from collections import deque import torch import inspect import k_diffusion.sampling from modules import prompt_parser, devices, sd_samplers_common from modules.shared import opts, state import modules.shared as shared from modules.script_callbacks import CFGDenoiserParams, cfg_denoiser_callback from modules.script_callbacks import CFGDenoisedParams, cfg_denoised_callback from modules.script_callbacks import AfterCFGCallbackParams, cfg_after_cfg_callback samplers_k_diffusion = [ ('Euler a', 'sample_euler_ancestral', ['k_euler_a', 'k_euler_ancestral'], {"uses_ensd": True}), ('Euler', 'sample_euler', ['k_euler'], {}), ('LMS', 'sample_lms', ['k_lms'], {}), ('Heun', 'sample_heun', ['k_heun'], {"second_order": True}), ('DPM2', 'sample_dpm_2', ['k_dpm_2'], {'discard_next_to_last_sigma': True}), ('DPM2 a', 'sample_dpm_2_ancestral', ['k_dpm_2_a'], {'discard_next_to_last_sigma': True, "uses_ensd": True}), ('DPM++ 2S a', 'sample_dpmpp_2s_ancestral', ['k_dpmpp_2s_a'], {"uses_ensd": True, "second_order": True}), ('DPM++ 2M', 'sample_dpmpp_2m', ['k_dpmpp_2m'], {}), ('DPM++ SDE', 'sample_dpmpp_sde', ['k_dpmpp_sde'], {"second_order": True, "brownian_noise": True}), ('DPM++ 2M SDE', 'sample_dpmpp_2m_sde', ['k_dpmpp_2m_sde_ka'], {"brownian_noise": True}), ('DPM fast', 'sample_dpm_fast', ['k_dpm_fast'], {"uses_ensd": True}), ('DPM adaptive', 'sample_dpm_adaptive', ['k_dpm_ad'], {"uses_ensd": True}), ('LMS Karras', 'sample_lms', ['k_lms_ka'], {'scheduler': 'karras'}), ('DPM2 Karras', 'sample_dpm_2', ['k_dpm_2_ka'], {'scheduler': 'karras', 'discard_next_to_last_sigma': True, "uses_ensd": True, "second_order": True}), ('DPM2 a Karras', 'sample_dpm_2_ancestral', ['k_dpm_2_a_ka'], {'scheduler': 'karras', 'discard_next_to_last_sigma': True, "uses_ensd": True, "second_order": True}), ('DPM++ 2S a Karras', 'sample_dpmpp_2s_ancestral', ['k_dpmpp_2s_a_ka'], {'scheduler': 'karras', "uses_ensd": True, "second_order": True}), ('DPM++ 2M Karras', 'sample_dpmpp_2m', ['k_dpmpp_2m_ka'], {'scheduler': 'karras'}), ('DPM++ SDE Karras', 'sample_dpmpp_sde', ['k_dpmpp_sde_ka'], {'scheduler': 'karras', "second_order": True, "brownian_noise": True}), ('DPM++ 2M SDE Karras', 'sample_dpmpp_2m_sde', ['k_dpmpp_2m_sde_ka'], {'scheduler': 'karras', "brownian_noise": True}), ('Restart (new)', 'restart_sampler', ['restart'], {'scheduler': 'karras', "second_order": True}), ] @torch.no_grad() def restart_sampler(model, x, sigmas, extra_args=None, callback=None, disable=None, s_noise=1., restart_list = None): """Implements restart sampling in Restart Sampling for Improving Generative Processes (2023)""" '''Restart_list format: {min_sigma: [ restart_steps, restart_times, max_sigma]}''' '''If restart_list is None: will choose restart_list automatically, otherwise will use the given restart_list''' from tqdm.auto import trange extra_args = {} if extra_args is None else extra_args s_in = x.new_ones([x.shape[0]]) step_id = 0 from k_diffusion.sampling import to_d, get_sigmas_karras def heun_step(x, old_sigma, new_sigma, second_order = True): nonlocal step_id denoised = model(x, old_sigma * s_in, **extra_args) d = to_d(x, old_sigma, denoised) if callback is not None: callback({'x': x, 'i': step_id, 'sigma': new_sigma, 'sigma_hat': old_sigma, 'denoised': denoised}) dt = new_sigma - old_sigma if new_sigma == 0 or not second_order: # Euler method x = x + d * dt else: # Heun's method x_2 = x + d * dt denoised_2 = model(x_2, new_sigma * s_in, **extra_args) d_2 = to_d(x_2, new_sigma, denoised_2) d_prime = (d + d_2) / 2 x = x + d_prime * dt step_id += 1 return x steps = sigmas.shape[0] - 1 if restart_list is None: if steps >= 20: restart_steps = 9 restart_times = 2 if steps >= 36 else 1 sigmas = get_sigmas_karras(steps - restart_steps * restart_times, sigmas[-2].item(), sigmas[0].item(), device=sigmas.device) restart_list = {0.1: [restart_steps + 1, restart_times, 2]} else: restart_list = dict() temp_list = dict() for key, value in restart_list.items(): temp_list[int(torch.argmin(abs(sigmas - key), dim=0))] = value restart_list = temp_list for i in trange(len(sigmas) - 1, disable=disable): x = heun_step(x, sigmas[i], sigmas[i+1]) if i + 1 in restart_list: restart_steps, restart_times, restart_max = restart_list[i + 1] min_idx = i + 1 max_idx = int(torch.argmin(abs(sigmas - restart_max), dim=0)) if max_idx < min_idx: sigma_restart = get_sigmas_karras(restart_steps, sigmas[min_idx].item(), sigmas[max_idx].item(), device=sigmas.device)[:-1] # remove the zero at the end while restart_times > 0: restart_times -= 1 x = x + torch.randn_like(x) * s_noise * (sigmas[max_idx] ** 2 - sigmas[min_idx] ** 2) ** 0.5 for (old_sigma, new_sigma) in zip(sigma_restart[:-1], sigma_restart[1:]): x = heun_step(x, old_sigma, new_sigma) return x samplers_data_k_diffusion = [ sd_samplers_common.SamplerData(label, lambda model, funcname=funcname: KDiffusionSampler(funcname, model), aliases, options) for label, funcname, aliases, options in samplers_k_diffusion if (hasattr(k_diffusion.sampling, funcname) or funcname == 'restart_sampler') ] sampler_extra_params = { 'sample_euler': ['s_churn', 's_tmin', 's_tmax', 's_noise'], 'sample_heun': ['s_churn', 's_tmin', 's_tmax', 's_noise'], 'sample_dpm_2': ['s_churn', 's_tmin', 's_tmax', 's_noise'], } k_diffusion_samplers_map = {x.name: x for x in samplers_data_k_diffusion} k_diffusion_scheduler = { 'Automatic': None, 'karras': k_diffusion.sampling.get_sigmas_karras, 'exponential': k_diffusion.sampling.get_sigmas_exponential, 'polyexponential': k_diffusion.sampling.get_sigmas_polyexponential } class CFGDenoiser(torch.nn.Module): """ Classifier free guidance denoiser. A wrapper for stable diffusion model (specifically for unet) that can take a noisy picture and produce a noise-free picture using two guidances (prompts) instead of one. Originally, the second prompt is just an empty string, but we use non-empty negative prompt. """ def __init__(self, model): super().__init__() self.inner_model = model self.mask = None self.nmask = None self.init_latent = None self.step = 0 self.image_cfg_scale = None self.padded_cond_uncond = False def combine_denoised(self, x_out, conds_list, uncond, cond_scale): denoised_uncond = x_out[-uncond.shape[0]:] denoised = torch.clone(denoised_uncond) for i, conds in enumerate(conds_list): for cond_index, weight in conds: denoised[i] += (x_out[cond_index] - denoised_uncond[i]) * (weight * cond_scale) return denoised def combine_denoised_for_edit_model(self, x_out, cond_scale): out_cond, out_img_cond, out_uncond = x_out.chunk(3) denoised = out_uncond + cond_scale * (out_cond - out_img_cond) + self.image_cfg_scale * (out_img_cond - out_uncond) return denoised def forward(self, x, sigma, uncond, cond, cond_scale, s_min_uncond, image_cond): if state.interrupted or state.skipped: raise sd_samplers_common.InterruptedException # at self.image_cfg_scale == 1.0 produced results for edit model are the same as with normal sampling, # so is_edit_model is set to False to support AND composition. is_edit_model = shared.sd_model.cond_stage_key == "edit" and self.image_cfg_scale is not None and self.image_cfg_scale != 1.0 conds_list, tensor = prompt_parser.reconstruct_multicond_batch(cond, self.step) uncond = prompt_parser.reconstruct_cond_batch(uncond, self.step) assert not is_edit_model or all(len(conds) == 1 for conds in conds_list), "AND is not supported for InstructPix2Pix checkpoint (unless using Image CFG scale = 1.0)" batch_size = len(conds_list) repeats = [len(conds_list[i]) for i in range(batch_size)] if shared.sd_model.model.conditioning_key == "crossattn-adm": image_uncond = torch.zeros_like(image_cond) make_condition_dict = lambda c_crossattn, c_adm: {"c_crossattn": c_crossattn, "c_adm": c_adm} else: image_uncond = image_cond make_condition_dict = lambda c_crossattn, c_concat: {"c_crossattn": c_crossattn, "c_concat": [c_concat]} if not is_edit_model: x_in = torch.cat([torch.stack([x[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [x]) sigma_in = torch.cat([torch.stack([sigma[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [sigma]) image_cond_in = torch.cat([torch.stack([image_cond[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [image_uncond]) else: x_in = torch.cat([torch.stack([x[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [x] + [x]) sigma_in = torch.cat([torch.stack([sigma[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [sigma] + [sigma]) image_cond_in = torch.cat([torch.stack([image_cond[i] for _ in range(n)]) for i, n in enumerate(repeats)] + [image_uncond] + [torch.zeros_like(self.init_latent)]) denoiser_params = CFGDenoiserParams(x_in, image_cond_in, sigma_in, state.sampling_step, state.sampling_steps, tensor, uncond) cfg_denoiser_callback(denoiser_params) x_in = denoiser_params.x image_cond_in = denoiser_params.image_cond sigma_in = denoiser_params.sigma tensor = denoiser_params.text_cond uncond = denoiser_params.text_uncond skip_uncond = False # alternating uncond allows for higher thresholds without the quality loss normally expected from raising it if self.step % 2 and s_min_uncond > 0 and sigma[0] < s_min_uncond and not is_edit_model: skip_uncond = True x_in = x_in[:-batch_size] sigma_in = sigma_in[:-batch_size] self.padded_cond_uncond = False if shared.opts.pad_cond_uncond and tensor.shape[1] != uncond.shape[1]: empty = shared.sd_model.cond_stage_model_empty_prompt num_repeats = (tensor.shape[1] - uncond.shape[1]) // empty.shape[1] if num_repeats < 0: tensor = torch.cat([tensor, empty.repeat((tensor.shape[0], -num_repeats, 1))], axis=1) self.padded_cond_uncond = True elif num_repeats > 0: uncond = torch.cat([uncond, empty.repeat((uncond.shape[0], num_repeats, 1))], axis=1) self.padded_cond_uncond = True if tensor.shape[1] == uncond.shape[1] or skip_uncond: if is_edit_model: cond_in = torch.cat([tensor, uncond, uncond]) elif skip_uncond: cond_in = tensor else: cond_in = torch.cat([tensor, uncond]) if shared.batch_cond_uncond: x_out = self.inner_model(x_in, sigma_in, cond=make_condition_dict([cond_in], image_cond_in)) else: x_out = torch.zeros_like(x_in) for batch_offset in range(0, x_out.shape[0], batch_size): a = batch_offset b = a + batch_size x_out[a:b] = self.inner_model(x_in[a:b], sigma_in[a:b], cond=make_condition_dict([cond_in[a:b]], image_cond_in[a:b])) else: x_out = torch.zeros_like(x_in) batch_size = batch_size*2 if shared.batch_cond_uncond else batch_size for batch_offset in range(0, tensor.shape[0], batch_size): a = batch_offset b = min(a + batch_size, tensor.shape[0]) if not is_edit_model: c_crossattn = [tensor[a:b]] else: c_crossattn = torch.cat([tensor[a:b]], uncond) x_out[a:b] = self.inner_model(x_in[a:b], sigma_in[a:b], cond=make_condition_dict(c_crossattn, image_cond_in[a:b])) if not skip_uncond: x_out[-uncond.shape[0]:] = self.inner_model(x_in[-uncond.shape[0]:], sigma_in[-uncond.shape[0]:], cond=make_condition_dict([uncond], image_cond_in[-uncond.shape[0]:])) denoised_image_indexes = [x[0][0] for x in conds_list] if skip_uncond: fake_uncond = torch.cat([x_out[i:i+1] for i in denoised_image_indexes]) x_out = torch.cat([x_out, fake_uncond]) # we skipped uncond denoising, so we put cond-denoised image to where the uncond-denoised image should be denoised_params = CFGDenoisedParams(x_out, state.sampling_step, state.sampling_steps, self.inner_model) cfg_denoised_callback(denoised_params) devices.test_for_nans(x_out, "unet") if opts.live_preview_content == "Prompt": sd_samplers_common.store_latent(torch.cat([x_out[i:i+1] for i in denoised_image_indexes])) elif opts.live_preview_content == "Negative prompt": sd_samplers_common.store_latent(x_out[-uncond.shape[0]:]) if is_edit_model: denoised = self.combine_denoised_for_edit_model(x_out, cond_scale) elif skip_uncond: denoised = self.combine_denoised(x_out, conds_list, uncond, 1.0) else: denoised = self.combine_denoised(x_out, conds_list, uncond, cond_scale) if self.mask is not None: denoised = self.init_latent * self.mask + self.nmask * denoised after_cfg_callback_params = AfterCFGCallbackParams(denoised, state.sampling_step, state.sampling_steps) cfg_after_cfg_callback(after_cfg_callback_params) denoised = after_cfg_callback_params.x self.step += 1 return denoised class TorchHijack: def __init__(self, sampler_noises): # Using a deque to efficiently receive the sampler_noises in the same order as the previous index-based # implementation. self.sampler_noises = deque(sampler_noises) def __getattr__(self, item): if item == 'randn_like': return self.randn_like if hasattr(torch, item): return getattr(torch, item) raise AttributeError(f"'{type(self).__name__}' object has no attribute '{item}'") def randn_like(self, x): if self.sampler_noises: noise = self.sampler_noises.popleft() if noise.shape == x.shape: return noise if opts.randn_source == "CPU" or x.device.type == 'mps': return torch.randn_like(x, device=devices.cpu).to(x.device) else: return torch.randn_like(x) class KDiffusionSampler: def __init__(self, funcname, sd_model): denoiser = k_diffusion.external.CompVisVDenoiser if sd_model.parameterization == "v" else k_diffusion.external.CompVisDenoiser self.model_wrap = denoiser(sd_model, quantize=shared.opts.enable_quantization) self.funcname = funcname self.func = getattr(k_diffusion.sampling, self.funcname) if funcname != "restart_sampler" else restart_sampler self.extra_params = sampler_extra_params.get(funcname, []) self.model_wrap_cfg = CFGDenoiser(self.model_wrap) self.sampler_noises = None self.stop_at = None self.eta = None self.config = None # set by the function calling the constructor self.last_latent = None self.s_min_uncond = None self.conditioning_key = sd_model.model.conditioning_key def callback_state(self, d): step = d['i'] latent = d["denoised"] if opts.live_preview_content == "Combined": sd_samplers_common.store_latent(latent) self.last_latent = latent if self.stop_at is not None and step > self.stop_at: raise sd_samplers_common.InterruptedException state.sampling_step = step shared.total_tqdm.update() def launch_sampling(self, steps, func): state.sampling_steps = steps state.sampling_step = 0 try: return func() except RecursionError: print( 'Encountered RecursionError during sampling, returning last latent. ' 'rho >5 with a polyexponential scheduler may cause this error. ' 'You should try to use a smaller rho value instead.' ) return self.last_latent except sd_samplers_common.InterruptedException: return self.last_latent def number_of_needed_noises(self, p): return p.steps def initialize(self, p): self.model_wrap_cfg.mask = p.mask if hasattr(p, 'mask') else None self.model_wrap_cfg.nmask = p.nmask if hasattr(p, 'nmask') else None self.model_wrap_cfg.step = 0 self.model_wrap_cfg.image_cfg_scale = getattr(p, 'image_cfg_scale', None) self.eta = p.eta if p.eta is not None else opts.eta_ancestral self.s_min_uncond = getattr(p, 's_min_uncond', 0.0) k_diffusion.sampling.torch = TorchHijack(self.sampler_noises if self.sampler_noises is not None else []) extra_params_kwargs = {} for param_name in self.extra_params: if hasattr(p, param_name) and param_name in inspect.signature(self.func).parameters: extra_params_kwargs[param_name] = getattr(p, param_name) if 'eta' in inspect.signature(self.func).parameters: if self.eta != 1.0: p.extra_generation_params["Eta"] = self.eta extra_params_kwargs['eta'] = self.eta return extra_params_kwargs def get_sigmas(self, p, steps): discard_next_to_last_sigma = self.config is not None and self.config.options.get('discard_next_to_last_sigma', False) if opts.always_discard_next_to_last_sigma and not discard_next_to_last_sigma: discard_next_to_last_sigma = True p.extra_generation_params["Discard penultimate sigma"] = True steps += 1 if discard_next_to_last_sigma else 0 if p.sampler_noise_scheduler_override: sigmas = p.sampler_noise_scheduler_override(steps) elif opts.k_sched_type != "Automatic": m_sigma_min, m_sigma_max = (self.model_wrap.sigmas[0].item(), self.model_wrap.sigmas[-1].item()) sigma_min, sigma_max = (0.1, 10) if opts.use_old_karras_scheduler_sigmas else (m_sigma_min, m_sigma_max) sigmas_kwargs = { 'sigma_min': sigma_min, 'sigma_max': sigma_max, } sigmas_func = k_diffusion_scheduler[opts.k_sched_type] p.extra_generation_params["Schedule type"] = opts.k_sched_type if opts.sigma_min != m_sigma_min and opts.sigma_min != 0: sigmas_kwargs['sigma_min'] = opts.sigma_min p.extra_generation_params["Schedule min sigma"] = opts.sigma_min if opts.sigma_max != m_sigma_max and opts.sigma_max != 0: sigmas_kwargs['sigma_max'] = opts.sigma_max p.extra_generation_params["Schedule max sigma"] = opts.sigma_max default_rho = 1. if opts.k_sched_type == "polyexponential" else 7. if opts.k_sched_type != 'exponential' and opts.rho != 0 and opts.rho != default_rho: sigmas_kwargs['rho'] = opts.rho p.extra_generation_params["Schedule rho"] = opts.rho sigmas = sigmas_func(n=steps, **sigmas_kwargs, device=shared.device) elif self.config is not None and self.config.options.get('scheduler', None) == 'karras': sigma_min, sigma_max = (0.1, 10) if opts.use_old_karras_scheduler_sigmas else (self.model_wrap.sigmas[0].item(), self.model_wrap.sigmas[-1].item()) sigmas = k_diffusion.sampling.get_sigmas_karras(n=steps, sigma_min=sigma_min, sigma_max=sigma_max, device=shared.device) else: sigmas = self.model_wrap.get_sigmas(steps) if discard_next_to_last_sigma: sigmas = torch.cat([sigmas[:-2], sigmas[-1:]]) return sigmas def create_noise_sampler(self, x, sigmas, p): """For DPM++ SDE: manually create noise sampler to enable deterministic results across different batch sizes""" if shared.opts.no_dpmpp_sde_batch_determinism: return None from k_diffusion.sampling import BrownianTreeNoiseSampler sigma_min, sigma_max = sigmas[sigmas > 0].min(), sigmas.max() current_iter_seeds = p.all_seeds[p.iteration * p.batch_size:(p.iteration + 1) * p.batch_size] return BrownianTreeNoiseSampler(x, sigma_min, sigma_max, seed=current_iter_seeds) def sample_img2img(self, p, x, noise, conditioning, unconditional_conditioning, steps=None, image_conditioning=None): steps, t_enc = sd_samplers_common.setup_img2img_steps(p, steps) sigmas = self.get_sigmas(p, steps) sigma_sched = sigmas[steps - t_enc - 1:] xi = x + noise * sigma_sched[0] extra_params_kwargs = self.initialize(p) parameters = inspect.signature(self.func).parameters if 'sigma_min' in parameters: ## last sigma is zero which isn't allowed by DPM Fast & Adaptive so taking value before last extra_params_kwargs['sigma_min'] = sigma_sched[-2] if 'sigma_max' in parameters: extra_params_kwargs['sigma_max'] = sigma_sched[0] if 'n' in parameters: extra_params_kwargs['n'] = len(sigma_sched) - 1 if 'sigma_sched' in parameters: extra_params_kwargs['sigma_sched'] = sigma_sched if 'sigmas' in parameters: extra_params_kwargs['sigmas'] = sigma_sched if self.config.options.get('brownian_noise', False): noise_sampler = self.create_noise_sampler(x, sigmas, p) extra_params_kwargs['noise_sampler'] = noise_sampler self.model_wrap_cfg.init_latent = x self.last_latent = x extra_args = { 'cond': conditioning, 'image_cond': image_conditioning, 'uncond': unconditional_conditioning, 'cond_scale': p.cfg_scale, 's_min_uncond': self.s_min_uncond } samples = self.launch_sampling(t_enc + 1, lambda: self.func(self.model_wrap_cfg, xi, extra_args=extra_args, disable=False, callback=self.callback_state, **extra_params_kwargs)) if self.model_wrap_cfg.padded_cond_uncond: p.extra_generation_params["Pad conds"] = True return samples def sample(self, p, x, conditioning, unconditional_conditioning, steps=None, image_conditioning=None): steps = steps or p.steps sigmas = self.get_sigmas(p, steps) x = x * sigmas[0] extra_params_kwargs = self.initialize(p) parameters = inspect.signature(self.func).parameters if 'sigma_min' in parameters: extra_params_kwargs['sigma_min'] = self.model_wrap.sigmas[0].item() extra_params_kwargs['sigma_max'] = self.model_wrap.sigmas[-1].item() if 'n' in parameters: extra_params_kwargs['n'] = steps else: extra_params_kwargs['sigmas'] = sigmas if self.config.options.get('brownian_noise', False): noise_sampler = self.create_noise_sampler(x, sigmas, p) extra_params_kwargs['noise_sampler'] = noise_sampler self.last_latent = x samples = self.launch_sampling(steps, lambda: self.func(self.model_wrap_cfg, x, extra_args={ 'cond': conditioning, 'image_cond': image_conditioning, 'uncond': unconditional_conditioning, 'cond_scale': p.cfg_scale, 's_min_uncond': self.s_min_uncond }, disable=False, callback=self.callback_state, **extra_params_kwargs)) if self.model_wrap_cfg.padded_cond_uncond: p.extra_generation_params["Pad conds"] = True return samples