diff --git a/modules/sd_models.py b/modules/sd_models.py index 2c0457715..fbd53adba 100644 --- a/modules/sd_models.py +++ b/modules/sd_models.py @@ -15,6 +15,7 @@ from ldm.util import instantiate_from_config from modules import paths, shared, modelloader, devices, script_callbacks, sd_vae, sd_disable_initialization, errors, hashes, sd_models_config, sd_unet, sd_models_xl, cache, extra_networks, processing, lowvram, sd_hijack, patches from modules.timer import Timer +from modules.shared import opts import tomesd import numpy as np @@ -549,6 +550,36 @@ def repair_config(sd_config): karlo_path = os.path.join(paths.models_path, 'karlo') sd_config.model.params.noise_aug_config.params.clip_stats_path = sd_config.model.params.noise_aug_config.params.clip_stats_path.replace("checkpoints/karlo_models", karlo_path) +def apply_alpha_schedule_override(sd_model, p=None): + def rescale_zero_terminal_snr_abar(alphas_cumprod): + alphas_bar_sqrt = alphas_cumprod.sqrt() + + # Store old values. + alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone() + alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone() + + # Shift so the last timestep is zero. + alphas_bar_sqrt -= (alphas_bar_sqrt_T) + + # Scale so the first timestep is back to the old value. + alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T) + + # Convert alphas_bar_sqrt to betas + alphas_bar = alphas_bar_sqrt**2 # Revert sqrt + alphas_bar[-1] = 4.8973451890853435e-08 + return alphas_bar + + if hasattr(sd_model, 'alphas_cumprod') and hasattr(sd_model, 'alphas_cumprod_original'): + sd_model.alphas_cumprod = sd_model.alphas_cumprod_original.to(shared.device) + + if opts.use_downcasted_alpha_bar: + if p is not None: + p.extra_generation_params['Downcast alphas_cumprod'] = opts.use_downcasted_alpha_bar + sd_model.alphas_cumprod = sd_model.alphas_cumprod.half().to(shared.device) + if opts.sd_noise_schedule == "Zero Terminal SNR": + if p is not None: + p.extra_generation_params['Noise Schedule'] = opts.sd_noise_schedule + sd_model.alphas_cumprod = rescale_zero_terminal_snr_abar(sd_model.alphas_cumprod).to(shared.device) sd1_clip_weight = 'cond_stage_model.transformer.text_model.embeddings.token_embedding.weight' sd2_clip_weight = 'cond_stage_model.model.transformer.resblocks.0.attn.in_proj_weight' @@ -812,6 +843,7 @@ def reload_model_weights(sd_model=None, info=None, forced_reload=False): sd_model = reuse_model_from_already_loaded(sd_model, checkpoint_info, timer) if not forced_reload and sd_model is not None and sd_model.sd_checkpoint_info.filename == checkpoint_info.filename: + apply_alpha_schedule_override(sd_model) return sd_model if sd_model is not None: