Audiocodecs

An audio codec, or coder-decoder, is a software or hardware component that compresses and decompresses digital audio data. Codecs implement either lossless compression, which preserves the exact waveform, or lossy compression, which reduces data size by discarding information. The term refers to both the algorithm used to encode or decode audio and to the implementations that perform these tasks, while container formats carry the encoded data and related metadata.

Common lossless codecs include FLAC, ALAC, and WavPack, as well as PCM-based formats such as WAV and AIFF that store uncompressed audio. Lossy codecs include MP3, AAC, Vorbis, and Opus. Opus is notable for real-time communication due to low latency, while AAC and MP3 remain widely supported in consumer media and streaming ecosystems. The choice of codec affects compatibility, efficiency, and perceived sound quality at a given bitrate.

Codec selection is driven by bitrate, quality targets, latency, and licensing. Higher bitrates generally improve fidelity at the cost of larger file sizes; sample rate and channel count influence frequency response and spatial characteristics. Licensing varies: MP3 and some AAC implementations have historically required royalties in certain contexts, whereas Opus and many open formats like FLAC are royalty-free or openly licensed. Lossless codecs suit archival storage; lossy codecs are common for streaming and portable playback, where bandwidth or space is limited. Decoding is typically supported by hardware and software across devices.

In practice, audio codecs are implemented as encoders and decoders within media players, broadcasting equipment, and streaming pipelines. Platforms may transcode content between codecs to balance compatibility and bandwidth, and hardware decoders are integrated into smartphones, computers, cars, and home entertainment systems.