Files
celery/sexp_effects/effects/blend_multi.sexp
giles bb458aa924 Replace batch DAG system with streaming architecture
- Remove legacy_tasks.py, hybrid_state.py, render.py
- Remove old task modules (analyze, execute, execute_sexp, orchestrate)
- Add streaming interpreter from test repo
- Add sexp_effects with primitives and video effects
- Add streaming Celery task with CID-based asset resolution
- Support both CID and friendly name references for assets
- Add .dockerignore to prevent local clones from conflicting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-02-02 19:10:11 +00:00

59 lines
2.8 KiB
Common Lisp

;; N-way weighted blend effect
;; Streaming-compatible: pass inputs as a list of frames
;; Usage: (blend_multi :inputs [(read a) (read b) (read c)] :weights [0.3 0.4 0.3])
;;
;; Parameters:
;; inputs - list of N frames to blend
;; weights - list of N floats, one per input (resolved per-frame)
;; mode - blend mode applied when folding each frame in:
;; "alpha" — pure weighted average (default)
;; "multiply" — darken by multiplication
;; "screen" — lighten (inverse multiply)
;; "overlay" — contrast-boosting midtone blend
;; "soft-light" — gentle dodge/burn
;; "hard-light" — strong dodge/burn
;; "color-dodge" — brightens towards white
;; "color-burn" — darkens towards black
;; "difference" — absolute pixel difference
;; "exclusion" — softer difference
;; "add" — additive (clamped)
;; "subtract" — subtractive (clamped)
;; "darken" — per-pixel minimum
;; "lighten" — per-pixel maximum
;; resize_mode - how to match frame dimensions (fit, crop, stretch)
;;
;; Uses a left-fold over inputs[1..N-1]. At each step the running
;; opacity is: w[i] / (w[0] + w[1] + ... + w[i])
;; which produces the correct normalised weighted result.
(require-primitives "image" "blending")
(define-effect blend_multi
:params (
(inputs :type list :default [])
(weights :type list :default [])
(mode :type string :default "alpha")
(resize_mode :type string :default "fit")
)
(let [n (len inputs)
;; Target dimensions from first frame
target-w (image:width (nth inputs 0))
target-h (image:height (nth inputs 0))
;; Fold over indices 1..n-1
;; Accumulator is (list blended-frame running-weight-sum)
seed (list (nth inputs 0) (nth weights 0))
result (reduce (range 1 n) seed
(lambda (pair i)
(let [acc (nth pair 0)
running (nth pair 1)
w (nth weights i)
new-running (+ running w)
opacity (/ w (max new-running 0.001))
f (image:resize (nth inputs i) target-w target-h "linear")
;; Apply blend mode then mix with opacity
blended (if (= mode "alpha")
(blending:blend-images acc f opacity)
(blending:blend-images acc (blending:blend-mode acc f mode) opacity))]
(list blended new-running))))]
(nth result 0)))