5. Compression formats for multichannel audio bitrate reduction

5.1 Lossless and lossy

Lossless compression algorithms provide objective transparency, i.e. the decompressed signal is bit-for-bit identical to the original. But the compression ratio is 2 on average, and can be as low as 1. These ratios are largely insufficient for broadcast or transmission applications. Only archiving (sound libraries) can be a valid use.

Lossy algorithms aim for subjective transparency (the compressed sequence is perceived as being of identical quality to the original), but can be sensitive to successive compression-decompression (cascading or tandem coding).