HCOM to OGA 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.

OGA is the audio-only file extension within the Ogg container framework maintained by the Xiph.Org Foundation. While .ogg traditionally served as a catch-all extension for any Ogg-encapsulated stream, the introduction of .oga in 2007 brought clarity by explicitly signaling that a file contains only audio data. Under the hood, OGA files can carry audio encoded with Vorbis, FLAC, Speex, or Opus — the container is codec-agnostic, serving as a transport wrapper with support for chained logical bitstreams and granule-based seeking. One benefit of OGA is interoperability: applications that encounter the .oga extension can optimize for audio-only playback without probing for video tracks, resulting in faster load times and lower memory usage. Because the Ogg container and its associated codecs are entirely open-source and royalty-free, OGA avoids the patent licensing complexities that affect proprietary formats. The format supports Vorbis comment metadata for tagging artist, album, and track information in a standardized way. OGA plays natively in Firefox, Chromium-based browsers, VLC, and most Linux desktop environments, making it a practical choice for web audio distribution and archival workflows.