* fix(playback): seek Embedded MPV steps relative to mpv's own position
Arrow keys and the ±10 s buttons in the Embedded MPV player advanced only
about a second per press when pressed repeatedly or held. The shortcuts
already asked for 5 s steps, but `EmbeddedMpvCommandRunner.seekBy` turned
each step into an absolute `seek` computed from `session.positionSeconds`,
which is floored to whole seconds, polled every 500 ms (helper snapshots at
most every 250 ms) and not refreshed by the seek reply. Every press inside
that window therefore landed on the same target.
Steps now go through a new `EMBEDDED_MPV_SEEK_BY` IPC / `seekEmbeddedMpvBy`
bridge method that every backend forwards as mpv `seek <delta>
relative+exact`: `seekBy` exports in the macOS addon and the Windows/Linux
`wid` addon (Linux over its JSON IPC socket), and a `seek-by` stdin command
in the frame-copy helper. mpv resolves the delta against its own position
and merges queued relative seeks, so presses accumulate as in mpv itself.
The absolute form survives only as a fallback for a preload without the
method or an addon binary without `seekBy`; the timeline scrub still
commits an absolute target.
Validated with a real mpv 0.39 IPC probe: three relative seeks in a burst
advance +15 s, three absolute seeks from one stale base advance +5 s.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
* fix(playback): drop speculative position update from relative Embedded MPV seeks
Review follow-up for the relative seek path.
The macOS and Windows/Linux `seekBy` exports advanced `snapshot.positionSeconds`
by the delta after dispatching the mpv command. That is not idempotent the way
the absolute seek's optimistic write is: the observer (mpv event thread, or
the Linux IPC poll) can already have stored the post-seek `time-pos` under the
same mutex, so adding the delta on top counted the step twice, and while paused
nothing corrected it. On Linux it also advertised a position that a failed
socket delivery never reached. Relative steps now leave the snapshot alone;
only the observed `time-pos` updates the position.
The packaged Linux frame-copy smoke now drives `seekEmbeddedMpvBy` through the
built app: a burst of three +2 s steps issued without waiting for snapshots has
to land on 6 s, and a -60 s step has to clamp at 0. The generated Y4M fixture
grows from 2 s to 12 s (about 415 KB) so the burst and the playing section that
follows stay inside the clip. Replayed against a local mpv 0.39 with the same
fixture and media server: burst -> 6.0, -60 -> 0.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
* docs(agents): mirror the Embedded MPV relative-seek contract into AGENTS.md
Review follow-up: the Shared Player Controls section documents the frame-copy
commands and shortcuts, so the relative seekEmbeddedMpvBy invariant lives
there too, next to the CLAUDE.md note.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
* fix(playback): reject a Linux relative seek the mpv IPC socket did not accept
Review follow-up: the Linux branch of SeekBy discarded the socket transaction
result and returned normally, so a step that never reached mpv looked like a
seek still awaiting observation. It now throws like a failed mpv_command_async
on the in-process engines; the renderer swallows the rejection and resyncs
from the next snapshot, and the main process logs it.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---------
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Lars Emig