📡 ROBOT36 SSTV STUDIO

What is Robot36 SSTV?

Slow Scan TV (SSTV) is how ham radio operators send pictures over the air using nothing but audio tones. Robot36 encodes a 320×240 image into a 36-second sound by frequency-modulating luminance (Y) and color (Cr/Cb) into the 1500–2300 Hz band.

1500 Hz = black, 2300 Hz = white. Cr & Cb chroma alternate across line pairs to save bandwidth.

Decode Pipeline

A. VIS / mode detect — read the digital header code (Robot36 = 0x08) to lock timing & color params.
B. Demodulate — a Goertzel filter bank turns each audio window back into an instantaneous frequency.
C. Sync & slant — lock onto each line's 1200 Hz pulse to align rows (slant correction).
D. YUV decode — luminance (Y) is decoded at full res every line; chrominance alternates R−Y (Cr) on even lines and B−Y (Cb) on odd lines.
E. Reconstruct — the missing chroma channel is interpolated from adjacent lines, YCrCb → RGB, and pixels are painted line-by-line onto the 320×240 canvas.