beat-sync-video-editinglisted

# Beat-Sync Video Editing ## Purpose Provide domain expertise for creating beat-synced video edits: taking a source video and an audio track, selecting clips from the video that align with the music's rhythm, and rendering the final output with FFmpeg. ## Core Concept: The EditPlan Every edit starts as an EditPlan — a JSON structure that describes which video clips to use and where in the audio to place them: ```json { "audio_start": "00:13", "audio_duration": 6.5, "clips": [ { "video_start": "00:08", "duration": 2.0, "description": "Opening shot" }, { "video_start": "00:45", "duration": 1.5, "description": "Action moment" }, { "video_start": "01:22", "duration": 3.0, "description": "Build-up" } ], "reasoning": "Matches rising intensity with beat drops" } ``` **Timestamp format:** `audio_start` and `video_start` use MM:SS strings (e.g. `"01:15"` for 1 minute 15 seconds). `audio_duration` and clip `duration` use numbers in seconds. **Critical constraints:** - `audio_start` must be valid MM:SS format, non-negative - `audio_duration` must be positive (seconds) - Every clip must have valid MM:SS `video_start` and positive `duration` (seconds) - Sum of all clip durations must equal `audio_duration` (within 0.5s tolerance) - Clip order is intentional — not necessarily chronological. Non-linear ordering creates dynamic edits. ## Workflow: From Files to Final Video ### Step 1: Generate EditPlan via Gemini Run the Gemini script to analyze video + audio