framestore-howl

VFPGA framestore-howl · runs in vfpga-runner

Model

The feedback flagship: a frame-store / howl-around circuit-bent VFPGA. A register tile holds the frame store; each frame the previous frame is read back, warped (zoomed, rotated, hue-spun, decayed) and re-mixed with the live input, then re-stored — the classic video howl-around / buffer-recirculation bend. Feedback gain past ~1 with decay near 1 gives runaway trails; the zoom drives a tunnel/spiral howl and the per-frame hue-shift a rainbow howl. CIN1 adds onto the zoom; GIN1 is a held gate that clears the store. The register ping-pong FBOs are render-local GPU state, swapped in place (no leak, no Y.Doc writes). vout1 is the composited howl; vout2 is the FRAME-STORE SEND — the warped recirculated frame (the feedback content before it remixes with the live input) — so you can scope, record, or externally process the howl loop.

I/O

Video in: 1 (vin1…vin1)
Video out: 2 (vout1 + vout2)

Controls (param knobs)

Slot	Knob	Range	Default	What it does
`p1`	feedback	0 … 1	0.6	Blend toward the recirculated frame (the feedback amount).
`p2`	zoom	0.9 … 1.1	1.02	Per-frame zoom about centre (>1 tunnel-in howl, <1 tunnel-out).
`p3`	hue	0 … 0.1	0.01	Per-frame hue rotation (rainbow howl).
`p4`	decay	0.8 … 1	0.96	Per-frame feedback decay (<1 trails fade, →1 runaway).

CV roles

Input	Role	What it modulates
`cv1`	ZOOM	Adds onto the per-frame zoom (patch an LFO to breathe the howl).

Each CV input has a bipolar SCALE attenuverter + OFFSET on the card, and an always-on scope.

Gate roles

Input	Role	What it triggers
`g1`	CLEAR	A HELD gate: while high, the frame store is wiped to black (clear the howl).

Gate inputs raw-pass into the host's synthetic gN_evt params; the factory hysteresis edge-detects rising edges (rise > 0.6 / fall < 0.4).

Usage

Add a vfpga-runner, pick framestore-howl from the card's load preset… menu, and patch the active outputs into OUTPUT / a video mixer / a downstream effect.