jdarith.c


Log

Author Commit Date CI Message
DRC 52fef349 2019-12-10T19:10:55 Eliminate internal use of GETJOCTET() macro Because of 01e30323546d37792e4f682d78d58bb8b3e185ab (officially eliminating support for compilers without unsigned char, since we never effectively supported those compilers anyhow), GETJOCTET() is now a no-op. Since that macro is in jmorecfg.h, it is part of the de facto libjpeg API and must remain in the public headers. However, there is no reason to continue using it internally, and eliminating its internal use improves code readability.
DRC 2234deee 2019-11-08T13:51:34 Fix MSan use-of-uninitialized-value error ... introduced by 42825b68d570fb07fe820ac62ad91017e61e9a25. In fact, fault-tolerant multi-scan block smoothing cannot currently be used with the arithmetic decoder, because that decoder doesn't have any way of distinguishing a normal end of scan from an unexpected end of scan. Thus, this commit also modifies the change log to reset the expectations regarding the scope of the fault-tolerant multi-scan block smoothing feature. If, at some point in the future, the arithmetic decoder can be modified to detect an unexpected end of scan, then one would need only set entropy->pub.insufficient_data = TRUE when the arithmetic decoder encounters an unexpected end of scan in order to make fault-tolerant block smoothing work properly with that decoder.
DRC 42825b68 2019-11-07T14:03:23 Fault-tolerant multi-scan block smoothing This commit modifies the behavior of the block smoothing algorithm in the libjpeg API library so that, if a scan in a multi-scan JPEG image is incomplete (due to premature termination of the image stream), the block smoothing parameters from the previous (complete) scan are used to smooth any iMCU rows that the incomplete scan does not contain. Closes #343
DRC a6289526 2018-07-24T18:36:51 Fix JPEG spec references per ISO/ITU-T suggestions - When referring to specific clauses, annexes, tables, and figures, a "timed reference" (a reference that includes the year) must be used in order to avoid confusion. - "CCITT" = "ITU-T" - Replace ambiguous "JPEG spec" with the specific document number.
DRC 293263c3 2018-03-17T15:14:35 Format preprocessor macros more consistently Within the libjpeg API code, it seems to be more the convention than not to separate the macro name and value by two or more spaces, which improves general readability. Making this consistent across all of libjpeg-turbo is less about my individual preferences and more about making it easy to automatically detect variations from our chosen formatting convention. I intend to release the script I'm using to validate this stuff, once it matures and stabilizes a bit.
DRC 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.
DRC 0e2bca07 2017-12-15T20:37:02 jdarith.c: Fix two signed integer overflows I guess I have to fix these, or Google Autofuzz is going to keep bugging me about them. Fixes #171 Fixes #197 Fixes #198
DRC ac4a8995 2016-09-22T14:38:51 Fix UBSan warning in arithmetic decoder Very similar to the ones that were fixed in the Huffman decoders in 8e9cef2e6f5156c4b055a04a8f979b7291fc6b7a. These are innocuous. Refer to https://bugzilla.mozilla.org/show_bug.cgi?id=1304567.
DRC a1dd3568 2016-09-08T21:29:58 Silence additional UBSan warnings NOTE: The jdhuff.c/jdphuff.c warnings should have already been silenced by 8e9cef2e6f5156c4b055a04a8f979b7291fc6b7a, but apparently I need to be REALLY clear that I'm trying to do pointer arithmetic rather than dereference an array. Grrr... Refer to: https://bugzilla.mozilla.org/show_bug.cgi?id=1301250 https://bugzilla.mozilla.org/show_bug.cgi?id=1301256
DRC e621dfc5 2016-02-19T10:35:09 More minor code formatting tweaks
DRC bd49803f 2016-02-19T08:53:33 Use consistent/modern code formatting for pointers The convention used by libjpeg: type * variable; is not very common anymore, because it looks too much like multiplication. Some (particularly C++ programmers) prefer to tuck the pointer symbol against the type: type* variable; to emphasize that a pointer to a type is effectively a new type. However, this can also be confusing, since defining multiple variables on the same line would not work properly: type* variable1, variable2; /* Only variable1 is actually a pointer. */ This commit reformats the entirety of the libjpeg-turbo code base so that it uses the same code formatting convention for pointers that the TurboJPEG API code uses: type *variable1, *variable2; This seems to be the most common convention among C programmers, and it is the convention used by other codec libraries, such as libpng and libtiff.
DRC 54e6b8e8 2016-02-18T15:16:17 Include some comments/doc tweaks from jpeg-9+
Guido Vollbeding a560e4b4 2016-01-17T00:00:00 The Independent JPEG Group's JPEG software v9b
Guido Vollbeding fc11193e 2014-01-19T00:00:00 The Independent JPEG Group's JPEG software v9a
Guido Vollbeding e7f88aec 2013-01-13T00:00:00 The Independent JPEG Group's JPEG software v9
DRC 1e32fe31 2015-10-14T17:32:39 Replace INT32 with a new internal datatype (JLONG) These days, INT32 is a commonly-defined datatype in system headers. We cannot eliminate the definition of that datatype from jmorecfg.h, since the INT32 typedef has technically been part of the libjpeg API since version 5 (1994.) However, using INT32 internally is risky, because the inclusion of a particular header (Xmd.h, for instance) could change the definition of INT32 from long to int on 64-bit platforms and thus change the internal behavior of libjpeg-turbo in unexpected ways (for instance, failing to correctly set __INT32_IS_ACTUALLY_LONG to match the INT32 typedef-- perhaps as a result of including the wrong version of jpeglib.h-- could cause libjpeg-turbo to produce incorrect results.) The library has always been built in environments in which INT32 is effectively long (on Windows, long is always 32-bit, so effectively it's the same as int), so it makes sense to turn INT32 into an explicitly long datatype. This ensures that libjpeg-turbo will always behave consistently, regardless of the headers included at compile time. Addresses a concern expressed in #26.
DRC 7e3acc0e 2015-10-10T10:25:46 Rename README, LICENSE, BUILDING text files The IJG README file has been renamed to README.ijg, in order to avoid confusion (many people were assuming that that was our project's README file and weren't reading README-turbo.txt) and to lay the groundwork for markdown versions of the libjpeg-turbo README and build instructions.
DRC 60efb896 2015-09-21T13:13:44 Merge branch '1.4.x'
DRC 8e9cef2e 2015-09-21T12:57:41 Fix various issues reported by the UB sanitizers Most of these involved left shifting a negative number, which is technically undefined (although every modern compiler I'm aware of will implement this by treating the signed integer as a 2's complement unsigned integer-- the LEFT_SHIFT() macro just makes this behavior explicit in order to shut up ubsan.) This also fixes a couple of non-issues in the entropy codecs, whereby the sanitizer reported an out-of-bounds index in the 4th argument of jpeg_make_d_derived_tbl(). In those cases, the index was actually out of bounds (caused by a malformed JPEG image), but jpeg_make_d_derived_tbl() would have caught the error and aborted prior to actually using the invalid address. Here again, the fix was to make our intentions explicit so as to shut up ubsan.
Thomas G. Lane 36a4cccc 1994-09-24T00:00:00 The Independent JPEG Group's JPEG software v5
Thomas G. Lane 88aeed42 1992-12-10T00:00:00 The Independent JPEG Group's JPEG software v4
Thomas G. Lane 4a6b7303 1992-03-17T00:00:00 The Independent JPEG Group's JPEG software v3
Thomas G. Lane 2cbeb8ab 1991-10-07T00:00:00 The Independent JPEG Group's JPEG software v1
Guido Vollbeding 1e247ac8 1998-03-28T00:00:00 The Independent JPEG Group's JPEG software v6b with arithmetic coding support
Guido Vollbeding 5829cb23 2012-01-15T00:00:00 The Independent JPEG Group's JPEG software v8d
Guido Vollbeding 989630f7 2010-01-10T00:00:00 The Independent JPEG Group's JPEG software v8
Guido Vollbeding 5996a25e 2009-06-27T00:00:00 The Independent JPEG Group's JPEG software v7
DRC eb32cc1e 2015-06-25T03:44:36 Add a new libjpeg API function (jpeg_skip_scanlines()) to allow for partially decoding a JPEG image. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1582 632fc199-4ca6-4c93-a231-07263d6284db
DRC 5de454b2 2014-05-18T19:04:03 libjpeg-turbo has never supported non-ANSI compilers, so get rid of the crufty SIZEOF() macro. It was not being used consistently anyhow, so it would not have been possible to build prior releases of libjpeg-turbo using the broken compilers for which that macro was designed. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1313 632fc199-4ca6-4c93-a231-07263d6284db
DRC b7753510 2014-05-11T09:36:25 Convert tabs to spaces in the libjpeg code and the SIMD code (TurboJPEG retains the use of tabs for historical reasons. They were annoying in the libjpeg code primarily because they were not consistently used and because they were used to format as well as indent the code. In the case of TurboJPEG, tabs are used just to indent the code, so even if the editor assumes a different tab width, the code will still be readable.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@1285 632fc199-4ca6-4c93-a231-07263d6284db
DRC e5eaf374 2014-05-09T18:00:32 Convert tabs to spaces in the libjpeg code and the SIMD code (TurboJPEG retains the use of tabs for historical reasons. They were annoying in the libjpeg code primarily because they were not consistently used and because they were used to format as well as indent the code. In the case of TurboJPEG, tabs are used just to indent the code, so even if the editor assumes a different tab width, the code will still be readable.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1278 632fc199-4ca6-4c93-a231-07263d6284db
DRC 66f97e68 2010-11-23T05:49:54 Support arithmetic encoding and decoding git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@299 632fc199-4ca6-4c93-a231-07263d6284db