2.1 === * Update documentation to reflect new command line flags and any other relevant changes. Should read through ChangeLog and the manual before releasing 2.1. * Write documentation section on source-level API changes between 2.0 and 2.1. * Really need to get rid of embedded external libs. We can either provide them separately for Windows or provide instructions for building them. Remember to remove -DHAVE_VSNPRINTF from config-msvc and to remove --enable-build-external-libs from both. mingw: for pcre ./configure --disable-shared --disable-cpp --prefix=... make make install for zlib ./conifgure --prefix=... make make install for qpdf CFLAGS="-IC:/path/to/pcre... -IC:/path/to/zlib..." \ LDFLAGS="-LC:/path/to/pcre... -LC:/path/to/zlib..." \ ./configure --disable-test-compare-images --with-buildrules=mingw msvc: * Windows release: config for both compilers, make install. Create zip files. Probably should put the compiler name somewhere in the directory (qpdf-version-compiler?). Need some kind of "what to download" file. * Add comments for the security functions that map them back to the items in Adobe's products. * "Delphi wrapper unit 'qpdf.pas' created by Zarko Gajic (http://delphi.about.com). .. use at your own risk and for whatever the purpose you want .. no support provided. Sample code provided." 2.2 === * Add ability to create new streams or replace stream data. Consider stream data sources to include a file and offset, a buffer, or a some kind of callback mechanism. Find messages exchanged with Stefan Heinsen in August, 2009. He seems to like to send encrypted mail. (key 01FCC336) * Look at page splitting. General ======= * Handle embedded files. PDF Reference 1.7 section 3.10, "File Specifications", discusses this. Once we can definitely recongize all embedded files in a docucment, we can update the encryption code to handle it properly. In QPDF_encryption.cc, search for cf_file. Remove exception thrown if cf_file is different from cf_stream, and write code in the stream decryption section to use cf_file instead of cf_stream. In general, add interfaces to get the list of embedded files and to extract them. To handle general embedded files associated with the whole document, follow root -> /Names -> /EmbeddedFiles -> /Names to get to the file specification dictionaries. Then, in each file specification dictionary, follow /EF -> /F to the actual stream. * The description of Crypt filters is unclear with respect to how to use them to override /StmF for specific streams. I'm not sure whether qpdf will do the right thing for any specific individual streams that might have crypt filters. The specification seems to imply that only embedded file streams and metadata streams can have crypt filters, and there are already special cases in the code to handle those. Most likely, it won't be a problem, but someday someone may find a file that qpdf doesn't work on because of crypt filters. There is an example in the spec of using a crypt filter on a metadata stream. For now, we notice /Crypt filters and decode parameters consistent with the example in the PDF specification, and the right thing happens for metadata filters that happen to be uncompressed or otherwise compressed in a way we can filter. This should handle all normal cases, but it's more or less just a guess since I don't have any test files that actually use stream-specific crypt filters in them. * The second xref stream for linearized files has to be padded only because we need file_size as computed in pass 1 to be accurate. If we were not allowing writing to a pipe, we could seek back to the beginning and fill in the value of /L in the linearization dictionary as an optimization to alleviate the need for this padding. Doing so would require us to pad the /L value individually and also to save the file descriptor and determine whether it's seekable. This is probably not worth bothering with. * The whole xref handling code in the QPDF object allows the same object with more than one generation to coexist, but a lot of logic assumes this isn't the case. Anything that creates mappings only with the object number and not the generation is this way, including most of the interaction between QPDFWriter and QPDF. If we wanted to allow the same object with more than one generation to coexist, which I'm not sure is allowed, we could fix this by changing xref_table. Alternatively, we could detect and disallow that case. In fact, it appears that Adobe reader and other PDF viewing software silently ignores objects of this type, so this is probably not a big deal. * Pl_PNGFilter is only partially implemented. If we ever decoded images, we'd have to finish implementing it along with the other filter decode parameters and types. For just handling xref streams, there's really no need as it wouldn't make sense to use any kind of predictor other than 12 (PNG UP filter). * If we ever want to have check mode check the integrity of the free list, this can be done by looking at the code from prior to the object stream support of 4/5/2008. It's in an if (0) block and there's a comment about it. There's also something about it in qpdf.test -- search for "free table". On the other hand, the value of doing this seems very low since no viewer seems to care, so it's probably not worth it. * QPDFObjectHandle::getPageImages() doesn't notice images in inherited resource dictionaries. See comments in that function. * Based on an idea suggested by user "Atom Smasher", consider providing some mechanism to recover earlier versions of a file embedded prior to appended sections. Splitting by Pages ================== Although qpdf does not currently support splitting a file into pages, the work done for linearization covers almost all the work. To do page splitting. If this functionality is needed, study obj_user_to_objects and object_to_obj_users created in QPDF_optimization for ideas. It's quite possible that the information computed by calculateLinearizationData is actually sufficient to do page splitting in many circumstances. That code knows which objects are used by which pages, though it doesn't do anything page-specific with outlines, thumbnails, page labels, or anything else. Another approach would be to traverse only pages that are being output taking care not to traverse into the pages tree, and then to fabricate a new pages tree. Either way, care must be taken to handle other things such as outlines, page labels, thumbnails, threads, zones, etc. in a sensible way. This may include simply omitting information other than page content.