Video Stabilizer 2.9.3 — local browser port of DePan
Modified and assembled 2026-11-05. Distributed under GNU GPL version 2
or, at your option, any later version. See LICENSE.txt.

DePan / DePanEstimate
  Copyright (c) 2004-2016 A.G. Balakhnin (Fizick).
  8-16 bit and multithreaded maintenance by Ferenc Pinter.
  https://github.com/pinterf/mvtools
  Pinned source commit: b41dca46d97916c9e86c7be2b7fc434349df0fd4
  The native baseline is DePan 2.15 + DePanEstimate 2.12.
  Corresponding original source excerpts are in src/vendor/depan.
  src/depan_core.cpp adapts the translation estimator and method=0 inertial
  smoothing to sequential WebAssembly. It removes Avisynth/Windows plumbing,
  interlacing, rotation/zoom estimation, future frames, and file I/O.
  Differences: initialized prior trust; deterministic +.011 valid-zero marker;
  a sign-preserving negative safety limit. Version 2.2 adds independent region
  references, source-relative footprints and confidence/consensus fusion.
  Version 2.3 adds a central-ratio grid, per-cell FFT/search configuration and
  unified single-region processing. New multi-region grids use spatial consensus
  in place of the individual temporal confidence-drop veto.
  Version 2.4 adds percentage sampling, cross-shaped selection, bounded
  dynamic workspaces and resource estimates.
  These additions are browser-port features, not original DePan modes.
  No original DLL is bundled.

FFTW 3.3.10, single precision, statically linked
  Copyright (c) 2003, 2007-14 Matteo Frigo
  Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
  https://www.fftw.org/fftw-3.3.10.tar.gz
  SHA256 56c932549852cddcfafdab3820b0200c7742675be92179e59e6215b340e26467
  GNU GPL version 2 or later; original copyright is in FFTW-COPYRIGHT.txt.
  Complete unmodified upstream source archive is supplied in the matching
  Video-Stabilizer-2.9.3-source.zip under src/vendor/fftw.

Emscripten 6.0.13 generated runtime / toolchain
  https://github.com/emscripten-core/emscripten
  Emscripten is distributed under MIT / University of Illinois/NCSA terms.
  The notices supplied by that release are in EMSCRIPTEN-LICENSE.txt.

The matching source ZIP contains all project source, original algorithm
excerpts, FFTW source, build scripts/instructions, deterministic test inputs
and validation records. See README-build.txt for an offline FFTW build.
No remote executable code, telemetry, Native Messaging host, native installer,
extra decoder, or desktop shortcut is used by the extension.


2.5.1: content-script invalidation cleanup, inline player SVG and byte-based
WebAssembly loading. Existing native calculations and saved defaults retained.

2.5.1: shared source-relative R/S/C controls and a separate five-second SVG
preview; legacy profiles retained until explicit adoption. Native core unchanged.

2.5.1: native parameter sliders and a shared UI/overlay color palette;
region status uses separate fills/dots. Settings and native core unchanged.

2.5.2: source-relative compensation edge-band preview; search and native
  stabilization remain unchanged.

2.6.0: independent icon preferences and expanded inputs; API 6 uses an implicit
  solve for stiff nonlinear limits while preserving normal native references.

2.7.0: strength presets, original comparison, local undo and explicitly saved
  personal defaults with recovery. Original custom storage is retained; native
  core and numerical defaults are unchanged from 2.6.0.

2.7.1: one common cutoff control with text strength guides; coupled preset
  buttons removed, existing stored profiles and native core retained.

2.7.2: logarithmic cutoff slider with reciprocal-period display; C in common
  controls and R/Q/zoom in Advanced. Native processing and stored Hz retained.

2.9.1: region-relative search with independent axis limits and arrow guides;
  old processing profiles retired, period display in seconds. Native core unchanged.

2.9.2: renamed to Video Stabilizer. Processing, saved-profile identifiers,
  icon artwork and optional one-time support are unchanged.

2.9.3: unchanged local WASM bytes are delivered as a packaged content-script
  data file. Browser startup, retry and seek do not fetch an extension URL.
  The raw WASM remains included for source verification and Node tests.