Frame timelines: position as a destination, for the FS1R's scratch mode and the V-Synth's Time Trip #158

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opened 2026-10-06 16:24:13 +00:00 by bcox · 0 comments

bcox commented

2026-10-06 16:24:13 +00:00

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bcox asked on 2026-10-06 for a ticket for each gap docs/feature-survey.md names without one, whether or not it is ever done. Engine claims are from reading the tree at 6a3fede9 on main. Instrument claims are from that document's research, read from the manuals by research agents and not re-checked; the sources are listed there. Nothing here is built, measured or listened to.

Summary

A frame timeline runs at its speed lane and is not positioned from outside. The FS1R's FSEQ has a scratch mode in which a controller sets the position in the formant sequence, and the V-Synth's Time Trip pad stops the wave "at the current playback location" and moves it either way under a finger "without affecting the pitch". The FM pair's and the unvoiced layer's frame timelines are the engine's formant sequences.

What the tree has

FrameEnvelope in dsp/frame_envelope.h with up to kMaxFrames frames, a speed lane and a curve per segment; four timelines on the pair.

The work, as a sketch

A position lane, in frames or as a fraction of the sequence, that when routed overrides the clock: the timeline reads the frame pair the position falls between and crossfades them, as it does when running.

Open

Whether a position jump is a click on a lane that is not interpolated, and whether the pad's "beat keep" (chase back to where playback would have been) is wanted.

bcox asked on 2026-10-06 for a ticket for each gap `docs/feature-survey.md` names without one, whether or not it is ever done. Engine claims are from reading the tree at `6a3fede9` on `main`. Instrument claims are from that document's research, read from the manuals by research agents and not re-checked; the sources are listed there. **Nothing here is built, measured or listened to.** ## Summary A frame timeline runs at its speed lane and is not positioned from outside. The FS1R's FSEQ has a scratch mode in which a controller sets the position in the formant sequence, and the V-Synth's Time Trip pad stops the wave "at the current playback location" and moves it either way under a finger "without affecting the pitch". The FM pair's and the unvoiced layer's frame timelines are the engine's formant sequences. ## What the tree has - `FrameEnvelope` in `dsp/frame_envelope.h` with up to `kMaxFrames` frames, a speed lane and a curve per segment; four timelines on the pair. ## The work, as a sketch - A position lane, in frames or as a fraction of the sequence, that when routed overrides the clock: the timeline reads the frame pair the position falls between and crossfades them, as it does when running. ## Open Whether a position jump is a click on a lane that is not interpolated, and whether the pad's "beat keep" (chase back to where playback would have been) is wanted.