MantisBT - ParaView
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IDProjectCategoryView StatusDate SubmittedLast Update
0011989ParaViewBugpublic2011-03-19 04:482016-08-12 09:58
ReporterFlorian Kummer 
Assigned ToCory Quammen 
PrioritynormalSeverityminorReproducibilityalways
StatusclosedResolutionmoved 
Platformx86OSWindowsOS Version7
Product Version3.8.1 
Target VersionFixed in Version 
Project
Topic Name
Type
Summary0011989: Base64 encoding of VTK output
DescriptionMaybe the Base64 - encoding/decoding is not standart-conform?

As far as I understood, the decoded stream is in the format
{int n, float d[0], ... , float d[n-1]}

I exported a very simple example with Paraview;
I'm able to decode the floats, but the leading integer is just wrong;
I'm pretty sure that my decoder works correctly, because it decodes some example from wikipedia (http://de.wikipedia.org/wiki/Base64#Beispiel [^]) correctly,
as well as it decodes the floats correctly;
Steps To ReproduceLoad attached file test-ascii.vtr in Paraview, and save data as Rectilinear VTK, binary, no compression;

Open the new file, copy and paste some of the strings to the program VTR_Demo_.c (i've allready done that)

Compile the attached program VTR_Demo_.c;
In line 138, 141, 144 you'll find three examples of Base64-Encoded data, allways two of them commented out;
One is a reference (from http://de.wikipedia.org/wiki/Base64#Beispiel [^]), and the other two's came from the Paravie VTR export;

Run the Program, on the output you will see the leading integer of the data stream, as well as the next three floats;
The integer is wrong;
Additional Information
TagsNo tags attached.
Relationships
Attached Files? test-ascii.vtr (963) 2011-03-19 04:48
https://www.vtk.org/Bug/file/8761/test-ascii.vtr
? test-binary.vtr (1,053) 2011-03-19 04:49
https://www.vtk.org/Bug/file/8762/test-binary.vtr
c VTR_Demo_.c (6,739) 2011-03-19 04:50
https://www.vtk.org/Bug/file/8763/VTR_Demo_.c
Issue History
Date ModifiedUsernameFieldChange
2011-03-19 04:48Florian KummerNew Issue
2011-03-19 04:48Florian KummerFile Added: test-ascii.vtr
2011-03-19 04:49Florian KummerFile Added: test-binary.vtr
2011-03-19 04:50Florian KummerFile Added: VTR_Demo_.c
2011-03-20 15:13Robert MaynardNote Added: 0025834
2011-03-20 16:07Robert MaynardNote Edited: 0025834bug_revision_view_page.php?bugnote_id=25834#r257
2016-07-25 12:59Cory QuammenNote Added: 0036558
2016-07-25 12:59Cory QuammenStatusbacklog => closed
2016-07-25 12:59Cory QuammenAssigned To => Cory Quammen
2016-07-25 12:59Cory QuammenResolutionopen => no change required
2016-07-25 22:25Cory QuammenStatusclosed => backlog
2016-07-25 22:25Cory QuammenResolutionno change required => reopened
2016-07-25 22:28Cory QuammenNote Added: 0036597
2016-07-25 22:28Cory QuammenStatusbacklog => customer review
2016-07-25 22:28Cory QuammenResolutionreopened => fixed
2016-08-12 09:58Kitware RobotNote Added: 0037940
2016-08-12 09:58Kitware RobotStatuscustomer review => closed
2016-08-12 09:58Kitware RobotResolutionfixed => moved

Notes
(0025834)
Robert Maynard   
2011-03-20 15:13   
(edited on: 2011-03-20 16:07)
You should read how the binary format is constructed on this wiki page:
http://www.vtk.org/Wiki/VTK_XML_Formats [^]

The integer doesn't represent the length, the length is derived from the extents and the spacing.

EDIT:
Off the top of my head I don't know what the first integer represents when use base64 encoding.
(0036558)
Cory Quammen   
2016-07-25 12:59   
There does not appear to be a problem writing with base64 encoding and then reading the file within ParaView itself.
(0036597)
Cory Quammen   
2016-07-25 22:28   
To test:

Start ParaView, local server
Open the attached file test-ascii.vtr
Save the data set with binary encoding to another file name, choose Encode Appended Data
Reopen the data set
All works fine

I don't know what the first integer is, but as far as ParaView is concerned the writer and reader with Base64 encoding works fine.
(0037940)
Kitware Robot   
2016-08-12 09:58   
Resolving issue as `moved`.

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