One Formula, Two Jobs: How RoPE and Timestep Embedding Are Built

RoPE and diffusion timestep embedding share the same sinusoidal skeleton and even the same frequency table. This note builds both from angular frequency up, and explains what base / max_period actually control.

The Devil in the Details: Engineering Tricks for SOTA Video Models

Theory is clean, but training is messy. This note covers 5 essential engineering tricks—from Timestep Shifting to 3D RoPE—that stabilize training and boost performance.