Polyglot Radio: Acoustic SDR

Polyglot Radio harnesses your device’s built-in speaker and microphone to send and receive digital and analog waveforms through the air. Powered by a high-performance native C++20 DSP core and a modern Flutter interface, Polyglot Radio continuously scans, arbitrates, decodes, and transmits 11 acoustic and near-ultrasound communication protocols—no extra radio hardware required! KEY FEATURES Autonomous Parallel Sentry: No manual mode switching required. Polyglot Radio simultaneously monitors matched-filter and energy-bank correlations across all supported waveforms, auto-detecting incoming preambles, VIS codes, and sync words to promote the correct decoder instantly. Real-Time Spectrogram Waterfall: Visualize incoming audio signals with a fluid, 512-bin rolling FFT waterfall running at 30 FPS. Zero-Copy Shared Canvas: Watch analog image sweeps decode line-by-line in real time on a dedicated 640×496 RGBA canvas (SSTV, HF WEFAX, and Hellschreiber). Smart RMS Squelch & Pre-Buffer Slicing: Dynamic noise-floor tracking with hysteresis and a rolling 5-second buffer ensures fast preamble bursts are never clipped or lost. Burst Archival & Offline Demodulation: Unrecognized signals exceeding squelch are automatically preserved to local storage as "Unknown Bursts." Re-run demodulation anytime, or import your own .wav files for offline decoding. Near-Ultrasound Data Transfer: Transmit and receive data silently over 18.5–19.8 kHz using 16-FSK with linear chirp preambles and Reed-Solomon RS(15,9) forward error correction. Amateur Radio Compliance Built-In: Station ID verification strictly gates transmission of amateur packet modes (APRS / AX.25) until an authorized callsign is entered. SUPPORTED WAVEFORMS & PROTOCOLS SSTV (Slow Scan Television): Robot 36, Robot 72, Martin 1 & 2, Scottie 1 & 2, PD-120 with live VIS sync and image rendering. Near-Ultrasound Data Modem: Inaudible 19 kHz 16-FSK carrier with Reed-Solomon error correction. APRS / AX.25: 1200-baud Bell 202 AFSK packet framing. CW (Morse Code): Variable 5–45 WPM smooth envelope transmission and audio decoding. PSK31: 31.25-baud BPSK with Varicode text transmission. Olivia MFSK: Multi-tone FSK with Walsh-Hadamard transform. HF WEFAX: 120 LPM maritime weather facsimile decoding onto the shared visual canvas. FT8: 8-GFSK Costas array framing. EAS / SAME: Dual-tone emergency alert transmission and SAME header generator. Feld-Hell (Hellschreiber): 122.5-baud dot-matrix facsimile transmission and raster engine. Rattlegram (COFDM): Experimental orthogonal frequency-division multiplexing transmission.