kmx git

Commit	Date	Message
e8b40f3c	2022-11-01T21:45:39	Vastly improve 12-bit JPEG integration The Gordian knot that 7fec5074f962b20ed00b4f5da4533e1e8d4ed8ac attempted to unravel was caused by the fact that there are several data-precision-dependent (JSAMPLE-dependent) fields and methods in the exposed libjpeg API structures, and if you change the exposed libjpeg API structures, then you have to change the whole API. If you change the whole API, then you have to provide a whole new library to support the new API, and that makes it difficult to support multiple data precisions in the same application. (It is not impossible, as example.c demonstrated, but using data-precision-dependent libjpeg API structures would have made the cjpeg, djpeg, and jpegtran source code hard to read, so it made more sense to build, install, and package 12-bit-specific versions of those applications.) Unfortunately, the result of that initial integration effort was an unreadable and unmaintainable mess, which is a problem for a library that is an ISO/ITU-T reference implementation. Also, as I dug into the problem of lossless JPEG support, I realized that 16-bit lossless JPEG images are a thing, and supporting yet another version of the libjpeg API just for those images is untenable. In fact, however, the touch points for JSAMPLE in the exposed libjpeg API structures are minimal: - The colormap and sample_range_limit fields in jpeg_decompress_struct - The alloc_sarray() and access_virt_sarray() methods in jpeg_memory_mgr - jpeg_write_scanlines() and jpeg_write_raw_data() - jpeg_read_scanlines() and jpeg_read_raw_data() - jpeg_skip_scanlines() and jpeg_crop_scanline() (This is subtle, but both of those functions use JSAMPLE-dependent opaque structures behind the scenes.) It is much more readable and maintainable to provide 12-bit-specific versions of those six top-level API functions and to document that the aforementioned methods and fields must be type-cast when using 12-bit samples. Since that eliminates the need to provide a 12-bit-specific version of the exposed libjpeg API structures, we can: - Compile only the precision-dependent libjpeg modules (the coefficient buffer controllers, the colorspace converters, the DCT/IDCT managers, the main buffer controllers, the preprocessing and postprocessing controller, the downsampler and upsamplers, the quantizers, the integer DCT methods, and the IDCT methods) for multiple data precisions. - Introduce 12-bit-specific methods into the various internal structures defined in jpegint.h. - Create precision-independent data type, macro, method, field, and function names that are prefixed by an underscore, and use an internal header to convert those into precision-dependent data type, macro, method, field, and function names, based on the value of BITS_IN_JSAMPLE, when compiling the precision-dependent libjpeg modules. - Expose precision-dependent jinit() functions for each of the precision-dependent libjpeg modules. - Abstract the precision-dependent libjpeg modules by calling the appropriate precision-dependent jinit() function, based on the value of cinfo->data_precision, from top-level libjpeg API functions.
5acd9f20	2022-10-04T12:58:11	Merge branch 'main' into dev
eb0a024a	2022-10-04T12:51:38	Remove redundant jconfigint.h #includes Because of 607b668ff96e40fdc749de9b1bb98e7f40c86d93, jconfigint.h is included by jinclude.h.
7fec5074	2022-03-08T12:34:11	Support 8-bit & 12-bit JPEGs using the same build Partially implements #199 This commit also implements a request from #178 (the ability to compile the libjpeg example as a standalone program.)
19c791cd	2018-03-08T10:55:20	Improve code formatting consistency With rare exceptions ... - Always separate line continuation characters by one space from preceding code. - Always use two-space indentation. Never use tabs. - Always use K&R-style conditional blocks. - Always surround operators with spaces, except in raw assembly code. - Always put a space after, but not before, a comma. - Never put a space between type casts and variables/function calls. - Never put a space between the function name and the argument list in function declarations and prototypes. - Always surround braces ('{' and '}') with spaces. - Always surround statements (if, for, else, catch, while, do, switch) with spaces. - Always attach pointer symbols ('' and '') to the variable or function name. - Always precede pointer symbols ('' and '**') by a space in type casts. - Use the MIN() macro from jpegint.h within the libjpeg and TurboJPEG API libraries (using min() from tjutil.h is still necessary for TJBench.) - Where it makes sense (particularly in the TurboJPEG code), put a blank line after variable declaration blocks. - Always separate statements in one-liners by two spaces. The purpose of this was to ease maintenance on my part and also to make it easier for contributors to figure out how to format patch submissions. This was admittedly confusing (even to me sometimes) when we had 3 or 4 different style conventions in the same source tree. The new convention is more consistent with the formatting of other OSS code bases. This commit corrects deviations from the chosen formatting style in the libjpeg API code and reformats the TurboJPEG API code such that it conforms to the same standard. NOTES: - Although it is no longer necessary for the function name in function declarations to begin in Column 1 (this was historically necessary because of the ansi2knr utility, which allowed libjpeg to be built with non-ANSI compilers), we retain that formatting for the libjpeg code because it improves readability when using libjpeg's function attribute macros (GLOBAL(), etc.) - This reformatting project was accomplished with the help of AStyle and Uncrustify, although neither was completely up to the task, and thus a great deal of manual tweaking was required. Note to developers of code formatting utilities: the libjpeg-turbo code base is an excellent test bed, because AFAICT, it breaks every single one of the utilities that are currently available. - The legacy (MMX, SSE, 3DNow!) assembly code for i386 has been formatted to match the SSE2 code (refer to ff5685d5344273df321eb63a005eaae19d2496e3.) I hadn't intended to bother with this, but the Loongson MMI implementation demonstrated that there is still academic value to the MMX implementation, as an algorithmic model for other 64-bit vector implementations. Thus, it is desirable to improve its readability in the same manner as that of the SSE2 implementation.
aa745905	2017-11-16T18:09:07	TurboJPEG C API: Add BMP/PPM load/save functions The main justification for this is to provide new libjpeg-turbo users with a quick & easy way of developing a complete JPEG compression/decompression program without requiring them to build libjpeg-turbo from source (which was necessary in order to use the project-private bmp API) or to use external libraries. These new functions build upon significant enhancements to rdbmp.c, wrbmp.c, rdppm.c, and wrppm.c which allow those engines to convert directly between the native pixel format of the file and a pixel format ("colorspace" in libjpeg parlance) specified by the calling program. rdbmp.c and wrbmp.c have also been modified such that the calling program can choose to read or write image rows in the native (bottom-up) order of the file format, thus eliminating the need to use an inversion array. tjLoadImage() and tjSaveImage() leverage these new underlying features in order to significantly improve upon the performance of the old bmp API. Because these new functions cannot work without the libjpeg-turbo colorspace extensions, the libjpeg-compatible code in turbojpeg.c has been removed. That code was only there to serve as an example of how to use the TurboJPEG API on top of libjpeg, but more specific, buildable examples now exist in the https://github.com/libjpeg-turbo/ijg repository.

e8b40f3c

2022-11-01T21:45:39

Vastly improve 12-bit JPEG integration The Gordian knot that 7fec5074f962b20ed00b4f5da4533e1e8d4ed8ac attempted to unravel was caused by the fact that there are several data-precision-dependent (JSAMPLE-dependent) fields and methods in the exposed libjpeg API structures, and if you change the exposed libjpeg API structures, then you have to change the whole API. If you change the whole API, then you have to provide a whole new library to support the new API, and that makes it difficult to support multiple data precisions in the same application. (It is not impossible, as example.c demonstrated, but using data-precision-dependent libjpeg API structures would have made the cjpeg, djpeg, and jpegtran source code hard to read, so it made more sense to build, install, and package 12-bit-specific versions of those applications.) Unfortunately, the result of that initial integration effort was an unreadable and unmaintainable mess, which is a problem for a library that is an ISO/ITU-T reference implementation. Also, as I dug into the problem of lossless JPEG support, I realized that 16-bit lossless JPEG images are a thing, and supporting yet another version of the libjpeg API just for those images is untenable. In fact, however, the touch points for JSAMPLE in the exposed libjpeg API structures are minimal: - The colormap and sample_range_limit fields in jpeg_decompress_struct - The alloc_sarray() and access_virt_sarray() methods in jpeg_memory_mgr - jpeg_write_scanlines() and jpeg_write_raw_data() - jpeg_read_scanlines() and jpeg_read_raw_data() - jpeg_skip_scanlines() and jpeg_crop_scanline() (This is subtle, but both of those functions use JSAMPLE-dependent opaque structures behind the scenes.) It is much more readable and maintainable to provide 12-bit-specific versions of those six top-level API functions and to document that the aforementioned methods and fields must be type-cast when using 12-bit samples. Since that eliminates the need to provide a 12-bit-specific version of the exposed libjpeg API structures, we can: - Compile only the precision-dependent libjpeg modules (the coefficient buffer controllers, the colorspace converters, the DCT/IDCT managers, the main buffer controllers, the preprocessing and postprocessing controller, the downsampler and upsamplers, the quantizers, the integer DCT methods, and the IDCT methods) for multiple data precisions. - Introduce 12-bit-specific methods into the various internal structures defined in jpegint.h. - Create precision-independent data type, macro, method, field, and function names that are prefixed by an underscore, and use an internal header to convert those into precision-dependent data type, macro, method, field, and function names, based on the value of BITS_IN_JSAMPLE, when compiling the precision-dependent libjpeg modules. - Expose precision-dependent jinit*() functions for each of the precision-dependent libjpeg modules. - Abstract the precision-dependent libjpeg modules by calling the appropriate precision-dependent jinit*() function, based on the value of cinfo->data_precision, from top-level libjpeg API functions.

5acd9f20

2022-10-04T12:58:11

Merge branch 'main' into dev

eb0a024a

2022-10-04T12:51:38

Remove redundant jconfigint.h #includes Because of 607b668ff96e40fdc749de9b1bb98e7f40c86d93, jconfigint.h is included by jinclude.h.

7fec5074

2022-03-08T12:34:11

Support 8-bit & 12-bit JPEGs using the same build Partially implements #199 This commit also implements a request from #178 (the ability to compile the libjpeg example as a standalone program.)

19c791cd

2018-03-08T10:55:20

Improve code formatting consistency With rare exceptions ... - Always separate line continuation characters by one space from preceding code. - Always use two-space indentation. Never use tabs. - Always use K&R-style conditional blocks. - Always surround operators with spaces, except in raw assembly code. - Always put a space after, but not before, a comma. - Never put a space between type casts and variables/function calls. - Never put a space between the function name and the argument list in function declarations and prototypes. - Always surround braces ('{' and '}') with spaces. - Always surround statements (if, for, else, catch, while, do, switch) with spaces. - Always attach pointer symbols ('*' and '**') to the variable or function name. - Always precede pointer symbols ('*' and '**') by a space in type casts. - Use the MIN() macro from jpegint.h within the libjpeg and TurboJPEG API libraries (using min() from tjutil.h is still necessary for TJBench.) - Where it makes sense (particularly in the TurboJPEG code), put a blank line after variable declaration blocks. - Always separate statements in one-liners by two spaces. The purpose of this was to ease maintenance on my part and also to make it easier for contributors to figure out how to format patch submissions. This was admittedly confusing (even to me sometimes) when we had 3 or 4 different style conventions in the same source tree. The new convention is more consistent with the formatting of other OSS code bases. This commit corrects deviations from the chosen formatting style in the libjpeg API code and reformats the TurboJPEG API code such that it conforms to the same standard. NOTES: - Although it is no longer necessary for the function name in function declarations to begin in Column 1 (this was historically necessary because of the ansi2knr utility, which allowed libjpeg to be built with non-ANSI compilers), we retain that formatting for the libjpeg code because it improves readability when using libjpeg's function attribute macros (GLOBAL(), etc.) - This reformatting project was accomplished with the help of AStyle and Uncrustify, although neither was completely up to the task, and thus a great deal of manual tweaking was required. Note to developers of code formatting utilities: the libjpeg-turbo code base is an excellent test bed, because AFAICT, it breaks every single one of the utilities that are currently available. - The legacy (MMX, SSE, 3DNow!) assembly code for i386 has been formatted to match the SSE2 code (refer to ff5685d5344273df321eb63a005eaae19d2496e3.) I hadn't intended to bother with this, but the Loongson MMI implementation demonstrated that there is still academic value to the MMX implementation, as an algorithmic model for other 64-bit vector implementations. Thus, it is desirable to improve its readability in the same manner as that of the SSE2 implementation.

aa745905

2017-11-16T18:09:07

TurboJPEG C API: Add BMP/PPM load/save functions The main justification for this is to provide new libjpeg-turbo users with a quick & easy way of developing a complete JPEG compression/decompression program without requiring them to build libjpeg-turbo from source (which was necessary in order to use the project-private bmp API) or to use external libraries. These new functions build upon significant enhancements to rdbmp.c, wrbmp.c, rdppm.c, and wrppm.c which allow those engines to convert directly between the native pixel format of the file and a pixel format ("colorspace" in libjpeg parlance) specified by the calling program. rdbmp.c and wrbmp.c have also been modified such that the calling program can choose to read or write image rows in the native (bottom-up) order of the file format, thus eliminating the need to use an inversion array. tjLoadImage() and tjSaveImage() leverage these new underlying features in order to significantly improve upon the performance of the old bmp API. Because these new functions cannot work without the libjpeg-turbo colorspace extensions, the libjpeg-compatible code in turbojpeg.c has been removed. That code was only there to serve as an example of how to use the TurboJPEG API on top of libjpeg, but more specific, buildable examples now exist in the https://github.com/libjpeg-turbo/ijg repository.

kc3-lang/libjpeg-turbo/cmyk.h

cmyk.h

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