Bug 691868

Summary: DCTEncode filter crashes Ghostscript if QuantTables parameter specified
Product: Ghostscript Reporter: Paul Tribick <ptribick>
Component: ImagesAssignee: Alex Cherepanov <alex>
Status: RESOLVED FIXED    
Severity: normal    
Priority: P4    
Version: 8.71   
Hardware: PC   
OS: Windows XP   
Customer: Word Size: ---
Attachments: patch

Description Paul Tribick 2011-01-05 23:26:13 UTC 
When using the DCTEncode filter, Ghostscript crashes if the QuantTables parameter is specified. Adobe Distiller 6.0 is happy with the code.

If QuantTables parameter is removed (ie using default tables), Ghostscript is happy.

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Edited code example (incomplete):

/DataSource { ... } def % provides one row of image data,
                        % ie SamplesPerPixel * ImageWidth bytes

/QTable1 	<0302020302020303030304030304050805050404050A070706080C0A0C0C0B0A0B0B0D0E12100D0E110E0B0B1016101113141515150C0F171816141812141514> def
/QTable2	<03040405040509050509140D0B0D1414141414141414141414141414141414141414141414141414141414141414141414141414141414141414141414141414> def

/SamplesPerPixel 3 def  % Or 1 for B&W

(DCTEncode_temp.jpg) (w) file
<<	/Columns	ImageWidth
	/Rows		ImageHeight
	/Colors		SamplesPerPixel
	/QFactor	1.0
	/QuantTables	[ QTable1 SamplesPerPixel 1 sub { QTable2 } repeat ]
>> /DCTEncode filter
ImageHeight { dup DataSource writestring } repeat
closefile
% ...

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Comment 1 Alex Cherepanov 2011-01-06 00:58:07 UTC 
Please attach a full sample.
Comment 2 Alex Cherepanov 2011-01-06 17:56:42 UTC 
The sample code is good enough. The problem is reproduced.
Thank you for using and testing Ghostscript.
Comment 3 Alex Cherepanov 2011-01-06 19:17:06 UTC 
Created attachment 7096 [details]
patch

Fix a cut-ant-paste error in setting QuantTables for JPXEncode filter.
Comment 4 Alex Cherepanov 2011-01-06 19:19:48 UTC 
The patch has been committed as a rev. 12003.