JPEG loading speedup possible?

AuburnSounds / gamut

Image encoding and decoding library for D. Detailed layout control. Experimental codec QOIX.

Boost Software License 1.0

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JPEG loading speedup possible? #39

Open p0nce opened 1 year ago

p0nce commented 1 year ago

Graillon diffuse takes 34ms to decode, isn't it a bit much for a 1332 x 1276?

JPGD_SUPPORT_FREQ_DOMAIN_UPSAMPLING adds 7ms by itself

p0nce commented 1 year ago

Using that 34ms time as baseline:

[ ] Try for Row and Col not to be templated
[ ] expanded convert seemingly can be optimized
[ ] Col!4.idct not great at all

p0nce commented 1 year ago

So, there was a small YUV to RGB speedup, we can perhaps remove the tables if generalized, which will win 4kb ram :| The DCT/iDCT not that easy to optimize