{
  "tier": 1,
  "name": "title-card-fade",
  "composition_id": "TitleCard",
  "description": "Solid black background, single 'HELLO' element fades in 0-0.5s, holds 0.5-2.5s, fades out 2.5-3.0s. Tests the most basic Remotion → HyperFrames translation: a single AbsoluteFill, a single useCurrentFrame-driven interpolate, no audio, no media, no custom React components.",
  "duration_seconds": 3,
  "fps": 30,
  "width": 1280,
  "height": 720,
  "ssim_threshold": 0.95,
  "validation": {
    "measured_mean_ssim": 0.974,
    "measured_min_ssim": 0.972,
    "measured_p05_ssim": 0.972,
    "measured_p95_ssim": 0.983,
    "measured_at": "2026-04-27",
    "measured_against": "remotion@4.0 (PNG output, BT.709) vs hyperframes@0.4.15-alpha.1"
  },
  "translation_notes": [
    "Remotion: AbsoluteFill → HF: position:absolute;inset:0 div",
    "Remotion: interpolate(frame, [0,15,75,90], [0,1,1,0]) at fps=30 → HF: paused GSAP timeline with three keyframed tweens at 0s, 0.5s, 2.5s with ease:'none' (linear matches Remotion's default linear interpolation)",
    "No fonts loaded; both renderers use system Helvetica/Arial fallback. The Linux fallback diverges between Remotion's bundled Chromium and HyperFrames' chrome-headless-shell — same fontWeight:800 renders perceptibly bolder in HF. This costs ~0.025 mean SSIM and is the dominant non-translation noise floor.",
    "Remotion config must use setVideoImageFormat('png') + setColorSpace('bt709'); the JPEG default writes yuvj420p (full-range) which costs ~0.05 SSIM vs HF's yuv420p (limited-range)."
  ],
  "rationale": "Threshold 0.95 sits ~0.02 below measured p05. A real translation regression (wrong easing, wrong durations) drops mean SSIM by 0.05+. Encoder/font drift between CI runs is bounded at ~0.01."
}
