6f5f72659a05b/guided_diffusion/nn.py
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#
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# thanks!
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import os
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import math
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import torch
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import torch.nn as nn
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import numpy as np
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from einops import repeat
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import importlib
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def instantiate_from_config(config):
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if not "target" in config:
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if config == "__is_first_stage__":
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return None
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elif config == "__is_unconditional__":
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return None
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raise KeyError("Expected key `target` to instantiate.")
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return get_obj_from_str(config["target"])(**config.get("params", dict()))
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def get_obj_from_str(string, reload=False):
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module, cls = string.rsplit(".", 1)
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if reload:
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module_imp = importlib.import_module(module)
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importlib.reload(module_imp)
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return getattr(importlib.import_module(module, package=None), cls)
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-
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def make_beta_schedule(
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schedule, n_timestep, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3
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):
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if schedule == "linear":
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betas = (
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torch.linspace(
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linear_start**0.5, linear_end**0.5, n_timestep, dtype=torch.float64
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)
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** 2
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)
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elif schedule == "cosine":
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timesteps = (
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torch.arange(n_timestep + 1, dtype=torch.float64) / n_timestep + cosine_s
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)
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alphas = timesteps / (1 + cosine_s) * np.pi / 2
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alphas = torch.cos(alphas).pow(2)
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alphas = alphas / alphas[0]
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betas = 1 - alphas[1:] / alphas[:-1]
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betas = np.clip(betas, a_min=0, a_max=0.999)
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elif schedule == "sqrt_linear":
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betas = torch.linspace(
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linear_start, linear_end, n_timestep, dtype=torch.float64
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)
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elif schedule == "sqrt":
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betas = (
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torch.linspace(linear_start, linear_end, n_timestep, dtype=torch.float64)
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** 0.5
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)
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else:
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raise ValueError(f"schedule '{schedule}' unknown.")
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return betas.numpy()
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def enforce_zero_terminal_snr(betas):
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betas = torch.tensor(betas) if not isinstance(betas, torch.Tensor) else betas
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# Convert betas to alphas_bar_sqrt
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alphas =1 - betas
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alphas_bar = alphas.cumprod(0)
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alphas_bar_sqrt = alphas_bar.sqrt()
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# Store old values.
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alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
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alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
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# Shift so last timestep is zero.
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alphas_bar_sqrt -= alphas_bar_sqrt_T
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# Scale so first timestep is back to old value.
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alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
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# Convert alphas_bar_sqrt to betas
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alphas_bar = alphas_bar_sqrt ** 2
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alphas = alphas_bar[1:] / alphas_bar[:-1]
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alphas = torch.cat ([alphas_bar[0:1], alphas])
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betas = 1 - alphas
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return betas
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def make_ddim_timesteps(
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ddim_discr_method, num_ddim_timesteps, num_ddpm_timesteps, verbose=True
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):
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if ddim_discr_method == "uniform":
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c = num_ddpm_timesteps // num_ddim_timesteps
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ddim_timesteps = np.asarray(list(range(0, num_ddpm_timesteps, c)))
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elif ddim_discr_method == "quad":
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ddim_timesteps = (
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(np.linspace(0, np.sqrt(num_ddpm_timesteps * 0.8), num_ddim_timesteps)) ** 2
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).astype(int)
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else:
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raise NotImplementedError(
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f'There is no ddim discretization method called "{ddim_discr_method}"'
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)
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# assert ddim_timesteps.shape[0] == num_ddim_timesteps
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# add one to get the final alpha values right (the ones from first scale to data during sampling)
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steps_out = ddim_timesteps + 1
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if verbose:
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print(f"Selected timesteps for ddim sampler: {steps_out}")
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return steps_out
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def make_ddim_sampling_parameters(alphacums, ddim_timesteps, eta, verbose=True):
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# select alphas for computing the variance schedule
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alphas = alphacums[ddim_timesteps]
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alphas_prev = np.asarray([alphacums[0]] + alphacums[ddim_timesteps[:-1]].tolist())
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# according the the formula provided in https://arxiv.org/abs/2010.02502
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sigmas = eta * np.sqrt(
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(1 - alphas_prev) / (1 - alphas) * (1 - alphas / alphas_prev)
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)
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if verbose:
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print(
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f"Selected alphas for ddim sampler: a_t: {alphas}; a_(t-1): {alphas_prev}"
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)
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print(
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f"For the chosen value of eta, which is {eta}, "
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f"this results in the following sigma_t schedule for ddim sampler {sigmas}"
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)
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return sigmas, alphas, alphas_prev
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def betas_for_alpha_bar(num_diffusion_timesteps, alpha_bar, max_beta=0.999):
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"""
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Create a beta schedule that discretizes the given alpha_t_bar function,
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which defines the cumulative product of (1-beta) over time from t = [0,1].
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:param num_diffusion_timesteps: the number of betas to produce.
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:param alpha_bar: a lambda that takes an argument t from 0 to 1 and
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produces the cumulative product of (1-beta) up to that
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part of the diffusion process.
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:param max_beta: the maximum beta to use; use values lower than 1 to
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prevent singularities.
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"""
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betas = []
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for i in range(num_diffusion_timesteps):
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t1 = i / num_diffusion_timesteps
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t2 = (i + 1) / num_diffusion_timesteps
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betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta))
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return np.array(betas)
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def extract_into_tensor(a, t, x_shape):
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b, *_ = t.shape
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out = a.gather(-1, t)
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return out.reshape(b, *((1,) * (len(x_shape) - 1)))
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def checkpoint(func, inputs, params, flag):
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"""
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Evaluate a function without caching intermediate activations, allowing for
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reduced memory at the expense of extra compute in the backward pass.
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:param func: the function to evaluate.
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:param inputs: the argument sequence to pass to `func`.
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:param params: a sequence of parameters `func` depends on but does not
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explicitly take as arguments.
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:param flag: if False, disable gradient checkpointing.
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"""
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if flag:
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args = tuple(inputs) + tuple(params)
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return CheckpointFunction.apply(func, len(inputs), *args)
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else:
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return func(*inputs)
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class CheckpointFunction(torch.autograd.Function):
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@staticmethod
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def forward(ctx, run_function, length, *args):
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ctx.run_function = run_function
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ctx.input_tensors = list(args[:length])
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ctx.input_params = list(args[length:])
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with torch.no_grad():
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output_tensors = ctx.run_function(*ctx.input_tensors)
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return output_tensors
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@staticmethod
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def backward(ctx, *output_grads):
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ctx.input_tensors = [x.detach().requires_grad_(True) for x in ctx.input_tensors]
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with torch.enable_grad():
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# Fixes a bug where the first op in run_function modifies the
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# Tensor storage in place, which is not allowed for detach()'d
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# Tensors.
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shallow_copies = [x.view_as(x) for x in ctx.input_tensors]
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output_tensors = ctx.run_function(*shallow_copies)
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input_grads = torch.autograd.grad(
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output_tensors,
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ctx.input_tensors + ctx.input_params,
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output_grads,
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allow_unused=True,
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)
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del ctx.input_tensors
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del ctx.input_params
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del output_tensors
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return (None, None) + input_grads
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-
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def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
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"""
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Create sinusoidal timestep embeddings.
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:param timesteps: a 1-D Tensor of N indices, one per batch element.
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These may be fractional.
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:param dim: the dimension of the output.
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:param max_period: controls the minimum frequency of the embeddings.
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:return: an [N x dim] Tensor of positional embeddings.
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"""
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if not repeat_only:
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half = dim // 2
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freqs = torch.exp(
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-math.log(max_period)
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* torch.arange(start=0, end=half, dtype=torch.float32)
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/ half
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).to(device=timesteps.device)
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args = timesteps[:, None].float() * freqs[None]
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embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
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if dim % 2:
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embedding = torch.cat(
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[embedding, torch.zeros_like(embedding[:, :1])], dim=-1
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)
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else:
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embedding = repeat(timesteps, "b -> b d", d=dim)
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# import pdb; pdb.set_trace()
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return embedding
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def zero_module(module):
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"""
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Zero out the parameters of a module and return it.
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"""
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for p in module.parameters():
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p.detach().zero_()
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return module
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def scale_module(module, scale):
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"""
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Scale the parameters of a module and return it.
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"""
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for p in module.parameters():
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p.detach().mul_(scale)
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return module
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def mean_flat(tensor):
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"""
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Take the mean over all non-batch dimensions.
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"""
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return tensor.mean(dim=list(range(1, len(tensor.shape))))
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def normalization(channels):
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"""
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Make a standard normalization layer.
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:param channels: number of input channels.
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:return: an nn.Module for normalization.
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"""
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return GroupNorm32(32, channels)
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-
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# PyTorch 1.7 has SiLU, but we support PyTorch 1.5.
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class SiLU(nn.Module):
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def forward(self, x):
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return x * torch.sigmoid(x)
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-
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class GroupNorm32(nn.GroupNorm):
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def forward(self, x):
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return super().forward(x.float()).type(x.dtype)
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-
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-
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def conv_nd(dims, *args, **kwargs):
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"""
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Create a 1D, 2D, or 3D convolution module.
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"""
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if dims == 1:
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return nn.Conv1d(*args, **kwargs)
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elif dims == 2:
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return nn.Conv2d(*args, **kwargs)
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elif dims == 3:
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return nn.Conv3d(*args, **kwargs)
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raise ValueError(f"unsupported dimensions: {dims}")
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-
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def linear(*args, **kwargs):
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"""
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Create a linear module.
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"""
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return nn.Linear(*args, **kwargs)
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def avg_pool_nd(dims, *args, **kwargs):
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"""
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Create a 1D, 2D, or 3D average pooling module.
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"""
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if dims == 1:
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return nn.AvgPool1d(*args, **kwargs)
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elif dims == 2:
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return nn.AvgPool2d(*args, **kwargs)
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elif dims == 3:
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return nn.AvgPool3d(*args, **kwargs)
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raise ValueError(f"unsupported dimensions: {dims}")
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314 |
-
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315 |
-
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class HybridConditioner(nn.Module):
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def __init__(self, c_concat_config, c_crossattn_config):
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super().__init__()
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self.concat_conditioner = instantiate_from_config(c_concat_config)
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self.crossattn_conditioner = instantiate_from_config(c_crossattn_config)
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-
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def forward(self, c_concat, c_crossattn):
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c_concat = self.concat_conditioner(c_concat)
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c_crossattn = self.crossattn_conditioner(c_crossattn)
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return {"c_concat": [c_concat], "c_crossattn": [c_crossattn]}
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-
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327 |
-
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def noise_like(shape, device, repeat=False):
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repeat_noise = lambda: torch.randn((1, *shape[1:]), device=device).repeat(
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shape[0], *((1,) * (len(shape) - 1))
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)
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noise = lambda: torch.randn(shape, device=device)
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return repeat_noise() if repeat else noise()
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-
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# dummy replace
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337 |
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def convert_module_to_f16(l):
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338 |
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"""
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339 |
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Convert primitive modules to float16.
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340 |
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"""
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341 |
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if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)):
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342 |
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l.weight.data = l.weight.data.half()
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if l.bias is not None:
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l.bias.data = l.bias.data.half()
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-
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def convert_module_to_f32(l):
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"""
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Convert primitive modules to float32, undoing convert_module_to_f16().
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"""
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if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)):
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l.weight.data = l.weight.data.float()
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if l.bias is not None:
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l.bias.data = l.bias.data.float()
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# adopted from
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# https://github.com/openai/improved-diffusion/blob/main/improved_diffusion/gaussian_diffusion.py
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# and
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# https://github.com/lucidrains/denoising-diffusion-pytorch/blob/7706bdfc6f527f58d33f84b7b522e61e6e3164b3/denoising_diffusion_pytorch/denoising_diffusion_pytorch.py
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# and
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# https://github.com/openai/guided-diffusion/blob/0ba878e517b276c45d1195eb29f6f5f72659a05b/guided_diffusion/nn.py
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#
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# thanks!
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+
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+
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import os
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import math
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import torch
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import torch.nn as nn
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import numpy as np
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from einops import repeat
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import importlib
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+
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+
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def instantiate_from_config(config):
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if not "target" in config:
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if config == "__is_first_stage__":
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return None
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elif config == "__is_unconditional__":
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return None
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raise KeyError("Expected key `target` to instantiate.")
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return get_obj_from_str(config["target"])(**config.get("params", dict()))
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+
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+
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30 |
+
def get_obj_from_str(string, reload=False):
|
31 |
+
module, cls = string.rsplit(".", 1)
|
32 |
+
if reload:
|
33 |
+
module_imp = importlib.import_module(module)
|
34 |
+
importlib.reload(module_imp)
|
35 |
+
return getattr(importlib.import_module(module, package=None), cls)
|
36 |
+
|
37 |
+
|
38 |
+
def make_beta_schedule(
|
39 |
+
schedule, n_timestep, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3
|
40 |
+
):
|
41 |
+
if schedule == "linear":
|
42 |
+
betas = (
|
43 |
+
torch.linspace(
|
44 |
+
linear_start**0.5, linear_end**0.5, n_timestep, dtype=torch.float64
|
45 |
+
)
|
46 |
+
** 2
|
47 |
+
)
|
48 |
+
|
49 |
+
elif schedule == "cosine":
|
50 |
+
timesteps = (
|
51 |
+
torch.arange(n_timestep + 1, dtype=torch.float64) / n_timestep + cosine_s
|
52 |
+
)
|
53 |
+
alphas = timesteps / (1 + cosine_s) * np.pi / 2
|
54 |
+
alphas = torch.cos(alphas).pow(2)
|
55 |
+
alphas = alphas / alphas[0]
|
56 |
+
betas = 1 - alphas[1:] / alphas[:-1]
|
57 |
+
betas = np.clip(betas, a_min=0, a_max=0.999)
|
58 |
+
|
59 |
+
elif schedule == "sqrt_linear":
|
60 |
+
betas = torch.linspace(
|
61 |
+
linear_start, linear_end, n_timestep, dtype=torch.float64
|
62 |
+
)
|
63 |
+
elif schedule == "sqrt":
|
64 |
+
betas = (
|
65 |
+
torch.linspace(linear_start, linear_end, n_timestep, dtype=torch.float64)
|
66 |
+
** 0.5
|
67 |
+
)
|
68 |
+
else:
|
69 |
+
raise ValueError(f"schedule '{schedule}' unknown.")
|
70 |
+
return betas.numpy()
|
71 |
+
|
72 |
+
def enforce_zero_terminal_snr(betas):
|
73 |
+
betas = torch.tensor(betas) if not isinstance(betas, torch.Tensor) else betas
|
74 |
+
# Convert betas to alphas_bar_sqrt
|
75 |
+
alphas =1 - betas
|
76 |
+
alphas_bar = alphas.cumprod(0)
|
77 |
+
alphas_bar_sqrt = alphas_bar.sqrt()
|
78 |
+
# Store old values.
|
79 |
+
alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
|
80 |
+
alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
|
81 |
+
# Shift so last timestep is zero.
|
82 |
+
alphas_bar_sqrt -= alphas_bar_sqrt_T
|
83 |
+
# Scale so first timestep is back to old value.
|
84 |
+
alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
|
85 |
+
# Convert alphas_bar_sqrt to betas
|
86 |
+
alphas_bar = alphas_bar_sqrt ** 2
|
87 |
+
alphas = alphas_bar[1:] / alphas_bar[:-1]
|
88 |
+
alphas = torch.cat ([alphas_bar[0:1], alphas])
|
89 |
+
betas = 1 - alphas
|
90 |
+
return betas
|
91 |
+
|
92 |
+
|
93 |
+
def make_ddim_timesteps(
|
94 |
+
ddim_discr_method, num_ddim_timesteps, num_ddpm_timesteps, verbose=True
|
95 |
+
):
|
96 |
+
if ddim_discr_method == "uniform":
|
97 |
+
c = num_ddpm_timesteps // num_ddim_timesteps
|
98 |
+
ddim_timesteps = np.asarray(list(range(0, num_ddpm_timesteps, c)))
|
99 |
+
elif ddim_discr_method == "quad":
|
100 |
+
ddim_timesteps = (
|
101 |
+
(np.linspace(0, np.sqrt(num_ddpm_timesteps * 0.8), num_ddim_timesteps)) ** 2
|
102 |
+
).astype(int)
|
103 |
+
else:
|
104 |
+
raise NotImplementedError(
|
105 |
+
f'There is no ddim discretization method called "{ddim_discr_method}"'
|
106 |
+
)
|
107 |
+
|
108 |
+
# assert ddim_timesteps.shape[0] == num_ddim_timesteps
|
109 |
+
# add one to get the final alpha values right (the ones from first scale to data during sampling)
|
110 |
+
steps_out = ddim_timesteps + 1
|
111 |
+
if verbose:
|
112 |
+
print(f"Selected timesteps for ddim sampler: {steps_out}")
|
113 |
+
return steps_out
|
114 |
+
|
115 |
+
|
116 |
+
def make_ddim_sampling_parameters(alphacums, ddim_timesteps, eta, verbose=True):
|
117 |
+
# select alphas for computing the variance schedule
|
118 |
+
alphas = alphacums[ddim_timesteps]
|
119 |
+
alphas_prev = np.asarray([alphacums[0]] + alphacums[ddim_timesteps[:-1]].tolist())
|
120 |
+
|
121 |
+
# according the the formula provided in https://arxiv.org/abs/2010.02502
|
122 |
+
sigmas = eta * np.sqrt(
|
123 |
+
(1 - alphas_prev) / (1 - alphas) * (1 - alphas / alphas_prev)
|
124 |
+
)
|
125 |
+
if verbose:
|
126 |
+
print(
|
127 |
+
f"Selected alphas for ddim sampler: a_t: {alphas}; a_(t-1): {alphas_prev}"
|
128 |
+
)
|
129 |
+
print(
|
130 |
+
f"For the chosen value of eta, which is {eta}, "
|
131 |
+
f"this results in the following sigma_t schedule for ddim sampler {sigmas}"
|
132 |
+
)
|
133 |
+
return sigmas, alphas, alphas_prev
|
134 |
+
|
135 |
+
|
136 |
+
def betas_for_alpha_bar(num_diffusion_timesteps, alpha_bar, max_beta=0.999):
|
137 |
+
"""
|
138 |
+
Create a beta schedule that discretizes the given alpha_t_bar function,
|
139 |
+
which defines the cumulative product of (1-beta) over time from t = [0,1].
|
140 |
+
:param num_diffusion_timesteps: the number of betas to produce.
|
141 |
+
:param alpha_bar: a lambda that takes an argument t from 0 to 1 and
|
142 |
+
produces the cumulative product of (1-beta) up to that
|
143 |
+
part of the diffusion process.
|
144 |
+
:param max_beta: the maximum beta to use; use values lower than 1 to
|
145 |
+
prevent singularities.
|
146 |
+
"""
|
147 |
+
betas = []
|
148 |
+
for i in range(num_diffusion_timesteps):
|
149 |
+
t1 = i / num_diffusion_timesteps
|
150 |
+
t2 = (i + 1) / num_diffusion_timesteps
|
151 |
+
betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta))
|
152 |
+
return np.array(betas)
|
153 |
+
|
154 |
+
|
155 |
+
def extract_into_tensor(a, t, x_shape):
|
156 |
+
b, *_ = t.shape
|
157 |
+
out = a.gather(-1, t)
|
158 |
+
return out.reshape(b, *((1,) * (len(x_shape) - 1)))
|
159 |
+
|
160 |
+
|
161 |
+
def checkpoint(func, inputs, params, flag):
|
162 |
+
"""
|
163 |
+
Evaluate a function without caching intermediate activations, allowing for
|
164 |
+
reduced memory at the expense of extra compute in the backward pass.
|
165 |
+
:param func: the function to evaluate.
|
166 |
+
:param inputs: the argument sequence to pass to `func`.
|
167 |
+
:param params: a sequence of parameters `func` depends on but does not
|
168 |
+
explicitly take as arguments.
|
169 |
+
:param flag: if False, disable gradient checkpointing.
|
170 |
+
"""
|
171 |
+
if flag:
|
172 |
+
args = tuple(inputs) + tuple(params)
|
173 |
+
return CheckpointFunction.apply(func, len(inputs), *args)
|
174 |
+
else:
|
175 |
+
return func(*inputs)
|
176 |
+
|
177 |
+
|
178 |
+
class CheckpointFunction(torch.autograd.Function):
|
179 |
+
@staticmethod
|
180 |
+
def forward(ctx, run_function, length, *args):
|
181 |
+
ctx.run_function = run_function
|
182 |
+
ctx.input_tensors = list(args[:length])
|
183 |
+
ctx.input_params = list(args[length:])
|
184 |
+
|
185 |
+
with torch.no_grad():
|
186 |
+
output_tensors = ctx.run_function(*ctx.input_tensors)
|
187 |
+
return output_tensors
|
188 |
+
|
189 |
+
@staticmethod
|
190 |
+
def backward(ctx, *output_grads):
|
191 |
+
ctx.input_tensors = [x.detach().requires_grad_(True) for x in ctx.input_tensors]
|
192 |
+
with torch.enable_grad():
|
193 |
+
# Fixes a bug where the first op in run_function modifies the
|
194 |
+
# Tensor storage in place, which is not allowed for detach()'d
|
195 |
+
# Tensors.
|
196 |
+
shallow_copies = [x.view_as(x) for x in ctx.input_tensors]
|
197 |
+
output_tensors = ctx.run_function(*shallow_copies)
|
198 |
+
input_grads = torch.autograd.grad(
|
199 |
+
output_tensors,
|
200 |
+
ctx.input_tensors + ctx.input_params,
|
201 |
+
output_grads,
|
202 |
+
allow_unused=True,
|
203 |
+
)
|
204 |
+
del ctx.input_tensors
|
205 |
+
del ctx.input_params
|
206 |
+
del output_tensors
|
207 |
+
return (None, None) + input_grads
|
208 |
+
|
209 |
+
|
210 |
+
def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
|
211 |
+
"""
|
212 |
+
Create sinusoidal timestep embeddings.
|
213 |
+
:param timesteps: a 1-D Tensor of N indices, one per batch element.
|
214 |
+
These may be fractional.
|
215 |
+
:param dim: the dimension of the output.
|
216 |
+
:param max_period: controls the minimum frequency of the embeddings.
|
217 |
+
:return: an [N x dim] Tensor of positional embeddings.
|
218 |
+
"""
|
219 |
+
if not repeat_only:
|
220 |
+
half = dim // 2
|
221 |
+
freqs = torch.exp(
|
222 |
+
-math.log(max_period)
|
223 |
+
* torch.arange(start=0, end=half, dtype=torch.float32)
|
224 |
+
/ half
|
225 |
+
).to(device=timesteps.device)
|
226 |
+
args = timesteps[:, None].float() * freqs[None]
|
227 |
+
embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
|
228 |
+
if dim % 2:
|
229 |
+
embedding = torch.cat(
|
230 |
+
[embedding, torch.zeros_like(embedding[:, :1])], dim=-1
|
231 |
+
)
|
232 |
+
else:
|
233 |
+
embedding = repeat(timesteps, "b -> b d", d=dim)
|
234 |
+
# import pdb; pdb.set_trace()
|
235 |
+
return embedding
|
236 |
+
|
237 |
+
|
238 |
+
def zero_module(module):
|
239 |
+
"""
|
240 |
+
Zero out the parameters of a module and return it.
|
241 |
+
"""
|
242 |
+
for p in module.parameters():
|
243 |
+
p.detach().zero_()
|
244 |
+
return module
|
245 |
+
|
246 |
+
|
247 |
+
def scale_module(module, scale):
|
248 |
+
"""
|
249 |
+
Scale the parameters of a module and return it.
|
250 |
+
"""
|
251 |
+
for p in module.parameters():
|
252 |
+
p.detach().mul_(scale)
|
253 |
+
return module
|
254 |
+
|
255 |
+
|
256 |
+
def mean_flat(tensor):
|
257 |
+
"""
|
258 |
+
Take the mean over all non-batch dimensions.
|
259 |
+
"""
|
260 |
+
return tensor.mean(dim=list(range(1, len(tensor.shape))))
|
261 |
+
|
262 |
+
|
263 |
+
def normalization(channels):
|
264 |
+
"""
|
265 |
+
Make a standard normalization layer.
|
266 |
+
:param channels: number of input channels.
|
267 |
+
:return: an nn.Module for normalization.
|
268 |
+
"""
|
269 |
+
return GroupNorm32(32, channels)
|
270 |
+
|
271 |
+
|
272 |
+
# PyTorch 1.7 has SiLU, but we support PyTorch 1.5.
|
273 |
+
class SiLU(nn.Module):
|
274 |
+
def forward(self, x):
|
275 |
+
return x * torch.sigmoid(x)
|
276 |
+
|
277 |
+
|
278 |
+
class GroupNorm32(nn.GroupNorm):
|
279 |
+
def forward(self, x):
|
280 |
+
return super().forward(x.float()).type(x.dtype)
|
281 |
+
|
282 |
+
|
283 |
+
def conv_nd(dims, *args, **kwargs):
|
284 |
+
"""
|
285 |
+
Create a 1D, 2D, or 3D convolution module.
|
286 |
+
"""
|
287 |
+
if dims == 1:
|
288 |
+
return nn.Conv1d(*args, **kwargs)
|
289 |
+
elif dims == 2:
|
290 |
+
return nn.Conv2d(*args, **kwargs)
|
291 |
+
elif dims == 3:
|
292 |
+
return nn.Conv3d(*args, **kwargs)
|
293 |
+
raise ValueError(f"unsupported dimensions: {dims}")
|
294 |
+
|
295 |
+
|
296 |
+
def linear(*args, **kwargs):
|
297 |
+
"""
|
298 |
+
Create a linear module.
|
299 |
+
"""
|
300 |
+
return nn.Linear(*args, **kwargs)
|
301 |
+
|
302 |
+
|
303 |
+
def avg_pool_nd(dims, *args, **kwargs):
|
304 |
+
"""
|
305 |
+
Create a 1D, 2D, or 3D average pooling module.
|
306 |
+
"""
|
307 |
+
if dims == 1:
|
308 |
+
return nn.AvgPool1d(*args, **kwargs)
|
309 |
+
elif dims == 2:
|
310 |
+
return nn.AvgPool2d(*args, **kwargs)
|
311 |
+
elif dims == 3:
|
312 |
+
return nn.AvgPool3d(*args, **kwargs)
|
313 |
+
raise ValueError(f"unsupported dimensions: {dims}")
|
314 |
+
|
315 |
+
|
316 |
+
class HybridConditioner(nn.Module):
|
317 |
+
def __init__(self, c_concat_config, c_crossattn_config):
|
318 |
+
super().__init__()
|
319 |
+
self.concat_conditioner = instantiate_from_config(c_concat_config)
|
320 |
+
self.crossattn_conditioner = instantiate_from_config(c_crossattn_config)
|
321 |
+
|
322 |
+
def forward(self, c_concat, c_crossattn):
|
323 |
+
c_concat = self.concat_conditioner(c_concat)
|
324 |
+
c_crossattn = self.crossattn_conditioner(c_crossattn)
|
325 |
+
return {"c_concat": [c_concat], "c_crossattn": [c_crossattn]}
|
326 |
+
|
327 |
+
|
328 |
+
def noise_like(shape, device, repeat=False):
|
329 |
+
repeat_noise = lambda: torch.randn((1, *shape[1:]), device=device).repeat(
|
330 |
+
shape[0], *((1,) * (len(shape) - 1))
|
331 |
+
)
|
332 |
+
noise = lambda: torch.randn(shape, device=device)
|
333 |
+
return repeat_noise() if repeat else noise()
|
334 |
+
|
335 |
+
|
336 |
+
# dummy replace
|
337 |
+
def convert_module_to_f16(l):
|
338 |
+
"""
|
339 |
+
Convert primitive modules to float16.
|
340 |
+
"""
|
341 |
+
if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)):
|
342 |
+
l.weight.data = l.weight.data.half()
|
343 |
+
if l.bias is not None:
|
344 |
+
l.bias.data = l.bias.data.half()
|
345 |
+
|
346 |
+
def convert_module_to_f32(l):
|
347 |
+
"""
|
348 |
+
Convert primitive modules to float32, undoing convert_module_to_f16().
|
349 |
+
"""
|
350 |
+
if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)):
|
351 |
+
l.weight.data = l.weight.data.float()
|
352 |
+
if l.bias is not None:
|
353 |
+
l.bias.data = l.bias.data.float()
|