Sony's XAVC codec is designed to reduce 4K video to manageable proportions. Announced at the same time as Sony's new F5 and F55 cameras, it forms part of an ecosystem that allows camera operators and post production specialists to choose the best workflow for the task in hand - from low-bitrate and highly compressed (but still distinctly 4K), all the way to raw, uncompressed.
Reactions to this new format have been mixed, with some expressing surprise that yet another H.264-based format is needed, while others have praised Sony for creating such a versatile environment for high-end creativity.
But in order to arrive at a valid opinion, it's essential to understand the facts. And here, at last, is Sony's own detailed explanation of this new codec. It's a rather technical read, but it does show very clearly where 4K, the F5 and F55, and XAVC sit in the video production landscape.