Decoding Morse Code Is Far Harder Than Generating It, Developer Finds

A developer building a Morse code tool discovered that decoding signals is fundamentally more complex than generating them, because real-world transmissions are timing-imperfect and sender-speed varies widely. Unlike generation, where every dot and dash follows a fixed unit length, decoding requires inferring timing boundaries from raw, noisy signal data. The solution involved classifying pulse durations relative to the shortest detected pulse in a message, rather than relying on hardcoded absolute values. The project split into two separate tools — one for audio signals and one for image-based Morse — since each requires a distinct input pipeline despite sharing the same core ratio logic. The developer noted that the decoder worked flawlessly on self-generated test files but struggled with real amateur radio recordings, highlighting the gap between clean synthetic data and messy real-world input.