Loading JPEG images in parallel

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porridge
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Joined: 2014-04-25T13:52:28-07:00
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Re: Loading JPEG images in parallel

Post by porridge »

FTR, the reason there is no thread support on my system turned out to be...

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$ rgrep JPEG_LIB_VERSION /usr/include/
[...]
/usr/include/x86_64-linux-gnu/jconfig.h:#define JPEG_LIB_VERSION 62
$ dpkg -S /usr/include/x86_64-linux-gnu/jconfig.h 
libjpeg62-turbo-dev:amd64: /usr/include/x86_64-linux-gnu/jconfig.h
because in the so called meantime Debian switched to libjpeg-turbo, which exports a smaller JPEG_LIB_VERSION.

So I'm back to square one, trying to determine libjpeg62-turbo's thread safety guarantees are. :?
porridge
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Joined: 2014-04-25T13:52:28-07:00
Authentication code: 6789

Re: Loading JPEG images in parallel

Post by porridge »

I have confirmed that any version of libjpeg-turbo is as thread-safe as libjpeg8.

Given that, how would you feel about changing the following lines in coders/jpeg.c:

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#if JPEG_LIB_VERSION < 80
to something like the following?

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#if JPEG_LIB_VERSION < 80 && !defined(LIBJPEG_TURBO_VERSION)
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magick
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Joined: 2003-05-31T11:32:55-07:00

Re: Loading JPEG images in parallel

Post by magick »

We'll get your patch into ImageMagick 6.9.0-3 Beta by sometime tomorrow.
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