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0215

Video & Audio Generation

Video and audio generators are diffusion models with one extra ingredient: time. An image model denoises a single frame; a video model must denoise many frames that agree with each other. The fix is temporal attention — while each frame is being denoised, it attends to neighbouring frames, so a ball in frame 3 lands where frame 2 left it. Audio works the same way on a spectrogram: a picture of sound over time, denoised with the same machinery, then converted back to a waveform.

Watch six frames play as a loop. Toggle temporal attention off and each frame is denoised independently — every still looks plausible, but the ball teleports between frames and the video flickers.

frame 1frame 2frame 3frame 4frame 5frame 6Frames attend to each other: the ball follows one smooth arc.playing frame 1 / 6

Check yourself

Why can a model that makes perfect single images still produce unwatchable video?

Go deeper (free): Lilian Weng — Video diffusion models

Next: Voice Agents