The clarification is that the PDF References aren't "normative" in nature - they don't (usually) make final, definitive statements - just sort of general ones. The end of file is more specified in this case, but the beginning is not (IIRC).
Leonard On Dec 14, 2008, at 3:06 PM, Michael Klink wrote: > Leonard, > > when looking at the PDF 1.7 spec, I find descriptions that to me > look very much like those in the ISO specifications. > > Section 3.4.4 states: > > "The last line of the file contains only the end-of-file marker, % > %EOF. (See implementation note 18 in Appendix H.)" > > The referenced implementation note states > > "Acrobat viewers require only that the %%EOF marker appear somewhere > within the last 1024 bytes of the file." > > To me this looks very much like the ISO specification in combination > with the new implementation notes. This eventually would mean, that > according to the Adobe PDF 1.7 specification, too, rubbish is not > allowed, merely tolerated by Adobe viewers. As far as I remember > former Adobe PDF specification contained wordings here to the same > effect... > > Or had there been some clarification stating something different? > > Regards, Michael. > > -----Ursprüngliche Nachricht----- > Von: Leonard Rosenthol [mailto:[email protected]] > Gesendet: Sonntag, 14. Dezember 2008 00:03 > An: Post all your questions about iText here > Betreff: Re: [iText-questions] PJL commands in pdf files: OK? > > The ability to have "rubbish" at the start or end of the PDF was one > of the things that was done during the Adobe->ISO transition of PDF > 1.7 to ISO 32000 to tighten down the PDF file format for the future. > > So while a file with such 'rubbish' is PDF 1.7 compliant, for example, > it is NOT ISO 32000 compliant. And as noted, Adobe Acrobat/Reader are > able to properly consume the file. HOWEVER, like iText, any such > 'rubbish' is tossed during processing. > > Leonard > > On Dec 13, 2008, at 1:04 PM, Michael Klink wrote: > >>> "Some" rubbish is allowed at the end of the PDF file, but not too >>> much. >> >> Actually no rubbish at all is allowed by the PDF standard itself. >> According to specification (ISO 32000-1:2008 Abschnitt 7.5.5, >> ähnlich in früheren PDF-Spezifikationen) the %%EOF-line has to be >> the final one of the document: >> >> "The last line of the file shall contain only the end-of-file >> marker, %%EOF." >> >>> From the top of my head, I'd say you may not have more than 1028 >>> bytes >>> of rubbish, BUT you should check that number AND different viewers >>> will >>> have a different tolerance. >> >> Adobe Acrobat and Reader are a bit lax about these specification >> parts. The Acrobat 9 implementation notes state: >> >> "Acrobat viewers require only that the %%EOF marker appear somewhere >> within the last 1024 bytes of the file." >> >> Some people utilize this leniency to add some own data to PDF >> documents. >> >> This does not imply, though, that this is in accordance to >> specification. Strictly speaking, such PDF files are broken. > > -- > Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit > allen: http://www.gmx.net/de/go/multimessenger > > ------------------------------------------------------------------------------ > SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, > Nevada. > The future of the web can't happen without you. Join us at MIX09 to > help > pave the way to the Next Web now. Learn more and register at > http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ > _______________________________________________ > iText-questions mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/itext-questions > > Buy the iText book: http://www.1t3xt.com/docs/book.php > ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ iText-questions mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.1t3xt.com/docs/book.php
