3.1 KiB
Automation and expressive control (Phase 16)
Track Gain/Pan lanes in the Mixer apply to audio and scheduled instrument voices. They use absolute project ticks, linear interpolation, hold-first/last outside points and the constant project tempo snapshot. A clip trim/move does not move track or effect automation: lanes belong to the project timeline. Instrument volume is controlled by its track Gain lane; the current sine has no timbre parameter. Track gain ramps and boundary fades are described in AUDIO_QUALITY.md.
Select a LADSPA node in Modular Graph and use Edit/Selected plugin automation.
Enter port tick mode value: mode 0 interpolates linearly, 1 holds until the next
point, and -1 removes the point at that port/tick (value ignored). Port names,
ranges and current tick are displayed. There are at most 32 points per plugin;
setting an existing port/tick replaces it. Integer/toggle controls require step
mode. Invalid values, ticks, ports or duplicate persisted points reject the edit
or file. Edits are undoable and rebuild on the control thread while stopped.
Effect lanes use the project tempo, hold first/last outside their range and apply before run at each exact sample. Distinct ticks rounding to one sample resolve to the later tick. Linear curves avoid stepping continuous controls; intentional step curves may click. The initial implementation calls run(1) while any lane exists, with connected preallocated buffers. CPU cost can be significant; only the documented LADSPA set is qualified. No worker, allocator, loader or clock is called from the host audio path. Native ABI 2 callers continue to use sample-offset parameter events, applied before equal-offset MIDI events.
Live MIDI input maps CC7 to per-channel volume (0..1), CC10 to pan (64 center), and CC64 to sustain (>=64 down). Volume/pan ramp over 5 ms. These fixed mappings apply to live sine voices, not track faders or prerecorded clips; controller capture, configurable learn and plugin MIDI are not supported. CC120/123 and Panic release all live voices and sustain and suppress already-started scheduled notes. Note-on velocity zero decodes to note-off. Repeated live note-on on one channel/pitch retriggers one voice; note-off releases it or marks it pending while sustain is held. Sustain-up releases pending voices, never newer retriggers. Seek, stop, teardown and disconnect clear live voices; plan reset returns controller values to unity/center. Equal-offset live events execute in input order before the sample; arrange note ends precede starts, and scheduled mixer values are evaluated at that sample. Overlapping arranged notes are independent.
Format v6 preserves v5 data plus effect lanes. A v5 plugin migrates with no lane and the project tempo. Repeated render/save/reopen, odd block partition, exact endpoints, seek/plan replacement, sustain/retrigger and controller ramp tests:
make test test-control test-plugins test-gui-plugins test-plugins-real
Physical controller devices and listening remain unqualified; no tempo map, latency compensation, MIDI capture, pitch bend or plugin crash isolation is added.