Sylpheed/docs/re/f3-sting-measured-no-new-stream.md

F3, the sting half, closed — no sting: zero new XMA streams across build-in and 68 s of settled pulsing

Status: ✅ measured (⟨capture⟩). Answers the dynamic half f3-title-sting-mechanism-found-not-value.md left open, using exactly the instrument and method that page named. 2026-09-12. Instrument: tools/re-capture/f3_sting_probe.py.

Method

Booted with --xma_param_probe=true (the same cvar menu-audio-cues.md used for the menu's SE census) and no pad input at all — the question is what plays automatically, not what a press triggers. Two things recorded continuously from the moment Canary's window exists, not from a threshold trigger: a glyph (green-pixel) count every ~0.5 s over the whole run, and every newly-seen XMA-PARAM log line (Xenia dedupes these itself, one per distinct stream, keyed on ptr+packet-count) stamped with wall-clock arrival time — the same "stamp on arrival" technique xma_readoff_trace.py already uses for a log with no timestamps of its own.

Positive control (R4), and it's a real one, not a synthetic one: the probe found three streams at t≈9.1 s, sharing one head but distinct packet counts and signatures — unidentified, and not this question's concern; not asserting what they are without checking — and, at t≈147.6 s, exactly two stereo streams starting together — matching f3-title-plays-bgm-102-and-103.md and bgm-two-stems.md's already-established finding that the title's BGM is two XMA stems played in sync. A probe that reproduces an already-known positive from a live run is doing its job, not merely configured correctly.

The plate's timeline, from the glyph series (not assumed)

data/f3-sting-glyph-timeseries.tsv:

t (s)	glyph	reading
0 – 147.9	0	attract movie, no plate
148.4 – 151.4	17 – 154	build-in: rising, not yet at the pulse plateau
151.8 onward	712 – 1518, cycling	settled, pulsing at its established ~2 s period

Refutation attempt, recorded either way: my first read of this was "BGM and build-in start at essentially the same moment." Checking the raw per-sample series instead of the coarse table above refutes that: the first non-zero glyph reading is 148.25 s — ~0.67 s after BGM onset (147.58 s), not simultaneous, and the values immediately after are noisy (107, 40, 0, 0, 0, 17…) rather than a clean climb, so even "build-in starts at 148.25 s" is a looser statement than "the plate is visible from about 148.4 s onward." Both clocks are anchored to the same title-appearance event, but they are not one event — worth stating precisely since a later reader chasing frame-accurate sync between title BGM and title art would otherwise inherit an overclaim.

The result

data/f3-sting-xma-param-arrivals.tsv — five distinct streams for the whole 220 s run, and none after t=147.6 s. From the plate's first visible rise (148.4 s) through 68 seconds of build-in plus fully-settled pulsing (killed at 220.1 s), the probe — which just finished proving it can catch a new stream the instant one starts — caught nothing new. No SE-range stream, no additional BGM-range one, nothing.

No sting plays when the plate appears, and none plays for over a minute of it sitting there pulsing. This is the measured answer to the half of F3 the BGM census couldn't reach: not "SE goes through a different call" (a scope limit) and not "the mechanism exists but its value is unreachable" (the static finding), but a direct negative from watching the actual sound-decode path with the game doing nothing else.

What this does not cover

• Only the boot title, no input, one run. Whether Ⓐ itself plays a confirm sting is already answered elsewhere (menu-audio-cues.md: the 0x5d6c0 wave on the title→menu transition). This page is specifically the unprompted plate-appearance question.
• The static mechanism found last iteration — a dispatch-table call chain from GamePart_Title into the generic play primitive with a non-literal cue id — is not contradicted by this. The likeliest reading, unchanged: that slot's cue value is the -1 "don't play" sentinel for this GamePart, or the emitter it configures is never triggered on this particular event. Either way, nothing plays, which is what both pages now agree on from different instruments (⟨canary-source⟩ then ⟨capture⟩).
• One run, ⟨capture⟩. A second boot repeating the null would be the standard reproducibility bar this corpus otherwise holds to; not run here given the length of this single window (68 s past first appearance) and the working positive control already in the same run.

Reach

⟨capture⟩, one boot, no input. Covers the plate's entire build-in and 68 s of settled state. Does not cover the attract-loop title (a different, harder-to-reach state per this corpus's own capture-harness history) or any input-triggered event other than the already-decoded confirm cue.