[opensource-dev] Openjpeg/KDU the cold hard metrics

Sheet Spotter sheet.spotter at gmail.com
Mon Sep 27 19:45:30 PDT 2010


I found a simple fix to the OpenJPEG v2 library that corrects the previous
crashes that occurred with the test harness.

The fix is attached to https://jira.secondlife.com/browse/SNOW-361

I also updated Robin's spreadsheet to reflect the improved performance.
OpenJPEG v2 is now marginally quicker than the OpenJPEG v1.3.0 that ships
with Viewer 2.

Previously the OpenJPEG v2 library was crashing when it skipped over packets
for higher discard levels. The library was skipping over too few bytes.

Earlier test results for OpenJPEG v2 were performing a full decode. The
"Reduce" feature (that performs partial decodes when the image was
incomplete) had to be disabled because of the crashes. Now that the crashes
are fixed, the updated test results for v2 reflect the same partial decodes
that OpenJPEG v1.3.0 was performing.

The fix will likely be submitted to the OpenJPEG project tomorrow night,
when I have more time.


Sheet Spotter

-----Original Message-----
From: Robin Cornelius [mailto:robin.cornelius at gmail.com] 
Sent: September 23, 2010 5:37 AM
To: Sheet Spotter
Cc: opensource-dev
Subject: Re: [opensource-dev] Openjpeg/KDU the cold hard metrics

On Thu, Sep 23, 2010 at 3:40 AM, Sheet Spotter <sheet.spotter at gmail.com>
wrote:
> There may be another option for obtaining a common set of J2C files for
> comparison.
>
> Viewer 2 installs 784 JPEG-2000 files (*.j2c) in the "local_assets" folder
> under the main install folder (e.g., "C:\Program
Files\SecondLifeViewer2").
>
> The "j2k_metric" test harness decoded all 784 files from the
"local_assets"
> folder without errors. The OpenJPEG 1.3.0 library was 3.7 times slower
than
> the KDU library that comes with Viewer 2.1.1.208043 (the current release
> version).

Hi (again) Sheet and everyone else,

I've started another sheet with a fresh set of results on another
system of mine, please feel free to add your own tests rows

https://spreadsheets.google.com/ccc?key=0AiSrUP47_VxIdEZ4NmlSY281UXFac0ZZTkV
jWGJtV1E&hl=en&authkey=CIGY9M4O

If you want to compare to KDU you need to compare to KDU on your
system don't compare to by KDU results or anyone elses, thats not a
fair comparision.

OJP 2.0 is not playing nice with the local_asset texture set needs some
work.

Robin



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