[piotrasd]

Hi
some time ago im discover 2 programs
"jpegoptim" https://github.com/tjko/jpegoptim
and
"optipng" http://optipng.sourceforge.net

With this program im execute 2 commands on xbmc - source

find -name "*.jpg" | xargs jpegoptim --strip-all
find -name "*.png" | xargs optipng -o7

This both command optimalize - compress graphic files without loosing quality but in some case decrease file size even on 80% !!!!!

examples
** Processing: ./usr/share/xbmc/addons/visualization.vortex/resources/Textures/checker.png
256x256 pixels, 8 bits/pixel, 256 colors in palette
Reducing image to 1 bit/pixel, 2 colors in palette
Input IDAT size = 1469 bytes
Input file size = 2387 bytes

Trying:
zc = 9 zm = 9 zs = 0 f = 0 IDAT size = 66
zc = 9 zm = 8 zs = 0 f = 0 IDAT size = 66
zc = 8 zm = 9 zs = 0 f = 0 IDAT size = 66
zc = 8 zm = 8 zs = 0 f = 0 IDAT size = 66

Selecting parameters:
zc = 8 zm = 8 zs = 0 f = 0 IDAT size = 66

Output IDAT size = 66 bytes (1403 bytes decrease)
Output file size = 222 bytes (2165 bytes = 90.70% decrease)

** Processing: ./usr/share/xbmc/addons/screensaver.xbmc.builtin.black/icon.png
256x256 pixels, 4x8 bits/pixel, RGB+alpha
Reducing image to 1 bit/pixel, 2 colors in palette
Input IDAT size = 603 bytes
Input file size = 718 bytes

Trying:
zc = 9 zm = 9 zs = 0 f = 0 IDAT size = 31
zc = 9 zm = 8 zs = 0 f = 0 IDAT size = 31
zc = 8 zm = 9 zs = 0 f = 0 IDAT size = 31
zc = 8 zm = 8 zs = 0 f = 0 IDAT size = 31
zc = 7 zm = 9 zs = 0 f = 0 IDAT size = 31

Selecting parameters:
zc = 9 zm = 9 zs = 3 f = 0 IDAT size = 31

Output IDAT size = 31 bytes (572 bytes decrease)
Output file size = 159 bytes (559 bytes = 77.86% decrease)


etc. !!! this should be privided before Gotham come to Final
This improvment for sure speed up - RPi and other ARMs builds

[davilla]

Please provide timing tests that show load/decode info. Then I might be convinced to look into this further.

Size does not matter much, disk reads are in blocks of 512/1024/2049/4906 bytes, not single bytes.