Robot36 - SSTV Decoder for Linux

Decodes Slow Scan Television (SSTV) images from audio input.

Original Android app by Ahmet Inan (xdsopl). Linux port by CrystalSky, 2026.

Features

• All SSTV modes: Robot 36/72, PD series (50-290), Martin 1/2, Scottie 1/2/DX, Wraase SC2-180, HF Fax, Raw
• Multiple audio backends: ALSA, PipeWire, JACK (native), javax.sound.sampled (fallback)
• Desktop audio monitor via PipeWire/PulseAudio loopback
• Auto mode detection, VIS code display
• Real-time scope, waterfall/spectrogram, peak meter
• Dark/light themes
• Auto-save decoded images

Installation

Arch Linux You can find the package in the AUR

paru -S robot36-linux

Other Distros Check the Releases. i'll add some install commands here later

Build

Requires: java (JDK 17+), gcc, make

Optional native backends (auto-detected):

• ALSA: libasound2-dev
• PipeWire: libpipewire-0.3-dev
• JACK: libjack-dev

./build.sh
./build/robot36

If native backends are unavailable, the app falls back to javax.sound.sampled.

Run

./build/robot36

Or directly:

java -jar ./build/robot36.jar

The native library librobot36_audio.so is loaded automatically from the jar's directory.

Desktop Audio Capture

To capture desktop audio (e.g., from a browser playing SSTV), create a loopback:

pactl load-module module-loopback latency_msec=1

Then select the loopback source from Audio > Audio System (choose your backend) > Input Device.

Audio Backends

Backend	Latency	Notes
ALSA	Low	Direct hardware access
PipeWire	Low	Integrates with PulseAudio/PipeWire
JACK	Lowest	Requires JACK audio server running
javax	Medium	Fallback, no special setup needed

Select from the Audio > Audio System menu.

License

Original code copyright Ahmet Inan <xdsopl@gmail.com>. Linux port copyright CrystalSky, 2026.

This software is provided 'as is' without warranty.