Expected

1{
2  "tier": 2,
3  "name": "title-image-outro",
4  "composition_id": "MultiScene",
5  "description": "Three-scene composition exercising Sequence, spring, interpolate, Audio, Img, and staticFile. Title scene uses Remotion's spring (translated to GSAP back.out as an approximation). Image scene scales an Img (from staticFile) with linear interpolate. Outro scene fades text in linearly. A silent WAV plays throughout at volume 0.5.",
6  "duration_seconds": 6,
7  "fps": 30,
8  "width": 1280,
9  "height": 720,
10  "ssim_threshold": 0.95,
11  "validation": {
12    "measured_mean_ssim": 0.986,
13    "measured_min_ssim": 0.964,
14    "measured_p05_ssim": 0.967,
15    "measured_p95_ssim": 1,
16    "measured_at": "2026-09-18",
17    "measured_against": "remotion@4.0 (PNG output, BT.709) vs hyperframes@0.7.71 (sub-composition fixtures)",
18    "notes": "Spring → back.out(1.4) translation came out cleaner than expected; mean 0.986 leaves substantial headroom over 0.95."
19  },
20  "translation_notes": [
21    "spring({damping:12, stiffness:100, mass:1}) → back.out(1.4) over 0.7s. Spring overshoot+settle and back.out's overshoot+settle have similar shape; budget ~0.02 SSIM for the late-tail curvature mismatch (validated lower than predicted in spec; original notes overestimated drift).",
22    "<Sequence from durationInFrames> → a sub-composition host with data-start/data-duration in seconds; the scene's own file uses local time and explicit gsap.set(opacity, 0/1) at its boundaries to crossfade in/out cleanly",
23    "<Audio src volume> → <audio data-start data-duration data-volume>",
24    "<Img src={staticFile('x')}> → <img src='assets/x'> (`../assets/x` inside the scene sub-composition file); setup.sh copies the asset into both fixture trees",
25    "interpolate with default linear easing → ease:'none' in GSAP",
26    "Fonts again rely on system Helvetica/Arial; ~0.015 SSIM cost from AA differences"
27  ],
28  "rationale": "Threshold 0.95 sits ~0.015 below measured p05 (0.966). T2 actually validated cleaner than T1 because the lower title fontWeight (140px vs T1's 160px) shows less of the system-font fallback divergence."
29}