The Origins of Audio and Video Compression: Some Pale Gleams from the Past

The paper explores the history that led to all audio and video compression. The roots of digital compression sprang from Dudley's speech VOCODER, and a secret WWII speech scrambler. The paper highlights these key inventions, details their hardware, describes how they functioned, and connects them to modern digital audio and digital video compression algorithms. — The first working speech synthesizer was Homer Dudley's VOCODER. In 1928, he used analysis of speech into components and a bandpass filter bank to achieve 10 times speech compression ratio. — In 1942, Bell Telephone Laboratories' SIGSALY was the first unbreakable speech scrambler. Dudley with Bell Laboratories invented 11 fundamental techniques that are the foundation of all digital compression today. The paper concludes with block diagrams of audio and video compression algorithms to show their close relationship to the VOCODER and SIGSALY.