lacing.adapters.otio#

OpenTimelineIO (OTIO) adapter — NLE / video editing interchange.

OTIO is the Academy Software Foundation’s standard for video timeline interchange. Per OSS-DOC, lacing’s RationalTime design is directly inspired by OTIO’s — this adapter is the place where that parity pays off.

Mapping#

OTIO ↔ lacing Timeline ↔ a project (one OTIO file = one store) Track ↔ a tier (track name becomes tier name) Clip ↔ Annotation (interval = source_range

offset onto the track timeline)

Clip.media_reference.target_url ↔ MediaRef.asset_id Marker (on Track or Clip) ↔ point Annotation Clip.metadata / Marker.metadata ↔ body['otio_metadata'] MarkerColor ↔ body['color']

Time#

OTIO RationalTime maps to lacing RationalTime directly — same (value, rate) shape. We re-quantize to the requested project rate on load if needed; raises LossyTimeConversionError on inexact conversions.

Lossy on dump#

  • Per-annotation provenance (was_attributed_to, was_derived_from) is dropped — OTIO carries no per-clip annotator field.

  • Confidence is dropped — OTIO has no equivalent.

  • Track effects + transitions are dropped — out of lacing’s scope.

  • Clips are emitted with an ExternalReference whose target_url is the MediaRef.asset_id.

Spec: https://opentimelineio.readthedocs.io/

Functions

dump(store[, target, name])

Serialize store as an OTIO file.

load(source, *[, rate, asset_id, attribution])

Load an OTIO file/JSON into a MemoryStore.
lacing.adapters.otio.dump(store, target=None, *, name='lacing', **_kwargs)[source]#

Serialize store as an OTIO file.

Each tier becomes one Track. Annotations whose body has kind=='marker' are emitted as Marker``s on the track at their interval start. Annotations whose body has ``kind=='clip' (or no explicit kind) become Clips with ExternalReference to the asset_id and source_range matching the lacing interval.

Note

lacing intervals are absolute positions; OTIO clips are sequential within a track. We sort + place clips back-to-back per tier; gaps between intervals become explicit Gap items.

Return type:

bytes | None

lacing.adapters.otio.load(source, *, rate=24000, asset_id=None, attribution='anonymous', **_kwargs)[source]#

Load an OTIO file/JSON into a MemoryStore.

Each track becomes a tier. Each clip becomes one Annotation with MediaRef pointing at the clip’s media reference (or the asset_id override). Markers on the timeline, track, or clip become point Annotation``s on a ``markers tier.

Parameters:

  • source (str | bytes | PathLike) – Path or bytes containing OTIO JSON.

  • rate (int) – Quantization rate.

  • asset_id (str | None) – Override media reference for every clip. None = use each clip’s own media_reference.target_url.

  • attribution (str) – Provenance.was_attributed_to value.

Return type:

IntervalAnnotationStore