# BRIEFING — 2026-10-09T07:53:00Z

## Mission
Investigate and design the assembly pipeline, export hierarchy, and E2E verification test suite for Milestone M4 (Assembly, Exports & E2E Testing Strategy) covering all 10 Scenes of Ep01 (140 shots = 23m20s feature cut).

## 🔒 My Identity
- Archetype: explorer
- Roles: investigator, analyzer, reporter
- Working directory: c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2
- Original parent: f9992164-c0e4-4f7d-ba4a-25a83a4436bf
- Milestone: M4 Pipeline Integration & Generation Trigger
- Milestone (New): M4 Assembly, Exports & E2E Testing Strategy (Ep01 Scenes 01 to 10)
- Current dispatcher: 97faf5e5-a830-491c-b78c-2af12175badf

## 🔒 Key Constraints
- Read-only investigation — do NOT implement
- Work only in own folder (`.agents/teamwork/explorer_m4_2`)
- Follow 5-component handoff protocol
- Anti-dilution project: KieuStory
- Zero permanent deletion of IP evidence
- FFmpeg filter_complex concat strictly required (OpenCV concat strictly prohibited)
- EBU R128 (-14 LUFS, TP -1.0 dBTP) audio mastering compliance

## Current Parent
- Conversation ID: 97faf5e5-a830-491c-b78c-2af12175badf
- Updated: 2026-10-09T07:45:04Z

## Investigation State
- **Explored paths**:
  * `05_Production_Pipeline/audio_continuity_engine.py` (inspected 4-stem mixing, two-pass loudnorm, micro-crossfade, silence fallback).
  * `05_Production_Pipeline/production_orchestrator.py` (inspected `concat_scene_shots`, `master_scene_audio`, versioning).
  * `05_Production_Pipeline/assemble_ep01_feature.py` (identified hardcoded 15 scenes and missing `_master_audio` candidate resolution).
  * `05_Production_Pipeline/antigravity_critic_gate.py` (inspected `evaluate_scene_gate`, `VideoCriticVerdict`).
  * `05_Production_Pipeline/episode_manager.py` (inspected episode status reporting).
  * `04_Assets/videos/`, `06_Exports/`, `04_Assets/archive/ep01_legacy_v1/`.
  * `episodes/ep01/prompts/muse_prompts.json` (mapped all 10 scenes, verified 140 shots total).
  * `tests/test_production_pipeline_m3.py`, `tests/test_adversarial_m3_audio_engine.py`, `tests/test_critic_gate.py`.
- **Key findings**:
  1. Ep01 Scenes 01 to 10 comprise exactly 140 shots (21+15+15+12+27+14+8+8+6+14 = 140 shots = 23m20s).
  2. All 184 legacy Ep01 video files were safely migrated to `04_Assets/archive/ep01_legacy_v1/`.
  3. `assemble_ep01_feature.py` hardcodes 15 scenes and missing `*_master_audio` scanning. Formulated drop-in recipe to support 10 scenes (`--scenes 10`) and `ep01_full_feature_master_v1.mp4`.
  4. `production_orchestrator.py` defaults to `_cinematic_master` rather than `_master_audio`. Formulated recipe for naming consistency.
  5. Tested synthetic media generation with FFmpeg `lavfi` (`color` + `sine`), achieving 0.43s clip creation and 0.24s concat with exact `-14.01 LUFS` normalization.
  6. Designed 5 test groups in `tests/test_production_pipeline_m4.py` running in `< 10s`.
- **Unexplored areas**: None (investigation complete).

## Key Decisions Made
- Fully specified export naming hierarchy: raw scene masters in `04_Assets/videos/ep01_scene{NN}_master_v1.mp4`, audio masters in `06_Exports/ep01_scene{NN}_master_audio_v1.mp4`, and feature cut in `06_Exports/ep01_full_feature_master_v1.mp4`.
- Authored technical blueprint in `m4_assembly_test_blueprint.md`.
- Formulated complete test implementation for `tests/test_production_pipeline_m4.py`.

## Artifact Index
- `c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2\DISPATCH.md` — Dispatch log
- `c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2\BRIEFING.md` — Working memory
- `c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2\progress.md` — Liveness heartbeat
- `c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2\m4_assembly_test_blueprint.md` — Assembly & testing blueprint
- `c:\Projects\KieuStory\.agents\teamwork\explorer_m4_2\handoff.md` — 5-component handoff report