Hi Jerome On Wed, Oct 16, 2024 at 06:27:09PM +0200, Jerome Martinez wrote: > Le 16/10/2024 à 15:54, Michael Niedermayer a écrit : > > 3rd implemantation :) > > you might ask why i implement this 4?! times > > Heres why: (tests done with 4 rawlsb bits, 16bit per sample input) > > I tested on my side also including the speed as the goal is to avoid the > speed cost of the LSB, with 6K content from scanner (analog input, last bits > are more or less random). > Speed Compr > 0,037x 0,471 No patch > 0,051x 0,491 bitfield > 0,046x 0,489 rangecoder > > the 25% gain in the speed is clearly visible (actually it 27% in my tests) > with the bitfield version of storing LSB, but it is a lot less visible with > the rangecoder version (the one from today): > There is a small 0.5% gain in size at the cost of 9% of speed, it is not > worth it IMO. > > I prefer by far your first version (really storing LSB as raw), it is fast > as expected (25% less time) and adding the range coder creates something not > really interesting (20% less time "only" for so little gain in size compared > to 25%)
did you try qtable 1 ? strangely it performed better for the file i used compression wise also i cleaned the code up a bit and reposted, some of the code was not exactly optimized here the old "bitfield" real 0m5.545s real 0m5.655s real 0m5.643s vs. just now posted: real 0m5.407s real 0m5.393s real 0m5.404s thx [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Those who are too smart to engage in politics are punished by being governed by those who are dumber. -- Plato
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