Kodekide

Kodekide are algorithms and hardware that encode and decode digital audio and video, enabling efficient storage and transmission. A codec combines an encoder and a decoder and is typically used with a separate container format such as MP4 or MKV that carries the encoded data.

Common audio codecs include lossy formats such as MP3 and AAC, and lossless formats such as FLAC and ALAC. Common video codecs include lossy formats such as H.264/AVC, H.265/HEVC, VP9 and AV1, as well as lossless options used in archival contexts.

How they work: codecs use techniques such as transform coding, quantization, and entropy coding to remove redundancies and irrelevancies in the signal. Lossy codecs discard some information to reduce data size, which may affect quality; lossless codecs preserve all information. The decoder reconstructs the signal from the encoded data, aiming for faithful playback.

History and usage: MPEG standards emerged in the 1990s, with MP3 audio becoming widely adopted in the same era. Today, streaming and broadcast commonly rely on HEVC, VP9, and AV1. Many codecs are patented and require licensing, while some open or royalty-free options exist, notably AV1 for video and Opus or FLAC for audio.

Note on containers: Container formats such as MP4 or MKV hold encoded streams and metadata but are not the same as codecs themselves.

Future developments include newer codecs such as AV2 and VVC (H.266) that aim for higher compression, as well as ongoing exploration of AI-assisted encoding techniques to improve efficiency and quality.