screentinker/docs/player-parity.md

Player parity matrix

What each player can actually do, verified against the code rather than assumed. This is the document that says where the remaining work is, so a wrong "yes" here is worse than a missing row: it puts a control on the dashboard that cannot work.

Capability names come from server/lib/player-capabilities.js. Players declare their own set at registration; a player that declares nothing falls back to the per-platform baseline in that file.

Legend — ✅ supported · ⚠️ partial/conditional (reason given) · ❌ not supported (reason given)

BrightSign runs the same server/player/index.html as the browser, so it differs only where the autorun.brs host bridge adds something the browser cannot reach.

Playback

capability	Android	Web	Tizen	BrightSign
playback.video	✅ ExoPlayer	✅ <video>	✅ AVPlay	✅ hardware plane
playback.image	✅	✅	✅	✅
playback.widget	✅ WebView	✅ iframe	✅ iframe	✅ iframe
playback.youtube	✅ WebView embed	✅ IFrame API	✅ iframe embed	✅ IFrame API
playback.zones	✅	✅	✅	✅
playback.transitions	✅ GL wipes (#204)	⚠️ declared only when the bundle loads — a failed load hard-cuts rather than breaking playback	✅	⚠️ as web
playback.pip	✅ PipOverlay	✅ #pipContainer	✅	✅

Audio

capability	Android	Web	Tizen	BrightSign
audio.mute	✅ incl. YouTube via IFrame bridge	✅	✅ incl. YouTube via postMessage	✅ as web
audio.volume	✅ set_volume	✅ set_volume	❌ no set_volume handler exists — the dashboard slider does nothing today	✅ as web

Display

capability	Android	Web	Tizen	BrightSign
display.rotation	✅ native rootView.rotation	✅ CSS transform	✅ CSS + AVPlay for video	⚠️ host rotates the output via roVideoMode; CSS alone cannot turn the hardware video plane
display.power	✅ screen_off / lock_now	❌ a browser tab cannot power a panel — the overlay only paints black	❌ screen_off draws a black overlay, deliberately, "so the command still does something visible"	⚠️ media teardown always works; CEC is best-effort and absent on some units
display.resolution	❌ no video-mode control in the app	❌ not addressable from a browser	❌	✅ roVideoMode via the host

Remote view and control

capability	Android	Web	Tizen	BrightSign
remote.screenshot	⚠️ view capture always; full-screen only with accessibility or MediaProjection	⚠️ canvas only — same-origin content, and the alpha probe rejects frames where no pixels arrived	✅ captureAndSend	⚠️ host framebuffer capture requires primary storage; falls back to canvas, which cannot read the video plane
remote.stream	✅	✅ 1fps	✅	⚠️ as web
remote.input	✅	✅	✅	✅

Lifecycle

capability	Android	Web	Tizen	BrightSign
system.restart_player	✅	✅ location.reload()	✅	✅ host rebuilds the widget — a page reload does not reliably return
system.reboot	✅ device owner	❌ a browser tab cannot reboot its host	❌ no Tizen API exposed to the app	✅ RebootSystem() via the host
system.self_update	✅ APK OTA (UpdateChecker)	❌ the server deploys the player; there is nothing for it to update	❌ .wgt updates go through Tizen's own store/CLI	✅ autorun.zip package update

Device management

Android device-owner territory. Everything here is ❌ elsewhere for the same reason — no equivalent privilege model exists on those platforms — so the column is collapsed.

capability	Android	Web / Tizen / BrightSign
system.kiosk	✅ lock-task, now persisted across reboot	❌ no device-owner concept
system.brightness	✅ Tier 0/1	❌
system.screen_timeout	✅ Tier 1	❌
system.install_apk	✅ Tier 2	❌ not an APK platform
system.shell	✅ Tier 2, handled in WebSocketService	❌
system.time	✅ Tier 2	❌

Synchronisation and resilience

capability	Android	Web	Tizen	BrightSign
sync.clock	✅	✅	✅	✅
sync.native	❌ no native protocol	❌	❌	⚠️ SyncManager, BOS 8.2.10+; multicast so all members must share one L2 network
offline.cache	✅ content downloaded to disk, resumable (Range + If-Range), revision-keyed	✅ service worker, resumable chunked prefetch, revision-keyed	✅ media cached to wgt-private (js/media-cache.js), resumable, revision-keyed — declared at runtime, since a build with no writable private storage must not claim it	✅ inherits the web player's service worker

---

Real gaps worth closing

Ordered by how visible the failure is to an operator.

1. Tizen audio.volume — dead control. set_volume has no handler in tizen/js/app.js; the only volume path is the on-device KEYCODE_VOLUME_* keys. The dashboard slider silently does nothing. Either implement the handler or let the capability hide the control.
2. Tizen offline.cache is partial. Closed. tizen/js/media-cache.js caches the media itself to wgt-private — resumable, so a panel on a bad link accumulates an asset across attempts instead of restarting from zero, and revision-keyed, so a replaced asset is still a miss. The capability is declared at runtime rather than assumed: a build that cannot write to private storage keeps quiet about it.
3. BrightSign remote.screenshot needs primary storage. Reachable today only via the canvas fallback, which cannot read the video plane, so screenshots show everything except the video. Resolves itself when a card or SSD is fitted.
4. display.resolution is BrightSign-only. Fine, but the dashboard should not offer it elsewhere.

Correctly impossible — do not "fix" these

• system.reboot on web/Tizen. No API exists. A browser tab rebooting its host would be a browser vulnerability.
• display.power on web. The overlay is the honest maximum; the panel stays lit.
• All of device management off Android. No equivalent privilege model exists on Tizen or BrightSign, and a web player has no device to manage.
• system.self_update on web. The player is the deployment; there is nothing to update.
• sync.native off BrightSign. It is BrightSign's own protocol, and the clock-derived one is the cross-platform answer that already works everywhere.

⚠️ Corrections needed in player-capabilities.js

Found while verifying this table. The baselines only apply to displays that declare nothing, so these are wrong for the existing fleet until each player ships its declaration:

• tizen claims audio.volume — no handler exists (gap 1 above). Should be removed.
• tizen omits remote.screenshot and remote.stream — both are implemented (captureAndSend, startStreaming). Should be added.
• tizen declares offline.cache itself now — the server baseline still omits it, which is correct: a fielded panel that has not been updated genuinely cannot hold media, and the baseline describes what an un-updated one can do.