The parity doc and the capability model had drifted from the players in both
directions, and nothing failed when they did. Auditing all four players against
their shipped sources turned up three controls a customer can press today that
change nothing, and a set of baselines that were partly too generous and partly
too stingy.
The three dead controls:
- The volume slider works on Android only. The dashboard sends set_volume as
{ level: 0..1 }; the web player reads payload.value and Tizen reads
payload.value ?? payload.volume, so on both the number is undefined and the
handler quietly declines. Three complete, working volume implementations
that cannot be driven. The fix is one line in each player and belongs to
those files; audio.volume is out of the web and brightsign baselines until
it lands, held there by a biconditional test that fails the moment a player
starts reading `level`.
- Every #161 Tier-2 command was refused for the entire fleet. lock_now,
power_menu, status_bar, block_uninstall and unblock_uninstall were gated on
system.device_owner, which no player declares and no baseline grants, so
supports() was false everywhere -- including on the device-owner panels the
feature was built for. The dashboard still drew the buttons because it also
gates on device.tier === 2. Fixed here: those five now accept
system.device_owner OR system.kiosk, which PlayerCapabilities.kt declares
under `if (isOwner)` and nothing else, and which no non-Android player
declares. Android should declare system.device_owner and retire the
stand-in.
- enable_system_capture required the capability it creates. It raises the
MediaProjection consent dialog -- the way a panel GAINS capture -- and was
gated on remote.screenshot, so the only panel that needs it was the one
panel that could not be sent it. Now ungated. The dashboard still hides the
button behind the same check; that half is a frontend change.
The baselines describe what an un-updated fielded display can do, and since
v1.9.29 is the first build in which any player declares anything, that means
v1.9.28. Every entry is now justified against `git show v1.9.28:<source>`:
- android loses display.power (v1.9.28 answers screen_on with a logged no-op,
so the ON half is dead on every fielded panel and one capability renders
both buttons) and system.reboot (owner-only; off-owner it paints an
accessibility power dialog over the signage). Scheduled reboots now skip
undeclared Android panels rather than logging a reboot that never happened,
which is the reason that gate exists.
- tizen gains display.power: v1.9.28 implements both halves with no signing
and no panel API, so withholding it hid a working control.
- brightsign loses audio.volume, display.power, system.reboot,
system.restart_player and offline.cache. All need a host bridge the unit is
not known to have, and restart_player without one is the page reload that
darkened a panel on 2026-07-28.
Also found, not fixed here because the files belong to others:
st-bridge.js computeCapabilities() is dead code -- nothing calls BS.capabilities()
-- and its 199 lines of passing tests constrain nothing a BrightSign actually
declares; the two disagree on six capabilities and the bridge is right about
most of them. BrightSign's "Force update" button is dead. PlayerCapabilities.kt
under-declares display.brightness.
The new test reads the player sources rather than the table: a dead-button rule
(every gated command has a branch somewhere), an unreachable-capability rule
(which would have caught system.device_owner), and biconditionals so a fix in a
player fails the test until the baseline follows. Claims that need hardware --
CEC reaching a display, a widget being allowed a service worker, SyncManager
holding frame lock -- are marked unverifiable in the document instead of
asserted.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uaeo9MvzKoyXuN6ZsbhtkL
Two more corrections from the cross-player audit, both mine.
audio.volume removed: a fielded Tizen panel has NO set_volume handler — the
command falls through to "unknown command" and the dashboard slider does
nothing. One of the platform branches adds a handler, and those panels will
declare the capability for themselves once they run it; the baseline exists to
describe an un-updated display, so it must not borrow credit from a build that
has not shipped.
remote.screenshot and remote.stream added: both really are implemented in the
shipped player (captureAndSend, startStreaming). Omitting them would have hidden
working controls on every legacy Tizen display the moment gating went live —
the opposite failure, and the more damaging one.
That asymmetry is the thing to hold on to: over-claiming shows a dead button,
under-claiming removes a working one, and only reading the shipped code tells
you which you are doing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uaeo9MvzKoyXuN6ZsbhtkL
The platform audit caught my own contract lying. I gave the Tizen baseline
offline.cache; Tizen caches only the playlist JSON (st_payload_cache, in
localStorage) and has no service worker and no media cache, so the bytes still
come from the network and an outage leaves a panel holding a playlist it cannot
play.
That is exactly the claim this model exists to prevent, made by the model itself,
and it would have applied to every legacy Tizen panel — the ones that declare
nothing and depend entirely on the baseline being honest.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uaeo9MvzKoyXuN6ZsbhtkL
Foundation for platform-native parity. The dashboard offered every control to
every display — a browser tab cannot reboot its host, a Tizen TV has no
device-owner concept, a BrightSign has no per-window brightness — so those
buttons did nothing, silently, and read as bugs. "UI that reports success and
changes nothing" is a recurring shape here; this ends it by letting the frontend
hide what a display cannot do.
The player DECLARES its capabilities at registration rather than the server
inferring them from a table, because only the player knows at runtime: an Android
device gains real screenshots when accessibility is switched on and loses Tier-2
commands when it is not device owner.
The trap this had to avoid is the opposite failure. Several hundred displays are
in the field declaring nothing, and none will update before the next dashboard
deploy — treating absence as "supports nothing" would strip the UI for the entire
fleet at once. So an ABSENT declaration falls back to a per-platform baseline,
while an EMPTY one is honoured as a player genuinely saying it can do nothing.
Those two cases are trivial to conflate and the difference is a dark dashboard.
Baselines carry only what has always worked on that platform. Anything
conditional — screenshots needing accessibility, kiosk needing device owner,
native sync needing one L2 network — is omitted, so a legacy display shows those
controls only once it declares them. A control that appears late beats one that
lies now.
Capability names are stable strings because they are persisted per device and
sent over the wire; renaming one silently disables a control on every display
still reporting the old name. An unknown name from a NEWER player is dropped
rather than invalidating the whole declaration.
1094 pass.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uaeo9MvzKoyXuN6ZsbhtkL
