=== Test libjpeg-turbo performance in Android ===

To test libjpeg-turbo performance you can use skia_bench tool provided with skia.

The command line to test jpeg decoding is: 
{{{
skia_bench -repeat 10 -Ddecode-filename yourimage.jpg
}}}

The bench results are in Android log ($logcat -d) and look like this:

running bench [640 480] decode_''XXXX''_''yourimage.jpg''

8888: cmsecs = yyyy 

565: cmsecs = yyyy

==== skia_bench log ====

By default skia_bench results output go in Android log.

If you want to change this, and for example, piut them into a file you have to configure Android log systeme with logcat command.
The example below clean the log, redirect it to "/sdcard/skia_bench.log" and setup a filter in skia tag.

To have more detail about logcat: [[http://developer.android.com/guide/developing/debugging/debugging-log.html#startingLogcat| Android wiki page]]
{{{
logcat -c
logcat -f /sdcard/skia_bench.log skia:D *:S &
skia_bench -repeat 10 -Ddecode-filename /sdcard/yourimage.jpg
}}}

==== Results ====

Panda
Linaro Android 4.0.3 ICS

skia_bench vanilla : 

{{{
libjpeg
D/skia    ( 7865): running bench [640 480] decode_4444_LinaroBackground-1920x1080.jpg
D/skia    ( 7865):   8888: cmsecs = 2200.57
D/skia    ( 7865):    565: cmsecs = 2207.14
D/skia    ( 7865):
D/skia    ( 7865): running bench [640 480] decode_565_LinaroBackground-1920x1080.jpg
D/skia    ( 7865):   8888: cmsecs = 1880.90
D/skia    ( 7865):    565: cmsecs = 1889.09
D/skia    ( 7865):
D/skia    ( 7865): running bench [640 480] decode_8888_LinaroBackground-1920x1080.jpg
D/skia    ( 7865):   8888: cmsecs = 1936.54
D/skia    ( 7865):    565: cmsecs = 1925.06
}}}

skia-bench with libjpeg-turbo but without any 565 or 8888 optimizations.
{{{
libjpeg-turbo
D/skia    (  201): running bench [640 480] decode_4444_LinaroBackground-1920x1080.jpg
D/skia    (  201):   8888: cmsecs = 2274.25
D/skia    (  201):    565: cmsecs = 2288.28
D/skia    (  201): running bench [640 480] decode_565_LinaroBackground-1920x1080.jpg
D/skia    (  201):   8888: cmsecs = 2006.49
D/skia    (  201):    565: cmsecs = 2010.12
D/skia    (  201): running bench [640 480] decode_8888_LinaroBackground-1920x1080.jpg
D/skia    (  201):   8888: cmsecs = 2021.33
D/skia    (  201):    565: cmsecs = 2017.81
}}}
libjpeg-turbo -current prototype with 565 and 8888 optimizations
{{{

D/skia    ( 4587): running bench [640 480] decode_4444_LinaroBackground-1920x1080.jpg
D/skia    ( 4587):   8888: cmsecs = 1244.52
D/skia    ( 4587):    565: cmsecs = 1232.39
D/skia    ( 4587):
D/skia    ( 4587): running bench [640 480] decode_565_LinaroBackground-1920x1080.jpg
D/skia    ( 4587):   8888: cmsecs = 975.11
D/skia    ( 4587):    565: cmsecs = 960.59
D/skia    ( 4587):
D/skia    ( 4587): running bench [640 480] decode_8888_LinaroBackground-1920x1080.jpg
D/skia    ( 4587):   8888: cmsecs = 1121.99
D/skia    ( 4587):    565: cmsecs = 1147.37
}}}