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V2 Tempo Beat Tracking

TempoBeatTracking_V2_Contract.json

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Phase 72.22.1.5 adds deterministic tempo detection and beat-position tracking for Maya adaptive music clips. It analyzes authored music clip metadata into BPM, beat markers, and downbeat times that can feed beat-synchronized transitions.

Source Of Truth#

  • Contract: TempoBeatTracking_V2_Contract.json
  • Runtime module: V2Audio
  • Core types: FV2TempoDetectionSourceClip, FV2DetectedBeatMarker, FV2TempoDetectionRequest, FV2TempoDetectionResult, and FV2TempoBeatTrackingCatalog
  • Builder: UV2AudioBlueprintLibrary::BuildDefaultTempoBeatTrackingCatalog
  • Validator: UV2AudioBlueprintLibrary::ValidateTempoBeatTrackingCatalog
  • Analyzer: UV2AudioBlueprintLibrary::AnalyzeTempoBeatTrackingClip
  • Registrar: UV2AudioSubsystem::RegisterTempoBeatTrackingCatalog
  • Subsystem route: UV2AudioSubsystem::AnalyzeTempoBeatTrackingClip

Clip Coverage#

The default TempoBeatTracking.V2 catalog validates the music clips needed by horizontal re-sequencing, combat music, and beat-sync transition scheduling.

Required clip ids include:

  • Music.Section.Exploration.Verse
  • Music.Section.Exploration.Chorus
  • Music.Section.Combat.Chorus
  • Music.State.Combat.Main

Beat Analysis#

FV2TempoBeatTrackingCatalog::AnalyzeClip selects a candidate BPM when supplied or falls back to the source clip's authored BPM. It converts duration to a beat grid, emits ordered BeatMarkers, and records DownbeatTimesSeconds at the configured bar interval. The accepted reason tag is Audio.TempoBeatTracking.Accepted.BpmAndBeatGrid.

The default exploration verse analysis returns 120 BPM, more than sixty beat markers over the authored clip duration, and downbeat times for bar-aligned synchronization. Combat clips can provide a measured candidate BPM such as 132 for alternate analysis passes.

Runtime Evidence#

UV2AudioConfigAsset owns the default FV2TempoBeatTrackingCatalog. UV2AudioSubsystem registers it, analyzes requested clips, stores the last accepted result, and exposes catalog registration, BPM detection, beat-position tracking, last clip id, last detected BPM, and last beat marker count through FV2AudioRuntimeSnapshot.

The catalog is rollback-cosmetic: tempo and beat-grid evidence drives audio scheduling only and does not change gameplay simulation state.

Validation Commands#

bash
python3 V2/ue/Tools/check-v2-tempo-beat-tracking.py
python3 V2/ue/Tools/check-v2-beat-synchronized-transitions.py
python3 V2/ue/Tools/check-v2-audio-module.py
python3 -m json.tool V2/ue/Content/V2/Audio/TempoBeatTracking_V2_Contract.json
python3 V2/tools/validate-v2-docs.py