HCOM to WAV Converter

HCOM is a Huffman-coded audio format from the early Macintosh era, designed to shrink digitized sound for distribution on floppy disks and bulletin board systems when storage was precious and modems were slow. The encoder takes 8-bit unsigned PCM input, computes a frequency table of sample-delta values, and builds an optimal Huffman tree that replaces common deltas with short bit sequences. Compression ratios of 2:1 or better were typical for speech recordings, a meaningful saving when a 3.5-inch floppy held only 800 KB. Files were distributed as Macintosh resource forks and played through utilities like SoundApp and the BinHex ecosystem that defined Mac software exchange in the late 1980s. The format supported sample rates up to 22.255 kHz, matching the output capabilities of original Macintosh sound hardware. Tools such as SoX retain HCOM decoding support, ensuring that archived recordings remain accessible decades later. HCOM holds three practical advantages for preservation work: lossless compression that recovers the original samples exactly, a self-contained Huffman table embedded in each file for dependency-free decoding, and historical prevalence across thousands of vintage Mac sound archives.

WAV (Waveform Audio File Format) is an uncompressed audio container jointly developed by Microsoft and IBM, first published in August 1991 alongside Windows 3.1. Built on the Resource Interchange File Format (RIFF), WAV stores audio data — most commonly as linear pulse-code modulation (LPCM) — together with metadata describing sample rate, bit depth, and channel count. This straightforward structure has made WAV the de facto standard for uncompressed audio on Windows and a universally accepted interchange format across virtually every operating system, audio editor, and media player in existence. CD-quality WAV files use 16-bit samples at 44.1 kHz stereo, while professional workflows routinely employ 24-bit or 32-bit float samples at rates up to 192 kHz. A major advantage is zero-loss fidelity: because standard WAV applies no compression, the stored data is an exact digital representation of the original recording, making it the preferred choice for mastering and archiving. WAV also supports embedded metadata through INFO and BWF chunks, enabling timestamping and production notes. The main trade-off is file size — one minute of CD-quality stereo occupies roughly 10 MB — and the 32-bit RIFF structure imposes a 4 GB limit, though RF64 removes that ceiling.