Skip to content
Learn Motion
ExploreHow it worksMembership
Log in
Learn Motion

How Text-to-Video AI Works Under the Hood

1From Prompt to Conditioning Signal2Latent Diffusion: Generating Video in Compressed Space3Spatio-Temporal Attention: Keeping Frames Consistent4Where the Pipeline Breaks: Failure Modes and Their Causes
From Prompt to Conditioning Signal

How Conditioning Enters the Generator

4 / 4
So how does that sequence actually steer the video? It enters through cross-attention. Picture the spatial grid of the video as a set of queries, and the prompt tokens as keys and values.
0:00 / 0:00

The conditioning embeddings reach the generator through cross-attention. In cross-attention, the spatial positions of the video latent act as queries, while the prompt token embeddings act as keys and values. Each position computes how strongly it matches each token and pulls in a weighted mixture. That is why different regions of the frame can attend to different words: the region containing the boat queries "boat" most strongly, while the region containing rain queries "rainy". The prompt is therefore a control signal applied at every generation step, not a key that retrieves a stored video.

References

  1. [1]Attention Is All You Need (Vaswani et al., 2017)arxiv.org
  2. [2]High-Resolution Image Synthesis with Latent Diffusion Models (Rombach et al., 2022)arxiv.org
Previous4 / 4Next

Learn Motion

Generate a course. Learn it properly.

Operated by Wuhan Daoyin Technology Co., Ltd.

Contact: [email protected]
Privacy PolicyTerms of Service

© 2026 Learn Motion