Every seek on Linux stalled the UI thread: the playback-restart handler read `time-pos` with a synchronous mpv_get_property from the GLib main context, which parks that thread on mpv's playloop for as long as the core takes — and the core's render path can itself be waiting on the main thread to post the next render job.
The position is now requested through the existing asynchronous property registry when the restart is dequeued, with the source identity captured at that moment, and the unchanged playback-restart envelope is sent when the reply lands. A source boundary — start-file or end-file — delivers any restart still waiting as a position-less envelope for its captured source and retires the reply, so no restart is ever reported after its source's boundary or attributed to the next source. No new event type or thread.
Live-TV clock generations were matched to mpv sources first-in-first-out: every
start-file popped the oldest registered open, on the assumption of exactly one
start-file per open in dispatch order. Opens without a generation on the same
player, an Android loadfile rejected silently by nativeCommand, and the
independent delivery of the command ack and the start-file event all broke
that, so a seek that reopened the stream could calibrate against the wrong
source.
The loadfile reply now carries mpv's playlist_entry_id on Android, Apple, Linux
and Windows, PlayerNative.open resolves with it, and the live session binds
each generation to that id explicitly. Source events that land before the
reply are buffered per id and replayed on binding; a rejected or unreachable
load fails its generation instead of leaving a phantom; opens with no
generation are invisible to clock binding. Android now reports a rejected mpv
command as COMMAND_FAILED like the other cores.
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.
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.
edde746