Video on Linux went through a Flutter texture: 8-bit sRGB, which cannot carry
HDR at all, and which forced a whole-window Flutter recomposite for every video
frame. This moves it onto a wl_subsurface stacked below the Flutter surface, with
mpv rendering into an EGL window surface on it through the libmpv render API. The
subsurface is desynchronized, so video and UI now present independently.
With the plane in place HDR follows: the surface is described to the compositor
through wp_color_manager_v1 as the source's own curve and gamut - PQ or HLG,
BT.2020 - carrying whatever HDR10 static metadata the stream actually declares.
The description and the buffer it describes land on the same commit, staged and
validated before mpv is switched, so a PQ frame is never presented labelled sRGB.
A five-second watchdog bounds the one wait a compositor could otherwise leave
hanging. A session that cannot host the plane - X11, or a compositor without
wl_subcompositor - fails initialize with VIDEO_PLANE_UNSUPPORTED naming the
reason: the texture path is gone, and refusing by name beats degrading to
something the user cannot see. An SDR output, a missing capability or an 8-bit
config keep the plane and simply leave it undescribed.
The output's colour state is trusted only when it has been earned. Every landed
property step records itself as it lands; a reset or sequence that cannot
finish downgrades its result to unknown and marks the applied-output cache
untrusted until a clean apply earns it back. A plane whose output state cannot
be named is quarantined - hidden, its description withdrawn - and the
quarantine is recorded state: an unrelated visibility change cannot put a
mislabelled plane back on screen, and only a commit that resolves to a nameable
outcome lifts it. A rect collapsing to zero detaches the buffer exactly as
hiding does, a refused setVideoRect drops the Dart-side sent-rect cache so the
next layout pass retries for free, and a refused tone-mapping pick tells the
user instead of dying in a log.
NVIDIA's Wayland EGL (through at least 610.xx) offers no 10-bit unorm window
configs, so the plane takes half-float as the tier between 10-bit unorm and
8-bit, declares the whole surface opaque so the compositor never reads the
alpha those configs carry, and states GL_RGBA16F rather than a 10-bit lie.
Whether the output is in HDR is read from luminance headroom above its own
reference white rather than from the preferred transfer function, which current
KWin no longer answers PQ for; the margin is half a stop, because KWin reports
an undimmed maximum over a software-dimmed SDR white. Validated on an RTX 4090
(driver 610.57.04) under KWin 6.7.4 with locked-exposure photographs.
Who tone-maps is a user choice. The default is the compositor: photographed on a
400-nit HDR output against a PQ chart it keeps 400 -> 1000 nits monotonic and
separated where the player leg flattens them, because the player path drives
mpv's legacy vo_gpu, whose own standalone output scores the same. The gap is the
renderer, not the wiring.
The decision itself - what the source carries, what the output supports, what to
tell mpv and what to tell the compositor - lives in hdr_metadata.h, free of
Wayland and GTK so its luminance validation can be tested without a display
server. Sending an incoherent luminance set is a protocol error that disconnects
the client, so the rules are worth a unit test.
The deb, rpm and pacman packages now declare wayland-client, wayland-egl and EGL:
the plane links them directly and bundle-libs.sh deliberately never bundles them,
since they are coupled to the running compositor and GPU driver.
lib/dev/harness_main.dart is a second entrypoint for measuring this on hardware -
it drives one clip with scripted mpv properties and reports the colour state mpv
actually settled on. Nothing imports it, so it is tree-shaken out of the app.
Verified on a Steam Deck against an external 400-nit HDR display: the compositor
reports PQ / BT.2020, the connector carries HDR_OUTPUT_METADATA, and against mpv
vo=gpu-next on the same frame the shipped build sits 4.90 counts away overall -
closer to the reference HDR player than to its own SDR fallback.
The check that keeps Audio Passthrough out of the in-player settings
sheet dragged the first Scrollable ten times and then asserted the
label was absent. That scrolling never moved: at the pumped 900x700
viewport the sheet fits its own content, so maxScrollExtent is 0 and
the offset stays there through every drag. The assertion passed
identically with no drags at all.
It caught a reintroduced toggle only because the whole list happens to
sit in the element tree at rest. Grow the sheet, shrink the viewport or
give it a lazy delegate and findsNothing starts passing because the
label is offscreen rather than gone, with nothing in the test to say
so.
Land on the audio block that used to hold the toggle first, then
assert the absence. scrollUntilVisible throws when that block is
missing entirely, so the guard fails loudly instead of quietly
weakening.
Tunneled playback on an AFTMM judders continuously through 23.976p direct play.
The #1802 reporter isolated it: turning off Tunneled Playback with every other
setting unchanged makes it smooth, and their log shows tunneling active for the
whole session with E-AC3 bitstreamed and the decoded-PCM guard never firing.
Audio Passthrough looked like the trigger only because it is the one user-facing
switch that decides it. Passthrough off, or Downmix to Stereo on, both force the
Dolby track to decode to PCM, which trips the #1458 guard and takes tunneling
down with it. Passthrough on with downmix off is the only combination that keeps
a bitstreamed track, so it is the only one that stays tunneled.
Withdraw tunneling on that model for content at or below 30fps. The cut-off
keeps 4K50/60 tunneled, which is the workload Amazon documents the feature for.
The mechanism stays unconfirmed: tunneling fires no VideoFrameMetadataListener
and stops media3 counting frames in the codec, so nothing app-side can measure
the cadence. Only the trigger is established, and the quirk is scoped to it.
That needs a frame rate the app did not have. Neither MatroskaExtractor nor
Mp4Extractor populates Format.frameRate, and a tunneled session renders no
frames back for the native detector, so the server's rate now rides on the open
call. It is sent only for direct play, matching _primeDisplayCriteria: a
transcode's metadata describes the source, not what the server is about to send.
Also move Audio Passthrough out of the in-player settings sheet. It configures
the audio output route rather than the current playback, and applying it
mid-stream bounces the audio renderer and re-decides tunneling. Settings > Video
Playback already owns it, next to Tunneled Playback, which is applied the same
way. That description now mentions stutter, not only black HDR video, so the
workaround is findable on hardware this quirk does not cover.
The mpv backend failing to start the same 4K file is a separate defect and is
not addressed here; its uploaded log is no longer retrievable.
Consolidates duplicated logic behind shared implementations — paginated
grid tabs, focus chrome, cached remote stores, sheet selection columns,
the server artifact store and a test fixture layer — and removes code
that had become unreachable. Net reduction of about 5,500 lines with no
behaviour change.
Where a fix had landed separately in code that moved into a shared
helper, the fix was re-applied inside the helper rather than left behind
in the copy that went away.
Introduces shared seams for paginated views, D-pad reorder, media control
routing, async singletons and the device method channel, then points the
open-coded copies at them.
Also removes unused models and duplicated provider/server plumbing, folds
the twice-implemented artifact store in the server, and factors the
repeated Flutter toolchain prologue in CI into a composite action.
Collapse duplicated setup across the suite into six shared helpers under
test/test_helpers/ and rewrite the 28 suites that were open-coding it:
http_fixtures.dart jsonResponse() for http.Response JSON stubs
library_tab_scaffold.dart pumps library tabs under their required ancestors
multi_server_fixtures.dart MultiServerProvider wiring for widget tests
playback_report_fakes.dart PlaybackReportCall + fake report sinks
profile_stack.dart production-shaped profile dependency graph
theme.dart testMonoTokens for fast-settling widget tests
Net -1245 lines with no change in coverage or assertions.
Complete and revise every shipped locale against the current English source, preserve locale-specific plurals, and map script-specific Chinese locales through device, Intl, duration, and Plex boundaries.
Co-authored-by: emgeje <mgj@mgj.hu>
Co-authored-by: junyou1998 <junyou1998@gmail.com>
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