import torch from comfy.ldm.modules.diffusionmodules.util import make_beta_schedule import math class EPS: def calculate_input(self, sigma, noise): sigma = sigma.view(sigma.shape[:1] + (1,) * (noise.ndim - 1)) return noise / (sigma ** 2 + self.sigma_data ** 2) ** 0.5 def calculate_denoised(self, sigma, model_output, model_input): sigma = sigma.view(sigma.shape[:1] + (1,) * (model_output.ndim - 1)) return model_input - model_output * sigma def noise_scaling(self, sigma, noise, latent_image, max_denoise=False): if max_denoise: noise = noise * torch.sqrt(1.0 + sigma ** 2.0) else: noise = noise * sigma noise += latent_image return noise class V_PREDICTION(EPS): def calculate_denoised(self, sigma, model_output, model_input): sigma = sigma.view(sigma.shape[:1] + (1,) * (model_output.ndim - 1)) return model_input * self.sigma_data ** 2 / (sigma ** 2 + self.sigma_data ** 2) - model_output * sigma * self.sigma_data / (sigma ** 2 + self.sigma_data ** 2) ** 0.5 class EDM(V_PREDICTION): def calculate_denoised(self, sigma, model_output, model_input): sigma = sigma.view(sigma.shape[:1] + (1,) * (model_output.ndim - 1)) return model_input * self.sigma_data ** 2 / (sigma ** 2 + self.sigma_data ** 2) + model_output * sigma * self.sigma_data / (sigma ** 2 + self.sigma_data ** 2) ** 0.5 class ModelSamplingDiscrete(torch.nn.Module): def __init__(self, model_config=None): super().__init__() if model_config is not None: sampling_settings = model_config.sampling_settings else: sampling_settings = {} beta_schedule = sampling_settings.get("beta_schedule", "linear") linear_start = sampling_settings.get("linear_start", 0.00085) linear_end = sampling_settings.get("linear_end", 0.012) self._register_schedule(given_betas=None, beta_schedule=beta_schedule, timesteps=1000, linear_start=linear_start, linear_end=linear_end, cosine_s=8e-3) self.sigma_data = 1.0 def _register_schedule(self, given_betas=None, beta_schedule="linear", timesteps=1000, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3): if given_betas is not None: betas = given_betas else: betas = make_beta_schedule(beta_schedule, timesteps, linear_start=linear_start, linear_end=linear_end, cosine_s=cosine_s) alphas = 1. - betas alphas_cumprod = torch.cumprod(alphas, dim=0) timesteps, = betas.shape self.num_timesteps = int(timesteps) self.linear_start = linear_start self.linear_end = linear_end # self.register_buffer('betas', torch.tensor(betas, dtype=torch.float32)) # self.register_buffer('alphas_cumprod', torch.tensor(alphas_cumprod, dtype=torch.float32)) # self.register_buffer('alphas_cumprod_prev', torch.tensor(alphas_cumprod_prev, dtype=torch.float32)) sigmas = ((1 - alphas_cumprod) / alphas_cumprod) ** 0.5 self.set_sigmas(sigmas) def set_sigmas(self, sigmas): self.register_buffer('sigmas', sigmas.float()) self.register_buffer('log_sigmas', sigmas.log().float()) @property def sigma_min(self): return self.sigmas[0] @property def sigma_max(self): return self.sigmas[-1] def timestep(self, sigma): log_sigma = sigma.log() dists = log_sigma.to(self.log_sigmas.device) - self.log_sigmas[:, None] return dists.abs().argmin(dim=0).view(sigma.shape).to(sigma.device) def sigma(self, timestep): t = torch.clamp(timestep.float().to(self.log_sigmas.device), min=0, max=(len(self.sigmas) - 1)) low_idx = t.floor().long() high_idx = t.ceil().long() w = t.frac() log_sigma = (1 - w) * self.log_sigmas[low_idx] + w * self.log_sigmas[high_idx] return log_sigma.exp().to(timestep.device) def percent_to_sigma(self, percent): if percent <= 0.0: return 999999999.9 if percent >= 1.0: return 0.0 percent = 1.0 - percent return self.sigma(torch.tensor(percent * 999.0)).item() class ModelSamplingContinuousEDM(torch.nn.Module): def __init__(self, model_config=None): super().__init__() if model_config is not None: sampling_settings = model_config.sampling_settings else: sampling_settings = {} sigma_min = sampling_settings.get("sigma_min", 0.002) sigma_max = sampling_settings.get("sigma_max", 120.0) sigma_data = sampling_settings.get("sigma_data", 1.0) self.set_parameters(sigma_min, sigma_max, sigma_data) def set_parameters(self, sigma_min, sigma_max, sigma_data): self.sigma_data = sigma_data sigmas = torch.linspace(math.log(sigma_min), math.log(sigma_max), 1000).exp() self.register_buffer('sigmas', sigmas) #for compatibility with some schedulers self.register_buffer('log_sigmas', sigmas.log()) @property def sigma_min(self): return self.sigmas[0] @property def sigma_max(self): return self.sigmas[-1] def timestep(self, sigma): return 0.25 * sigma.log() def sigma(self, timestep): return (timestep / 0.25).exp() def percent_to_sigma(self, percent): if percent <= 0.0: return 999999999.9 if percent >= 1.0: return 0.0 percent = 1.0 - percent log_sigma_min = math.log(self.sigma_min) return math.exp((math.log(self.sigma_max) - log_sigma_min) * percent + log_sigma_min) class StableCascadeSampling(ModelSamplingDiscrete): def __init__(self, model_config=None): super().__init__() if model_config is not None: sampling_settings = model_config.sampling_settings else: sampling_settings = {} self.set_parameters(sampling_settings.get("shift", 1.0)) def set_parameters(self, shift=1.0, cosine_s=8e-3): self.shift = shift self.cosine_s = torch.tensor(cosine_s) self._init_alpha_cumprod = torch.cos(self.cosine_s / (1 + self.cosine_s) * torch.pi * 0.5) ** 2 #This part is just for compatibility with some schedulers in the codebase self.num_timesteps = 10000 sigmas = torch.empty((self.num_timesteps), dtype=torch.float32) for x in range(self.num_timesteps): t = (x + 1) / self.num_timesteps sigmas[x] = self.sigma(t) self.set_sigmas(sigmas) def sigma(self, timestep): alpha_cumprod = (torch.cos((timestep + self.cosine_s) / (1 + self.cosine_s) * torch.pi * 0.5) ** 2 / self._init_alpha_cumprod) if self.shift != 1.0: var = alpha_cumprod logSNR = (var/(1-var)).log() logSNR += 2 * torch.log(1.0 / torch.tensor(self.shift)) alpha_cumprod = logSNR.sigmoid() alpha_cumprod = alpha_cumprod.clamp(0.0001, 0.9999) return ((1 - alpha_cumprod) / alpha_cumprod) ** 0.5 def timestep(self, sigma): var = 1 / ((sigma * sigma) + 1) var = var.clamp(0, 1.0) s, min_var = self.cosine_s.to(var.device), self._init_alpha_cumprod.to(var.device) t = (((var * min_var) ** 0.5).acos() / (torch.pi * 0.5)) * (1 + s) - s return t def percent_to_sigma(self, percent): if percent <= 0.0: return 999999999.9 if percent >= 1.0: return 0.0 percent = 1.0 - percent return self.sigma(torch.tensor(percent))