renderer_generated_frame_for_queue pushed a raw void* QVariant into the
display queue, but on_paint only unwraps OakSharedBufferPtr; the unwrap
failed and the widget painted blank. Paused display worked because
set_display_image wraps with oak_make_shared_frame. Wrap the queued
frames the same way. Also adds env-gated OAK_DEBUG_PLAYBACK
diagnostics.
- capi: oakengine_node_output_connection_at/_at_ex returned the source
node as the connection destination; the actual destination is
conn.second.node(). Out-edge enumeration was useless, so the node
view could only draw in-edges and randomly lost whichever edges
needed the out-edge path (random per context build order).
Regression test in oakengine_node_test
- project teardown: Project::clear() pre-notifies node removal while
nodes are fully constructed (observers used to crash on
half-destroyed nodes); childEvent suppresses the removal dance while
clearing; Node::disconnect_all/disconnect_edge get a silent mode for
teardown so no invalidation/events touch dying members
(is_being_cleared); ClipBlock marker disconnect guarded against
dead viewer/markers; ProjectCopier and PreviewAutoCacher drop
project references on Project::destroyed instead of disconnecting
dead objects at shutdown
- preview: add oakengine_preview_request_get_audio_sample_count; the
viewer queried sample count by passing nullptr to get_audio_samples
which rejects it, so all playback audio was silently dropped
- app: fix unterminated input-id memcpy in ResolveGroupInput
(nodeparamviewitem, widgetbridge) that corrupted every parameter id
- app: unsubscribe raw C-API event subscriptions in destructors of
NodeParamViewKeyframeControl, NodeParamViewConnectedLabel and
ExportDialog; playhead events used to fire into dead widgets
(crash when dragging the playhead)
- tests: preview request roundtrip (video frame + audio range) and
free-while-active teardown coverage; env-gated OAK_DEBUG_EDGES /
OAK_DEBUG_INVALID_INPUT diagnostics
- docs: investigation notes in docs/zh/
- nodeparamview: add visited set to get_distance_between_nodes, fixing
unbounded recursion (stack overflow) when the node graph has a cycle
- viewerdisplay: give texture_ a consistent owner via assign_texture();
borrowed queue textures are now retained, created ones freed, fixing
a dangling pointer that corrupted the heap and crashed in the GL driver
- playbackcache: resignal_requests() iterates a copy, handlers may
clear_request_range() while iterating (ASan container-overflow)
- preview C API: preview request ticket lambdas captured the request
state raw; after oakengine_preview_request_free the ticket outlived
the request and the finished callback wrote into freed memory
(heap-use-after-free). The finished flag is now a shared_ptr captured
weakly by the callbacks
- playback: oak_playback_frame regains a timestamp (num/den) filled
from olive::Frame; the viewer queue append no longer uses Rational()
for every frame, which made append_timewise drop all but the first
frame and froze the picture during playback
- mainwindow: open_node_in_viewer refuses sequence nodes; sequences
already have the Sequence Viewer, and saved layouts could otherwise
resurrect a redundant floating Viewer bound to the sequence
- app/ no longer includes engine C++ headers nor holds engine C++ types:
engine access goes through the oakengine C ABI plus C++ wrappers
(oakutil/oaknode.h, oakutil/oakvideo.h) and app-local mirror types
(tooltypes, trackreferencehandle, timelinecommonapp, keyframetypes,
subtitleapp, serializedlayoutinfoapp, nodevaluehandle, sliderdisplaytypeapp)
- engine: new C ABI functions for block/track/clip/transition navigation
and predicates, links, caches, waveform/playback, disk folder,
sequence_track_list, node_free, footage_is_valid, block_get_track,
get_brush; loadotio/saveotio ported to the current engine API
- OTIO is now a required dependency: CI and CD build it on every
platform, FindOpenTimelineIO fixed for OTIO 0.16/0.19 (the old deps
include requirement silently disabled OTIO everywhere), runtime
libraries are bundled into packages and copied next to macOS binaries
(oak_copy_otio_runtime)
- fix ProjectViewModel drag&drop mime read/write size mismatch (segfault)
- unify color label naming (k_olive -> "Oak") in the app-side mirror
- docs: OTIO required, FFmpeg minimum corrected to 6.0 (en/zh)
- gtest suite: 1925 passed, 0 failed
Move the pure-header utilities shared by app/ and engine/ out of
engine/common/ into a new shared/include/oakutil/ layer (define, lerp,
decibel, digit, range, crashpadutils, autoscroll, qtutils, filefunctions
declarations, and a trimmed xmlutils exposing a CancelAtom-free void*
overload). engine/common/ keeps forwarding headers so internal include
paths are unchanged; app/ now includes oakutil/* directly.
engine/node/project.h gains an explicit NodeGroup forward declaration
previously obtained transitively through the old xmlutils.h.
R7-A (Qwen 3.8 Max): oakengine/display.h rewritten to the POD contract
from r7-pure-abi-plan.md - oak_video_params everywhere, opaque
texture/frame handles with retain/free protocol (engine-heap control
blocks), OakSharedBuffer refcounted wrapper for the QVariant playback
path. All TexturePtr/FramePtr gone from app (47 sites).
R7-B (Qwen 3.8 Max): liboakengine.so exports 3486 -> 19 C++ symbols
(version script oakengine.ver: oakengine_* plus the documented
oakgl/oakvulkan dlopen plugin ABI). oakengine-obj OBJECT library feeds
both the shared lib and the test binaries (-rdynamic so dlopen'd
backends resolve engine objects).
Fix (Kimi K3): producer/consumer type mismatch - viewerdisplay
unpacks OakSharedBufferPtr but viewer.cpp pushed raw void* handles,
so no frame ever reached the display widget (all 5 vulkan viewer
tests timed out with 'never received a texture'). Producers now wrap
with oak_make_shared_frame / oak_make_shared_texture(retain).
Verified: build 0 errors, ctest 45/45, nm U _ZN5olive = 0 in
oak-editor/oak-render-worker/oak-cli, 19 exported C++ symbols in
liboakengine.so (all documented plugin ABI).
Every app module now reaches liboakengine exclusively through
oakengine_* C calls, EngineEventBridge subscriptions and app-side
handle headers (cliphandle/keyframehandle/nodevaluehandle/oakvaluehelper).
Direct C++ command construction, engine signal connect()s, and engine
type usage in MOC-visible signatures are gone: 557 -> 0 undefined
olive:: symbols in oak-editor.
- new primitives: clip_toggle_enabled (per-block flip), clip_set_linked,
sequence_add_default_transition (config-driven, sequence timebase),
node_set_label_many, node_set_color_label, plus observation getters
- toggle-links, default transitions, enable toggles, color labels, and
block renaming now go through the facade; the stray empty undo entry
from block renaming is gone along the way
- nest/multicam/waveform-sync stay as documented composites: they mix
redo_now intermediate state, graph surgery, and app-side computation
that a single primitive cannot express faithfully
- the timeline panel's command execution paths are now fully migrated
- new primitives: keyframes_set_time_many (conflict-safe batch time
move), keyframes_set_value_many (captured or explicit old values),
keyframes_set_bezier_many (double precision), and
keyframe_set_bezier_point (single handle with NaN-capture fallback)
- dialog and curveview drag finalization go through the facade; the
tests exercise the same global undo stack via oakengine_project_undo
- keyframeview/keyframeviewundo.{h,cpp} removed with zero remaining
references
- new facade API: set_input_at_time (element addressing, track=-1 for
all components at once), set_input_string_at_time, frame_time_base,
array_insert_at/remove_at, disconnect_ex (element-aware), and
keyframes_set_type_many (first cross-track keyframe op, addressed by
(time,track) pairs)
- the widget bridge's commit funnel, color path, array ops, label
disconnect, and keyframe set-type actions in keyframeview/curvewidget
now go through the facade; keyframeviewundo.h loses two consumers
- deliberate leftovers with rationale: keyframecontrol's multi-track
composite ops (documented track-0-only limitation of the keyframe
family), keyframeproperties dialog (needs a set_time primitive),
curveview's drag UX, and NodeInputDragger (already engine-side)
- new primitives: ripple_delete_in_to_out (ripple or gap fill plus
work-area state, one undo command), trim_clips_to (batch edge trim
returning a count), delete_empty_tracks (type-filtered batch), and
marker_remove_many (sparse marker deletion by timestamp array)
- delete-in-to-out, edit-to, delete-all-empty-tracks, and sequence
viewer marker deletion now go through the facade; empty operations
no longer push empty undo entries
- footage viewer marker deletion keeps its app path deliberately
(facade marker handles are Sequences, not generic viewers); the
tentative subtitle track and pointer drag chain stay as documented
leftovers
- new batch primitives: split_clips (link-preserving, single undo
command), delete_clips (gap replace + optional ripple with explicit
region support), ripple_delete_range, marker_add_ex with color
- razor/split-at-playhead, clip delete, ripple-to-point, track delete,
and the non-dialog marker path now issue facade commands instead of
the app's own undo command classes
- batch operations deliberately produce one undo command per user
action (deleting twenty clips is one entry, not twenty); selection
and transition removal stay UI-side as documented leftovers
- new facade API: video stream overrides (colorspace/range/interlacing/
premultiply), pixel aspect, image-sequence params, stream enable,
source start time, and colorspace candidates - all undoable
- project explorer proxy actions now run through FacadeProxyTask and
the facade media-management functions (ProxyManager references in
projectexplorer.cpp drop from 5 call sites to a comment)
- footage properties dialog reads/writes through the facade; its two
app-side undo command classes are gone
- handle-model fix: the footage handle is a heap state object, not a
plain pointer cast - oakengine_footage_borrow() wraps app-held
Footage nodes correctly (nine UB reinterpret_casts caught by the
DialogFootageProperties tests)
- NodeFactory's menu creation moves to UI-side widget/menu/factorymenu
(the factory only exposes its node library read-only now)
- DiskManager's cache-settings dialog is created through a registered
std::function handler (registered by Core at startup)
- OlivePluginInstance creates progress UIs through a
PluginProgressReporter interface (Null fallback headless) and queries
the active viewer through a provider callback, both registered by Core
- factory.h, diskmanager and pluginSupport no longer reference any
widget//dialog//panel//window headers or classes
- slider DisplayType enums sink to node/sliderdisplaytype.h (canonical
engine home); FloatSlider/RationalSlider alias them for compatibility
- DropWithoutSequenceBehavior enum sinks to common/dropworkflowbehavior.h
- Config errors now go through a registered ErrorHandler hook instead of
QMessageBox with a MainWindow parent; the style default no longer
depends on the UI style manager
- MainWindowLayoutInfo moves to node/project/serializer/ and its panel
dependency is reduced to a plain std::map alias (PanelLayoutInfo),
breaking the engine -> PanelWidget -> KDDockWidgets chain
- ProjectImportErrorDialog moves from task/ to dialog/projectimport/
- remove confirmed-redundant UI includes and give project.h/import.h/
project.cpp the direct includes they were borrowing transitively
- project.h includes folder/sequence headers directly (it used both
types in its own API all along)
- media color primaries/transfer tags now flow from the FFmpeg probe
through VideoParams into Footage::get_colorspace_to_use(); precedence
is user override > media tags > project default
- export nclc tags derive from the output colorspace (PQ/HLG/BT.2020,
P3, sRGB, Rec.601, Rec.709) instead of hardcoded BT.709
- new OCIO Color Grading (Log) node (lift/gamma/gain) and White Balance
node (kelvin temperature + tint, HDR-safe)
- LUT whitelist extended to 9 OCIO-supported formats
- waveform scope gains an RGB parade mode (GPU and software paths)
- tests updated for the new colorspace precedence
- playback timer uses the audio output device as its master clock: the
PortAudio callback counts consumed frames (including underrun
zero-fill) so video cannot drift away from what is heard; wall clock
remains as fallback when no clocked output is running
- output clock compensates for device output latency; new Preferences >
Audio buffer size setting (0 = auto)
- SampleBuffer::speed() now uses linear interpolation instead of
nearest-neighbor sampling
- regression tests: audio-clock driven timer (fwd/rev/speed), wall
clock fallback, interpolation correctness
Version is no longer hardcoded: at configure time CMake uses the tag
name when HEAD is exactly on a tag (leading "v" stripped), otherwise
the first 8 hex digits of the commit hash. When git is unavailable
(e.g. source tarball) it falls back to the contents of version.txt,
which is now the single place to bump the release version.
Also remove the temporary qDebug() flood in the audio playback path
(ViewerWidget::QueueNextAudioBuffer / ReceivedAudioBufferForPlayback,
AudioManager::PushToOutput).
- RenderManager: GPU-side members (context_, decoder_cache_,
shader_cache_, auto_cacher_, worker_pool_, decoder_clear_timer_) were
left uninitialized when the configured graphics backend is unknown
(e.g. dummy); ViewerWidget then dereferenced garbage and crashed.
Initialize them at declaration
- CurveView::SelectKeyframesOfInput ignored its reference parameter and
selected keyframes of every connected track; select only the
requested track's keyframes
- SeekableWidget::SeekToScenePoint dereferenced GetViewerNode()
unconditionally; skip the playhead update when no viewer is connected
- LoadOTIOTask: unknown root schema leaked the freshly allocated
project_ (delete + reset; OTIO is not enabled in local builds so this
file is compile-verified by inspection only)
Locked by new tests: RenderManagerDummyBackend,
TimeRuler.SeekToScenePointWithoutViewerIsNoOp,
CurveViewTest.SelectKeyframesOfInputSelectsOnlyRequestedTrack
- FrameRateComboBox: RepopulateList() left current index at -1 on first
fill, so GetFrameRate() returned 0/1 instead of the displayed first
entry until something called SetFrameRate()
- HandMovableView: default_drag_mode_ was never initialized; an early
Core::ToolChanged signal would setDragMode() with it (UB)
- File inputs marked with the 'lut_library' property (currently the
OCIO LUT node) now show a combo box populated from the global LUT
library above the path field: pick a library LUT directly, or use
'Other (Custom File)...' with the regular path field; selections go
through the standard undoable input-change path
- Refresh zh_CN translations with lupdate and translate all strings
introduced by the proxy dialog, LUT library, LUT picker, waveform
sync and footage start time work
- Document the new per-footage custom <proxy> attributes and the
'manual' source-start-time origin in the project file reference
- Add LutFileField UI tests
- Waveform sync no longer treats uncached waveform regions as silence:
the envelope extraction now reports a per-window validity mask and the
correlation skips invalid windows on either side, improving accuracy
for partially cached clips
- Add stretch/speed sync: AudioWaveformSync::EstimateStretchAndOffset
searches a playback-rate range plus offset, and a new timeline
context action 'Synchronize by Waveform (Adjust Speed)' applies the
estimated rate as a clip speed change (with undo) when plain offset
alignment is inconclusive
- Footage properties dialog gains a Source Start Time field so the
value used by source-time sync can be viewed and edited manually
instead of relying solely on auto-detected metadata; applied via an
undo command, with Footage::ClearSourceStartTime() for removal
- Regression tests for masked correlation, stretch estimation, the
envelope validity mask, and source-start-time set/clear
- Add a global LUT library: user-configurable directories (new
Preferences > LUT tab) scanned recursively for .cube/.3dl files; LUT
node file pickers offer the library dirs as sidebar shortcuts via a
'lut_library' input property handled by the param view bridge
- OCIOLutNode no longer fails silently: missing files, unsupported
extensions and OCIO load errors are recorded in last_error() and
surfaced in the status bar (input still passes through for rendering
safety)
- ColorDialog: re-enable the display -> reference conversion using
ColorProcessor::kInverse with a validity guard, and re-enable the
Display tab in ColorValuesWidget; covered by a round-trip regression
test proving the old OCIO inverse crash no longer occurs
- OCIOGradingTransformLinearNode: enforce the OCIO clampWhite >
clampBlack invariant per frame in Value() so keyframed/connected
values cannot produce invalid grading transforms, and constrain the
white clamp UI minimum whenever the black clamp is static
- Regression tests for LUT extension checks, direction switching, node
error reporting, LUT library scanning, display inverse round-trip and
clamp enforcement
- New ProxyDialog (Tools > Proxy Settings..., plus 'Proxy Settings...'
in the project panel and timeline Proxy submenus) unifying global
proxy settings, per-footage custom presets, generation and deletion
in one place instead of three scattered entry points; this also fixes
the Tools menu action opening the wrong preferences tab
- Preferences Disk tab gains an 'include audio in proxies' checkbox and
an ffmpeg executable path field (blank = auto-detect)
- Add ProxyDialog smoke tests
- Footage can store custom proxy parameters (width/height/crf/preset/
extension/audio) that override the global settings; they are
serialized with the project and used by every generation entry point
via Footage::GetEffectiveProxyParams()
- Proxies now include the source audio streams (AAC) unless disabled;
the proxy filename records the audio flag and offline audio rendering
decodes from the proxy when present
- ProxyTask resolves ffmpeg from the new FFmpegPath config key first,
then PATH, then common install locations (e.g. Homebrew on macOS),
instead of relying on PATH only; the error message points at the
preferences when no executable is found
- ProxyTask::BuildArguments() is extracted for testability
- Add ProxyIncludeAudio and FFmpegPath config defaults
- Add regression tests for the filename audio marker, config-backed
params, ffmpeg resolution, argument building, and custom-param
persistence
Replace every direct FFmpeg call in the editor and the render worker
with the pure C ffmpeg_bridge API, wrapped in thin C++ adapters that
preserve the original interfaces:
- avframeptr.h: olive::AVFrame adapter around FBFrame handles
- ffmpegutils: format conversion helpers on FB_* constants; the int
overload is renamed GetCompatibleBridgePixelFormat to avoid a silent
overload-resolution trap with the PixelFormat enum
- ffmpegdecoder/ffmpegencoder: rewritten as handle-based adapters over
FBDecoder/FBProbe/FBEncoder/FBScaler/FBResampler
- audioprocessor: FBAudioGraph push/pull adapter
- pluginrenderer/OliveClip: sws/pixdesc usage converted to FBScaler and
fb_pix_fmt_* queries
- AudioParams/channel layouts are plain uint64_t masks everywhere
Build integration: the root project no longer links FFMPEG directly;
only ffmpeg_bridge does. Binaries resolve the bridge library at runtime
via @loader_path inside the macOS app bundle (copied there post-build)
and via $ORIGIN/../ffmpeg_bridge/bin on Linux; on Windows the DLL is
installed next to the executables, so packages on all three platforms
ship the bridge library.
ffmpeg_bridge gains the extra API the adapters need:
fb_frame_make_writable, fb_decoder_get_format_duration,
fb_resampler_convert_frame, FB_PIX_FMT_YUV440P, SRT validation in
fb_probe_read_subtitle_stream, packed/planar fixes in
fb_encoder_write_audio, and a component-size fix in
fb_pix_fmt_component_size.
- Strip the dense RenderWorkerPool debug messages about cached/stale graph
snapshots and cleanup to reduce log spam.
- Add qDebug logging and status-bar feedback to
TimelineWidget::SynchronizeSelectedClipsByWaveform() so we can see why the
sync action does nothing (e.g. not enough cached clips or no usable offset).
- Add FixChannelLayout() helper to AudioProcessor::Open() to fall back to a
default native channel layout when the input/output layout is unspecified,
custom, or has a zero mask. This prevents FFmpeg's abuffer/aformat filters
from rejecting 'channel_layouts=0x0' on Linux.
- Log audio processor open parameters, viewer audio queue state, and
AudioManager::PushToOutput device/stream status to help diagnose silent
playback on Linux.
KDDockWidgets may need an event-loop iteration to finish opening or
tabifying a dock widget before raise() can switch to it. Defer raise(),
activateWindow(), and setFocus() via QMetaObject::invokeMethod with
Qt::QueuedConnection after show().
Call setAsCurrentTab() and activateWindow() on the ParamPanel dock widget
in ShowSelectedNodeInParamEditor so the parameter editor becomes the active
tab/window when invoked from the node view context menu or Shift+P shortcut.
In NodeParamView::SetSelectedNodes, after locating the target node item,
expand and raise its containing NodeParamViewContext dock widget so the
active tab/folded section switches to the one that actually holds the node.
- Ensure right-clicking a node that isn't currently selected makes it the
sole selection before showing the context menu, so 'Show in Parameter Editor'
operates on the clicked node.
- Emit all selected node/context pairs when jumping to the parameter editor.
- Guard dragging_items_ iteration in mouseReleaseEvent against deleted items
by snapshotting keys as QPointer and skipping null entries.
- Move Behavior-General options (hover focus, slider ladder, scroll zooms)
into the General preferences tab.
- Move Behavior-Audio option (audio scrubbing) into the Audio preferences tab.
- Promote remaining Behavior categories (Timeline, Playback, Project, Nodes,
Rendering) to top-level sidebar entries without the 'Behavior - ' prefix.
- Update Chinese translations for the new sidebar titles and fill unfinished
Behavior tab strings.
NodeView:
- Remove double-click jump-to-parameter-editor behavior; keep expand/collapse.
- Add right-click context menu item 'Show in Parameter Editor'.
- Add Shift+P shortcut bound to the same action.
Render:
- Fix crash in PreviewAutoCacher::ClearSingleFrameRenders when proxy playback
causes a render ticket to finish synchronously before the watcher pointer is
returned. Defer the watcher Finished signal via queued connection so the
caller can safely register the watcher before it is deleted.
Behavior preferences used a nested QTreeWidget with groups like General,
Audio, Timeline, etc. Replace it with one tab per group in the left sidebar
so users can jump directly to a category without expanding a secondary menu.
Also wire double-clicking a node in the node graph to emit a selection
signal with its context, causing the parameter panel to scroll to that
node's parameters (in addition to showing/raising the panel as before).
When no explicit color transform was set, ManagedDisplayWidget fell back to
the project's default input colorspace. For scene-referred reference spaces
like ACEScg / Linear this produced a raw, greenish image on the viewer
instead of a monitor-ready picture. Default to the OCIO config's default
display and view so the viewer looks correct out of the box, while still
honoring any Color Space / Display / View choice the user makes from the
context menu.
The Project Explorer previously only had an old Pre-Cache submenu that
required choosing a sequence. Replace it with the same Proxy menu that
the timeline uses:
- Generate Proxy: batch-generates proxies for all selected footage items
that have an enabled video stream, using ProxyManager and the current
proxy settings.
- Use Proxy: checkable toggle that enables/disables proxy playback for the
selected footage.
- Reveal Proxy / Delete Proxy: consistent with the timeline context menu.
Also make Footage::SaveCustom() write the <proxy> element whenever
proxy_enabled_ is true, even if proxy_path_ is empty, and load it back
in LoadCustom(). This preserves the user's Use Proxy preference across
project saves so it is restored on the next open.
Translation files updated with lupdate; zh_CN and zh_TW translations for
the new Project Explorer strings (and the matching timeline strings) are
filled in.
The Waveform, Vectorscope and Histogram panels were black when running on
the Vulkan / backend-neutral render path because ScopeBase::OnPaint()
returned early with a TODO. The viewer emits GPU textures that live in the
viewer's own renderer; on Vulkan each ManagedDisplayWidget has a separate
device, so those textures cannot be sampled directly.
Fix by:
- Adding a backend-neutral branch in ScopeBase::OnPaint() that downloads the
reference texture (cross-renderer if needed), color-manages it into a U8
offscreen texture, downloads it to a QImage, and draws via QPainter.
- Adding a pure virtual DrawScopeSoftware() to ScopeBase and implementing it
for WaveformScope, VectorscopeScope and HistogramScope.
- Fixing the managed_tex_up_to_date_ flag that was never set to true in the
OpenGL path, which caused the color-managed scope texture to be recreated
on every paint.
All gtest suites pass.
- The playback backup timer was using timebase_dbl() in seconds as its
QTimer interval, which truncated to 0 ms for normal frame rates. This
caused the timer to fire continuously and starve the event loop when
the video display was hidden, e.g. in Show Waveform Only mode, freezing
the UI and stopping the playhead. Multiply by 1000 to use milliseconds.
- If PlayInternal has neither video nor audio to prequeue, call
FinishPlayPreprocess immediately so the backup timer starts and the
playhead advances even in waveform-only mode with no audio.
- AudioWaveformView now uses the video frame rate as its timebase
(falling back to the default sequence frame rate), preventing the
enormous scene rect that froze the UI when it previously used the
audio sample rate.
- Call UpdateSceneRect() after changing the waveform timebase so the
QGraphicsScene bounds are recomputed immediately.
- Refresh the waveform view's viewer/timebase whenever the waveform
visibility mode changes, ensuring the correct timebase is applied
even if the node was connected earlier with a different setting.
- Use a divider of 1 (full resolution) for new sequences and for
footage-derived viewer parameters instead of the auto-downscaling
heuristic, so the viewer defaults to full-res preview.
- In AudioWaveformView, base the view timebase on the video frame rate
when video is present; fall back to the audio sample rate only for
audio-only sources. Using the audio sample rate as the view timebase
created an enormous scene rect (time * sample_rate * scale), which
froze the waveform view and stalled playback updates when showing
the audio waveform.
Mike-Solar