import mlx.core as mx import numpy as np import logging log = logging.getLogger(__name__) class Config: precision: mx.Dtype = mx.bfloat16 num_train_steps = 1000 def __init__( self, num_inference_steps: int = 4, width: int = 1024, height: int = 1024, guidance: float = 4.0, ): if width % 16 != 0 or height % 16 != 0: log.warning("Width and height should be multiples of 16. Rounding down.") self.width = 16 * (height // 16) self.height = 16 * (width // 16) base_sigmas = Config.base_sigmas(num_inference_steps) self.num_inference_steps = num_inference_steps self.guidance = guidance self.sigmas = mx.concatenate([base_sigmas, mx.zeros(1)]) @staticmethod def base_sigmas(num_inference_steps): sigmas = np.linspace(1.0, 1 / num_inference_steps, num_inference_steps) sigmas = mx.array(sigmas).astype(mx.float32) return sigmas def shift_sigmas(self): y1 = 0.5 x1 = 256 m = (1.15 - y1) / (4096 - x1) b = y1 - m * x1 mu = m * self.width * self.height / 256 + b self.sigmas = mx.exp(mu) / (mx.exp(mu) + (1 / self.sigmas - 1)) self.sigmas[-1] = 0