remotion: Add posterize option to interpolation APIs

[JonnyBurger]

Summary

• Add a posterize option to interpolate() that floors the input to fixed-size steps before interpolation.
• Carry posterize through Visual Mode keyframe metadata and interpolation.
• Apply the same option to interpolateStyles() because it accepts InterpolateOptions.
• Document the new option and add tests for runtime behavior, validation, and keyframe parsing.

Fixes #7790

Test plan

• bun test packages/core/src/test/interpolate.test.ts packages/core/src/test/interpolate-keyframed-status.test.ts packages/studio-server/src/test/compute-sequence-props-status.test.ts packages/animation-utils/src/test/interpolate-styles.test.ts
• bun run build
• bun run formatting
• bun run stylecheck
• bun run build-docs

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
bugs	Ready	Preview, Comment	May 30, 2026 8:24am
remotion	Ready	Preview, Comment	May 30, 2026 8:24am

[pullfrog]

Reviewed changes — Added posterize option to interpolate(), interpolateStyles(), and the Studio’s keyframe prop-status pipeline. The feature quantizes the input before interpolation so animations update in discrete steps rather than every frame.

• packages/core/src/interpolate.ts — Added posterize to InterpolateOptions, an assertValidInterpolatePosterizeOption guard, and Math.floor(input / n) * n quantization before range selection and interpolation.
• packages/animation-utils — Wired posterize through interpolateStyles() using the same quantization formula.
• packages/core/src/interpolate-keyframed-status.ts — Applied frame quantization before dispatching to interpolate() or interpolateColors() for Studio-keyframed props.
• packages/studio-server — Parsed posterize from the AST options object in getInterpolationMetadata; returns computed for non-literal expressions.
• packages/docs — Documented the new option with an example and updated AvailableFrom to 4.0.470.
• Tests — Added unit tests for runtime behavior, validation, and keyframe-prop parsing.

  ^{｜ View workflow run ｜ Using Kimi K2 ｜ 𝕏}