Smittix f7fad076c2 fix: Expand Scottie sync deviation search window to fix under-correction ...

The slant correction was severely under-correcting because bwd=50 caused
the sync deviation measurements to saturate after only ~25 lines (for a
2-sample/line SDR clock drift). Lines 25-256 all reported deviation=-50,
pulling the linear regression slope toward zero.

Increase bwd and fwd to 800 samples each — sufficient to track cumulative
drift from up to ~±200 ppm SDR clock offset across the full 256-line image.

Also use a full-sync-length (432-sample) Goertzel window instead of 1/3
length, giving ~111 Hz frequency resolution to cleanly separate the 1200 Hz
sync tone from 1500 Hz pixel data. Search is stepped at 5 samples (~0.1 ms)
for efficiency, keeping the goertzel_batch batch size at ~320 windows/line.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2026-02-19 11:04:06 +00:00

..

__init__.py

Replace broken slowrx dependency with pure Python SSTV decoder

2026-02-06 19:47:02 +00:00

constants.py

fix: Correct SSTV VIS codes and replace Goertzel pixel decoder with Hilbert transform

2026-02-19 09:23:15 +00:00

dsp.py

Replace broken slowrx dependency with pure Python SSTV decoder

2026-02-06 19:47:02 +00:00

image_decoder.py

fix: Expand Scottie sync deviation search window to fix under-correction

2026-02-19 11:04:06 +00:00

modes.py

fix: Correct SSTV VIS codes and replace Goertzel pixel decoder with Hilbert transform

2026-02-19 09:23:15 +00:00

sstv_decoder.py

fix: Add missing SSTV mode specs for HF decoding (PD90/PD160/PD240/ScottieDX)

2026-02-18 21:29:34 +00:00

vis.py

fix: Improve HF SSTV VIS detection reliability and error correction

2026-02-18 21:52:56 +00:00