Kostya's Boring Codec World

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2021-06-23 03:30:06

I’ve finally finished polishing out decoders for all Duck codecs (before it was bought by Baidu) and now they all seem to work fine (except AVC, that one can wait for later—much much later). And while I moved to even more hairier and painful tasks (reorganising nihav-core and even documenting it) now, as I have full understanding how those codecs work, I can give an overview of their design (not the bit-by-bit description of the format, we have The Wiki for that but rather most notable features and similarities to other codecs) and form my opinion on them.

Somehow this might be their most original codec. While it’s simple codec with delta prediction I can’t remember any other codec that used a variable-length codebook with byte indices. Also this is the only codec in the family that works with RGB (16- and 24-bit modes even; the rest of codecs use YUV).

This one is a trivial codec for real-time video capturing (hence the name) that codes deltas with fixed quantisation scheme (2, 3 or 4 bits deltas with predefined step sizes).