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bigboss djo
bigboss djo
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haw i get the last trailer?

Jul 27, 2012 3:02 AM

Tags: #trailer

i start from the end of the document, then i read the startxref and locate the xref, then i parse the crossrefrence and get the trailer.

i dot this operation recursively  but when i finish my parse haw i know the last trailer?

so i compare the  size value of all trailer and i choose the trailer having max size?

943 Views   8 Replies   Latest reply: bigboss djo, Jul 27, 2012 5:57 AM
 
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  • Karl Heinz Kremer
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    1. Karl Heinz Kremer,
    Jul 27, 2012 5:05 AM   in reply to bigboss djo
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    I don't quite understand what you are asking.

    Are you asking how to determine that you've reached the first (and

    original) trailer dictionary in a file with incremental updates? If so,

    it's the trailer that does not have a Prev entry. If that's not the answer

    to your question, can you please try to rephrase your question.

     

    Karl Heinz Kremer

    PDF Acrobatics Without a Net

     

    khk@khk.net

    http://www.khkonsulting.com

     
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  • bigboss djo
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    2. bigboss djo,
    Jul 27, 2012 5:15 AM   in reply to Karl Heinz Kremer
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    i not talk about the original trailer does not have a Prev entry, but i talk about the last trailer added it in document.

    because the last trailer can't be the last writed in the end of document , it can be write in first document, thats why it difficult to know the last of trailer

     
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  • Karl Heinz Kremer
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    3. Karl Heinz Kremer,
    Jul 27, 2012 5:18 AM   in reply to bigboss djo
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    Incremental updates only append to the document, so you would look at the

    end of your file. The trailer that you find there is the last incremental

    update that was applied to that document.

     

    If you want another way to identify it, it's the one that no Prev entry of

    any of the other trailer sections point to.

     

    Karl Heinz Kremer

    PDF Acrobatics Without a Net

     

    khk@khk.net

    http://www.khkonsulting.com

     
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  • bigboss djo
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    4. bigboss djo,
    Jul 27, 2012 5:27 AM   in reply to Karl Heinz Kremer
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    Not every time that the Incremental updates only append to the document, because i have  %PDF-1.5 a pdf that contains the original trailer in the end and the new Trailer in begin of document. and this is can make me a big problem when i try to parse and find all subsection and the lat trailer

     
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  • lrosenth
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    5. lrosenth,
    Jul 27, 2012 5:33 AM   in reply to bigboss djo
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    That trailer at the beginning is the linearization table.  See the relevant Annex in ISO 32000-1:2008

     
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  • bigboss djo
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    6. bigboss djo,
    Jul 27, 2012 5:53 AM   in reply to lrosenth
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    but haw i can i parse the document if i have linearization table.?because i have an original trailer at the end file and stream cross referecne and linear trailer in the first?

     
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  • lrosenth
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    7. lrosenth,
    Jul 27, 2012 5:54 AM   in reply to bigboss djo
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    Ignore the linearization table – just as described in ISO 32000-1:2008.  You have read that, right??

     
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  • bigboss djo
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    8. bigboss djo,
    Jul 27, 2012 5:57 AM   in reply to lrosenth
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    you talk about this part?

    7.5.8.4Compatibility with Applications That Do Not Support Compressed Reference Streams

     
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