{
 "format": "sylpheed.timing/1",
 "keyframe_units_per_second": 60,
 "why": [
  "HANDOFF Q1. The disc says a keyframe is at `t=30`; it does not say what a",
  "`t` is. The unit was MEASURED off the running game, not decoded: a declared",
  "15-unit fade lands on round(255*k/15) for all seven of its samples with k",
  "stepping 2,4,6,8,10,12,14 on seven consecutive submitted frames -- so 2",
  "units per rendered frame -- and the idle title presents at 28.3-28.8 fps,",
  "a 30 Hz game, giving 60 units per second. A second line agrees: the",
  "transition quad is declared black for 12 units, and a capture measured the",
  "pure-black plateau at 0.17-0.23 s, where 12/60 = 0.20 s.",
  "",
  "Expressed as units-per-second rather than seconds-per-unit so the value is",
  "exact rather than a repeating decimal a reader has to recognise.",
  "",
  "DELETE THIS FILE when a field on the disc is found that states the unit.",
  "Nothing here is on the disc."
 ],
 "kind": "measured",
 "source": "/reborn docs/port/HANDOFF.md Q1, docs/re/ui-keyframe-time-unit.md",
 "ramp": "linear",
 "ramp_why": [
  "Also HANDOFF Q1, and part of the same measurement: the fade lands on the",
  "linear value at every one of the seven sampled frames, so there is no ease."
 ],
 "exit_ramp_seconds": 0.4,
 "exit_ramp_why": [
  "HANDOFF Q7 + the RE agent's 2026-08-29 answer. MEASURED, not on the disc.",
  "",
  "Every element of a screen ends on exactly ONE untimed keyframe, so there is",
  "exactly one unknown duration per screen -- the ramp INTO that final keyframe.",
  "This is that duration. ~0.4 s, which is 24 units at 60 units/s.",
  "",
  "The alternative readings were tested and refuted. It is not a black quad laid",
  "over a frozen screen: under that model a black rect scales every region by the",
  "same 1-alpha, so the button-region / background-region brightness RATIO would",
  "be constant through the fade. Measured on the RE agent's filmstrip it falls",
  "6.495 -> 5.574 -> 3.105 -> 2.125 -> 1.935, a 3.4x monotonic drop. The screen",
  "itself plays out: pteff00.prm ramps to opaque black while the button labels,",
  "ptmsg, pteff10 and pteff12 all ramp to transparent, and ptframe1/2 hold.",
  "",
  "REACH, quoted from the RE agent rather than smoothed over: the filmstrip is",
  "downsampled and the button region contains some background, so this pins the",
  "DIRECTION, not 0.4 s to +/-0.05 s, and it is one transition pair. Treat the",
  "number as approximate and the model as established."
 ],
 "exit_ramp_units": 24,
 "dwell_seconds": null,
 "dwell_why": [
  "NOT SET, and not needed. A screen's dwell is its OWN keyframe group: the",
  "publisher wordmark reaches its hold at t=235 (3.92 s) and the developer logos",
  "at t=190 (3.17 s), both read from the disc. Adding a hold on top of that would",
  "be inventing a number nobody measured, so the sequencer holds for zero extra",
  "time and the pacing you see is the disc's own.",
  "",
  "If a capture ever times the real boot, this is where that number goes."
 ],
 "looping_focus_records": {
  "_": [
   "WHICH focus records the port draws unconditionally, and loops. CHOSEN, and",
   "deliberately a LOOKUP rather than a rule -- delete an entry the day the disc",
   "or a capture states it.",
   "",
   "THE PRESS (A) PLATE GLOWS AND PULSES. Measured on the running game:",
   "`ptbtn00f`, the plate's focus record, ramps alpha 0x00->0x50 and back, and",
   "its period was timed four times at 2.12 / 2.19 / 2.34 / 2.31 s. You cannot",
   "measure a period unless the thing repeats, so THAT IT LOOPS IS MEASURED. The",
   "port drew nothing at all here, because press_start has no `buttons` and",
   "nothing is focused.",
   "",
   "WHY A LOOKUP AND NOT A RULE, which is the part worth keeping. The spinning",
   "ring is a RULE in the renderer (`spin_period_units`) because it has a",
   "disc-wide check: 16 of 212 elements match its shape and all 16 are focus",
   "rings, zero false positives. The obvious rule for a pulse -- a group whose",
   "keyframes vary only in alpha and whose first and last alpha are equal -- was",
   "CENSUSED BEFORE BEING WRITTEN and it fails: 82 OF 212 ELEMENTS MATCH,",
   "including ptcopyright, palogo_sqex, ptmsg and every _eff fade-in. A renderer",
   "rule on that shape would make the copyright notice pulse.",
   "",
   "Narrowing to focus records leaves exactly ONE distinct element (ptbtn00f,",
   "plus its JP twin), and a rule justified by n=1 is a special case wearing a",
   "rule's clothes. So it is written here, per element, by name."
  ],
  "press_start/ptbtn00": {
   "record_element": "ptbtn00f",
   "period_units": 129,
   "kind": "chosen",
   "why": [
    "129 units = the element's own group under the port's existing timing model:",
    "its last timed keyframe is t=105 and the final untimed keyframe is reached",
    "`exit_ramp_units` (24) later. NO NEW CONSTANT is introduced -- 24 is the",
    "same authored value every other element's exit already uses.",
    "",
    "129 units is 2.150 s at 60 units/s, and 2.295 s at the ~28.1 fps that",
    "emulator presents (56.2 units/s), against measurements of 2.12 / 2.19 /",
    "2.34 / 2.31 s. It sits inside that spread at either rate.",
    "",
    "IT IS A CHOICE, and here is the alternative the data CANNOT rule out: the",
    "cycle could restart at the group's first keyframe (t=6) rather than at 0,",
    "giving 123 units = 2.050 s / 2.189 s at emulator rate. That ALSO sits",
    "inside the measured spread. Nothing available separates them, so t=0 is",
    "taken because it is where every other group in this port starts -- which is",
    "consistency, not evidence.",
    "",
    "A fifth reading exists and is NOT averaged in: the Decoder re-picked its",
    "troughs and got 2.628 s, having previously reported 2.369 from the same",
    "run. It withdrew the estimate as too weak to resolve better than ~7%, so it",
    "is recorded here and not used.",
    "",
    "WHAT DELETES THIS ENTRY: a capture that times the pulse against a landmark",
    "in the same frame, or a loop flag decoded on the disc."
   ]
  }
 }
}