src/jstdhuff.c


Log

Author Commit Date CI Message
DRC 6da05150 2024-10-24T13:25:10 Allow disabling prog/opt/lossless if prev. enabled - Due to an oversight, a113506d175d03ae0e40965c3d3d21a5d561e119 (libjpeg-turbo 1.4 beta1) effectively made the call to std_huff_tables() in jpeg_set_defaults() a no-op if the Huffman tables were previously defined, which made it impossible to disable Huffman table optimization or progressive mode if they were previously enabled in the same API instance. std_huff_tables() retains its previous behavior for decompression instances, but it now force-enables the standard (baseline) Huffman tables for compression instances. - Due to another oversight, there was no way to disable lossless mode if it was previously enabled in a particular API instance. jpeg_set_defaults() now accomplishes this, which makes TJ*PARAM_LOSSLESS behave as intended/documented. - Due to yet another oversight, setCompDefaults() in the TurboJPEG API library permanently modified the value of TJ*PARAM_SUBSAMP when generating a lossless JPEG image, which affected subsequent lossy compression operations. This issue was hidden by the issue above and thus does not need to be publicly documented. Fixes #792
DRC e69dd40c 2024-01-23T13:26:41 Reorganize source to make things easier to find - Move all libjpeg documentation, except for README.ijg, into the doc/ subdirectory. - Move the TurboJPEG C API documentation from doc/html/ into doc/turbojpeg/. - Move all C source code and headers into a src/ subdirectory. - Move turbojpeg-jni.c into the java/ subdirectory. Referring to #226, there is no ideal solution to this problem. A semantically ideal solution would have involved placing all source code, including the SIMD and Java source code, under src/ (or perhaps placing C library source code under lib/ and C test program source code under test/), all header files under include/, and all documentation under doc/. However: - To me it makes more sense to have separate top-level directories for each language, since the SIMD extensions and the Java API are technically optional features. src/ now contains only the code that is relevant to the core C API libraries and associated programs. - I didn't want to bury the java/ and simd/ directories or add a level of depth to them, since both directories already contain source code that is 3-4 levels deep. - I would prefer not to separate the header files from the C source code, because: 1. It would be disruptive. libjpeg and libjpeg-turbo have historically placed C source code and headers in the same directory, and people who are familiar with both projects (self included) are used to looking for the headers in the same directory as the C source code. 2. In terms of how the headers are used internally in libjpeg-turbo, the distinction between public and private headers is a bit fuzzy. - It didn't make sense to separate the test source code from the library source code, since there is not a clear distinction in some cases. (For instance, the IJG image I/O functions are used by cjpeg and djpeg as well as by the TurboJPEG API.) This solution is minimally disruptive, since it keeps all C source code and headers together and keeps java/ and simd/ as top-level directories. It is a bit awkward, because java/ and simd/ technically contain source code, even though they are not under src/. However, other solutions would have been more awkward for different reasons. Closes #226