tree 63659c1496e2f1ab654a6df96e3606e4a7a51269
parent a84503456d4276348da3e80de7569adb1b389a60
author Vincent Rabaud <vrabaud@google.com> 1670578752 +0100
committer Vincent Rabaud <vrabaud@google.com> 1670792698 +0000

K-means: misc refactoring and speed-ups.

Previous suggestions are implemented:
- store centroids once and for all
- do not store all distance: only the current one and the minimum one
- store twice more indices in 2d AVX2

On rtc_screen, speed 0, 50 runs, speed-ups are in %:

File	encoding_spdup:
screen_recording_crd.1920_1080.y4m	0.289
screenshare_buganizer.1900_1306.y4m	0.136
screenshare_colorslides.1820_1320.y4m	0.232
screenshare_slidechanges.1850_1110.y4m	0.110
screenshare_youtube.1680_1178.y4m	0.534
slides_webplot.1920_1080.y4m	0.112
sc_web_browsing720p.y4m	0.548
screen_crd_colwinscroll.1920_1128.y4m	0.225
{OVERALL}	0.273

Speed 10:

File	encoding_spdup:
screen_recording_crd.1920_1080.y4m	0.277
screenshare_buganizer.1900_1306.y4m	0.382
screenshare_colorslides.1820_1320.y4m	0.391
screenshare_slidechanges.1850_1110.y4m	0.341
screenshare_youtube.1680_1178.y4m	0.813
slides_webplot.1920_1080.y4m	0.287
sc_web_browsing720p.y4m	0.611
screen_crd_colwinscroll.1920_1128.y4m	0.234
{OVERALL}	0.417

Change-Id: I7178ec5c89c9667aac1818c9eb1eda33ef8f81a9