Files
hyperframes/packages/core/src/runtime
Vance IngallsandClaude Opus 5 2cd8b43087 fix(core,engine): make a group's preview match what the render bakes
Findings 8-11 and 16 — the render/preview parity set. All group audio,
all invisible to preview or to export alone, which is why each had a
passing test beside it.

9 — The preview bus wired only the automation lane, and
readElementAutomation reads data-automation, so a group's own
`data-volume` never reached the graph at all: the bus stayed at unity
while the render applied it. The export was ~8 dB quieter than what had
been auditioned. The test named for this asserted only
`resolves.not.toBeNull()`.

10 — The volume lane was scheduled on the FX chain's SOURCE, ahead of
the effects, breaking the contract scheduleVolumeLane's own docstring
states: "the volume lane rides the fader, after the effects — where a
DAW puts it, and the order the render bakes it in". The element path
honoured it; the group path did not, so any nonlinear group effect
previewed differently than it rendered. Both now land on a dedicated
post-FX fader node: input → chain → fader → mute → output.

11 — The bus deliberately outlives stopAll(), and groupInput early
-returned on an existing entry, so after a replay or a seek no new ramps
were booked and the gain held the previous pass's last value — 0 after a
fade-out, i.e. silent for the rest of the session. It re-anchors once
per play generation now (ElementFxHandle gains `reanchor`), and the
record keeps its `fx` handle so setRate can re-aim a group's automation,
which its docblock already claimed it did.

8 — The sub-mix summed members at unity (normalize=0) into a pcm_s16le
intermediate, so an over-unity sum hard-clipped at ±1 BEFORE the group's
FX and fader ran: pulling the fader down, or the Giant preset's
compressor, then operated on distortion. The intermediate is float now.
Both downstream readers already took float; applyVolumeEnvelopeToWav did
not, and does now, so a group's envelope is still baked sample-accurately
rather than silently degrading to the expression path.

The new level test is the one that matters here: EVERY tone in that file
is built on ffmpeg's `sine` source, which peaks at ~0.125 full scale, so
nothing in the suite could reach a clip whatever gain it asked for.
`writePeakTone` states the amplitude outright, and the test fails against
the 16-bit intermediate.

16 — mixGroupMembers forked mixAudioTracks' filter build and dropped its
automation-degradation retry, so a member envelope past this ffmpeg
build's expression limits failed the whole composition's audio where an
ungrouped one degrades to base volume with a warning. The retry is back,
reported on a successful result the same way. The group track is also
pushed with its volumeKeyframes when the envelope could not be baked,
instead of losing the group's automation silently.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-20 16:39:37 -07:00
..

Hyperframe Runtime Engine

This folder owns the runtime that powers preview and producer parity.

Current Direction

  • Runtime source of truth is converging on hyperframe.ts.
  • Build produces:
    • dist/hyperframe.runtime.iife.js (browser bootstrap)
    • dist/hyperframe.runtime.mjs (tooling/tests)
    • dist/hyperframe.manifest.json (version + sha256 + artifact map)
  • FE owns iframe runtime injection.
  • BE persists raw generated HTML without injecting runtime scripts.
  • Producer validates pinned runtime checksum from manifest before render.

Runtime Contract (Stable Surface)

Globals:

  • window.__player
  • window.__playerReady
  • window.__renderReady
  • window.__timelines
  • window.__clipManifest

postMessage:

  • parent -> runtime control:
    • source: "hf-parent"
    • type: "control"
    • actions: play, pause, seek, set-muted, set-playback-rate, enable-pick-mode, disable-pick-mode
  • runtime -> parent events:
    • source: "hf-preview"
    • type: "state" and type: "timeline"
    • type: "ready" — emitted once when installRuntimeControlBridge registers the control-message listener. The parent uses it to replay current playback state (set-muted, set-volume, set-playback-rate) so any control message sent before the listener was installed isn't lost. Emitted again on every iframe reload because the new runtime instance starts with no state.

Determinism baseline:

  • renderSeek is the producer-canonical seek path.
  • 30fps quantization and readiness gates are correctness requirements.

Build

bun run --filter @hyperframes/core build:hyperframes-runtime

Security Expectations

  • Runtime bootstrap URL must be version-pinned and host-allowlisted.
  • Iframe bridge payloads must be schema-validated.
  • Unsafe URL schemes (javascript: and unapproved data:) are rejected.
  • Fail closed if runtime bootstrap/handshake is not healthy.

Product Editing Model

  • Primary mode: prompt + element picking.
  • Secondary mode: manual precision controls.
  • Avoid timeline-first manual workflows as default product path.