SimpleSSTV vs SSTV+

SimpleSSTV is a native iOS app for encoding, decoding, and live-transmitting slow-scan television (SSTV) signals — the method ham radio operators use to share images over audio frequencies. Slow-scan television converts images to audio tones. Each pixel's brightness becomes a specific frequency between 1500-2300 Hz. Sync pulses at 1200 Hz mark line boundaries. The result is an audio signal you can transmit over any voice-capable radio, or record for later playback. SSTV has been used by amateur radio operators since the 1950s. It's still actively used today on HF bands, VHF repeaters, and for receiving images from the International Space Station. ENCODING (Image → Audio) • Load any image from your photo library, camera, or Files • Automatic resize and crop to SSTV resolution • 21 supported modes covering all major SSTV formats • Real-time encoding with progress visualization • Play audio directly through speakers for VOX-triggered transmission • Export to WAV or M4A for later use • Optional FSK ID and CW ID (Morse code) callsign transmission • Test pattern generator for signal testing LIVE CAMERA MODE • Real-time camera feed with front/back camera switching • Three trigger modes: Continuous, Motion-triggered, or Periodic interval • Adjustable motion sensitivity with adaptive background model • Captures and encodes directly from camera to audio • Perfect for portable operation, field day, and unattended stations DECODING (Audio → Image) • Load WAV, M4A, or MP3 audio files containing SSTV signals • Live microphone capture for real-time SSTV reception • Automatic mode detection via VIS code identification • Progressive line-by-line image preview during decode • FSK callsign detection from received signals • Precision audio trimming with dual-view waveform editor • Re-decode saved images with different mode, sync offset, or slant correction • Handles real-world signal imperfections: timing drift, noise, sample rate variations • Optional decode watermark stamps mode, timestamp, and callsign on received images • Waterfall spectrogram display shows signal frequency over time SUPPORTED MODES (21 total) • Martin M1, M2, M3, M4 • Scottie S1, S2, S3, S4, DX, DX2 • Robot 36, Robot 72, Robot BW8 • PD50, PD90, PD120, PD160, PD180, PD240, PD290 • Wraase SC2-180 ISS SSTV EVENTS • Get notified when the International Space Station transmits SSTV images • Automatic alerts before and during events, with frequency, mode, and callsign info • Info card on the decode tab with event details and countdown FAQ & SETUP TIPS • Practical advice on audio setup and USB adapters • Decode quality troubleshooting • Quick reference for all 21 SSTV modes IMAGE LIBRARY • Automatic saving of encoded and decoded images • Grid view with full preview, metadata, and sharing • Re-decode any saved image with different settings • Filter by encoded or decoded 10 LANGUAGES Available in Arabic, Chinese (Simplified), Dutch, English, French, German, Polish, Portuguese (BR), Spanish, and Turkish — with full right-to-left support. PRIVACY No accounts, no analytics, no tracking. Your images and audio stay on your device. Free to encode and decode. Optional one-time Pro purchase unlocks watermark customization and Listening Station Mode. We do not use, sell or share your data for advertising or marketing purposes. Be aware: Encoded images are audio signals — anyone receiving the audio can decode them! REQUIREMENTS • iOS 17.6 or later • Camera access for live mode • Microphone access for live decode Built by a ham radio operator for ham radio operators. 73!

SSTV+ is a Slow Scan Television audio encoder and decoder designed for amateur radio enthusiasts. Use your iPhone’s microphone to listen for SSTV audio signals. SSTV+ automatically detects the VIS mode and progressively reconstructs the image entirely on your device. You can also select a photo from your library, encode it as standard SSTV audio, play it through the device speaker, or export it as a WAV file. Key Features: • Receive and decode SSTV audio signals in real time • Automatically detect VIS modes • Encode photos as SSTV audio • Scale, fill, crop, and reposition images • Support Robot 36 and Robot 72 • Support Martin M1 and Martin M2 • Support Scottie S1 and Scottie S2 • Support PD 90, PD 120, and PD 180 • Keep a local history of received and transmitted images • Optionally retain original received audio • Export and share WAV audio files • Save decoded images to your Photos library Completely Offline: SSTV+ requires no account or sign-in and does not connect to any servers. Signal detection, image decoding, and audio generation are performed entirely on your device. The app contains no advertising, user tracking, analytics SDKs, or cloud synchronization. Your photos, audio, and history remain stored locally on your device. Nothing is uploaded to the developer or shared with third parties. All core features remain available without an internet connection. Permissions: • Microphone: Used only to receive and decode nearby SSTV audio signals • Photos: Used only when you choose a photo for encoding or save a decoded image SSTV+ only processes and plays audio. It does not directly transmit radio-frequency signals. When using the app with external radio equipment, please follow the amateur radio regulations applicable in your country or region.