Short feedback on that topic. The JPEG specs seem to require all XMP tags to fit into one single 64k segment. Splitting it up would violate that standard and potentially make the file incompatible.
One learning is that for JPEG outputs we can not guarantee to include an arbitrarily sized XMP block. Users should therefore not rely on exported JPEGS as a fallback for sidecar files. This needs to be made clear in the user manual. Mid term we should consider to store certain XMP data in a compressed form. Namely the vector data describing brush masks can consume a lot of space. Currently all binary data is stored - not very efficiently - as printable hexadecimal. We could save a lot of space if we store them in a gzip+base64 format. Ulrich Am 26.09.2013 12:57, schrieb Dimitrios Psychogios: > From a cursory websearch it looks like this is not possible in the > standard APP1 segment normally used for XMP data. You should be able to > use multiple APP2 segments which i believe are also used for ICC profile > data (which are usually >64K). Some sample code I found is here: > http://src.chromium.org/svn/trunk/src/third_party/iccjpeg/iccjpeg.c > > ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60133471&iu=/4140/ostg.clktrk _______________________________________________ darktable-devel mailing list darktable-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-devel
