Quote:
Originally Posted by Dark Shikari
Almost all the time in something like Lagarith is going to be spend in the arithmetic coder, which is almost necessarily not-SIMDable.
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It's actually a reasonably fast range coder, and keeps separate state in both threads; most of the time seems to be spent in prediction, which is already SIMD'd to hell and back. (There is no straight-C fallback code, just SIMD for most operations.)
Quote:
Originally Posted by zerowalker
Dark Shikari, you wouldn´t know how to implement YCoCg support in Lagarith?
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It's not knowing how, it's someone willing to do it. Although it might not be too hard to rip the guts out of ConvertToYCgCo and insert it into another conversion routine, it would be incompatible with every other Lagarith install out there right now.
I did do some testing with ConvertToYCgCo, though, and it does seem to help a little bit if you don't mind subsampling, but if color fidelity is important to you, YCgCo24 (or YV24) gains you almost nothing size-wise over RGB. Maybe 3-5%.