Glossary

Project and timeline

• Project — canonical persistent JSON describing what to edit.
• Sequence — an output timeline with canvas, time, audio, and ordered tracks.
• Track — ordered container for compatible Items.
• Item — timed visual, audio, caption, transition, or nested content.
• Asset — persistent media identity, separate from runtime bytes.
• Representation — original, proxy, or compatible rendition of an Asset.
• Link Group — Items intended to participate in linked editing.
• Marker — non-rendering time annotation.

Time and editing

• Timeline time — placement in a Sequence, stored as integer microseconds.
• Source time — position inside original media.
• Time map — mapping from Item-local/timeline time to source evaluation.
• Revision — monotonically increasing committed Project version.
• Transaction — atomic candidate edit validated before commit.
• History group — several interaction updates represented by one undo entry.

Execution

• Session — runtime owner for Project, editing, preview, playback, export, and diagnostics.
• Render IR — immutable resolved audio/visual execution graph shared by preview and export.
• Preview — latency-oriented evaluation at requested timeline time.
• Player — timed playback using audio clock when audio is active.
• Capability report — usable environment/backend/config observations.
• Preflight — exact validation of a requested operation before starting it.

Media, Materials, and export

• Media Provider — runtime binding from Asset ID to bytes/index/decode.
• SampleIndex — container-derived sample timing/keyframe/byte-location data.
• Material Definition — reusable typed visual behavior and metadata.
• Material Instance — Project-owned parameter/resource/input bindings to a Definition.
• Material Package — deterministic manifest and payload with integrity identity.
• Sink — caller-owned output destination.
• Export profile — stable format intent such as mp4-h264-aac.
• Remote provider — application service adapter for durable server-side rendering.