H264Kompression

H.264, also known as AVC (Advanced Video Coding), is a video compression standard developed jointly by ITU-T Video Coding Experts Group and ISO/IEC Moving Picture Experts Group. Finalized in 2003, it quickly became a dominant codec for high-definition video and remains widely used across media formats, streaming services, and broadcast systems.

The standard uses a combination of techniques to achieve high compression efficiency. Core methods include block-based motion compensation, intra-frame prediction, transform coding with a reversible integer transform, quantization, and entropy coding. H.264 supports multiple picture sizes and frame types, uses variable block sizes, and employs a deblocking filter to reduce compression artifacts. For entropy coding, H.264 supports two modes: CAVLC (Context-Adaptive VLC) and CABAC (Context-Adaptive Binary Arithmetic Coding), with CABAC typically available in higher-complexity profiles.

Profiles and levels organize feature sets and constraints. Common profiles are Baseline, Main, Extended, and High. The High profile offers the greatest efficiency and is widely used for Blu-ray, streaming, and HD delivery, while levels specify limits on parameters such as resolution, frame rate, and bitrate to ensure interoperability across devices.

Applications and impact. H.264 is deployed in Blu-ray Discs, online video streaming, video conferencing, and many broadcast workflows. It achieved broad adoption due to strong compression performance, mature hardware support, and broad compatibility across devices and software. While newer codecs exist, H.264 remains a foundational codec in many systems.

Licensing and considerations. H.264 is covered by patents held by multiple entities, and licensing may be required for commercial use. This has influenced deployment decisions and the availability of optimized encoders and decoders across platforms.