HCOM to TTA 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.

TTA (True Audio) is a real-time lossless audio compression codec developed by Aleksander Djourik, with its origins tracing back to the early 2000s. The format reconstructs the original PCM stream bit-for-bit upon decoding, guaranteeing that no sonic detail is lost during storage or transfer. TTA handles standard CD-quality audio as well as high-resolution content up to 32-bit integer samples, making it suitable for everyday listening and professional archiving alike. Processing speed is one of TTA's defining strengths — the codec achieves fast encoding and decoding without heavy CPU demands, keeping it lightweight even on older hardware. The file structure supports ID3v1, ID3v2, and APEv2 metadata tags, so track information and album art travel with the audio. Hardware support appeared in several portable players, giving TTA a practical edge over some competing lossless formats. The open-source reference implementation ships under the GNU GPL, encouraging community adoption and third-party integrations. While newer codecs like FLAC have captured a larger share of the lossless audio landscape, TTA continues to serve users who value its simplicity and transparent compression.