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e8b40f3c
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2022-11-01T21:45:39
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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.
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b579fc11
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2022-02-07T15:27:50
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Eliminate unnecessary JFREAD()/JFWRITE() macros
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17297239
|
2022-01-06T09:17:30
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Eliminate non-ANSI C compatibility macros
libjpeg-turbo has never supported non-ANSI C compilers. Per the spec,
ANSI C compilers must have locale.h, stddef.h, stdlib.h, memset(),
memcpy(), unsigned char, and unsigned short. They must also handle
undefined structures.
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73eff6ef
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2021-11-30T15:06:54
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cjpeg: auto. compr. gray BMP/GIF-->grayscale JPEG
aa7459050d7a50e1d8a99488902d41fbc118a50f was supposed to enable this for
BMP input images but didn't, due to a similar oversight to the one fixed
in the previous commit.
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171b875b
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2021-04-15T19:03:53
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OSS-Fuzz: Check img size b4 readers allocate mem
After the completion of the start_input() method, it's too late to check
the image size, because the image readers may have already tried to
allocate memory for the image. If the width and height are excessively
large, then attempting to allocate memory for the image could slow
performance or lead to out-of-memory errors prior to the fuzz target
checking the image size.
NOTE: Specifically, the aforementioned OOM errors and slow units were
observed with the compression fuzz targets when using MSan.
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ebaa67ea
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2021-04-12T10:38:52
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rdbmp.c: Fix more innocuous UBSan errors
- Referring to 3311fc00010c6cb305d87525c9ef60ebdf036cfc, we need to use
unsigned intermediate math in order to make UBSan happy, even though
(JDIMENSION)(A * B) is effectively the same as
(JDIMENSION)A *(JDIMENSION)B, regardless of intermediate overflow.
- Because of the previous commit, it is now possible for bfOffBits to be
INT_MIN, which would cause the initial computation of bPad to
underflow a signed integer. Thus, we need to check for that
possibility as soon as we know the values of bfOffBits and headerSize.
The worst case from this regression is that bPad could wrap around to
a large positive value, which would cause a "Premature end of input
file" error in the subsequent read_byte() loop. Thus, this issue was
effectively innocuous as well, since it resulted in catching the same
error later and in a different way. Also, the issue was very
well-contained, since it was both introduced and fixed as part of the
ongoing OSS-Fuzz integration project.
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dd830b3f
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2021-04-09T17:36:41
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rdbmp.c/rdppm.c: Fix more innocuous UBSan errors
- rdbmp.c: Because of 8fb37b81713a0cdc14622dc08892ebd28a3233aa,
bfOffBits, biClrUsed, and headerSize were made into unsigned ints.
Thus, if bPad would eventually be negative due to a malformed header,
UBSan complained about unsigned math being used in the intermediate
computations. It was unnecessary to make those variables unsigned,
since they are only meant to hold small values, so this commit makes
them signed again. The UBSan error was innocuous, because it is
effectively (if not officially) the case that
(int)((unsigned int)a - (unsigned int)b) == (int)a - (int)b.
- rdbmp.c: If (biWidth * source->bits_per_pixel / 8) would overflow an
unsigned int, then UBSan complained at the point at which row_width
was set in start_input_bmp(), even though the overflow would have been
detected later in the function. This commit adds overflow checks
prior to setting row_width.
- rdppm.c: read_pbm_integer() now bounds-checks the intermediate
value computations in order to catch integer overflow caused by a
malformed text PPM. It's possible, though extremely unlikely, that
the intermediate value computations could have wrapped around to a
value smaller than maxval, but the worst case is that this would have
generated a bogus pixel in the uncompressed image rather than throwing
an error.
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3311fc00
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2021-04-07T14:20:49
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rdbmp.c: Fix innocuous UBSan error
A fuzzing test case with an image width of 838860946 triggered a UBSan
error:
rdbmp.c:633:34: runtime error: signed integer overflow:
838860946 * 3 cannot be represented in type 'int'
Because the result is cast to an unsigned int (JDIMENSION), this error
is irrelevant, because
(unsigned int)((int)838860946 * (int)3) ==
(unsigned int)838860946 * (unsigned int)3
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88ae6098
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2020-10-27T13:28:56
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Merge branch 'ijg' into dev
- Restore GIF read/compressed GIF write support from jpeg-6a and
jpeg-9d.
- Integrate jpegtran -wipe and -drop options from jpeg-9a and jpeg-9d.
- Integrate jpegtran -crop extension (for expanding the image size) from
jpeg-9a and jpeg-9d.
- Integrate other minor code tweaks from jpeg-9*
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9fc018fd
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2020-01-12T00:00:00
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The Independent JPEG Group's JPEG software v9d
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96e4e7eb
|
2018-01-14T00:00:00
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The Independent JPEG Group's JPEG software v9c
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01e30323
|
2019-01-23T14:58:24
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Eliminate support for compilers w/o unsigned char
libjpeg-turbo has never really supported such compilers, since (AFAIK)
they are non-existent on any modern computing platform and thus
impossible for us to test. (Also, the TurboJPEG API would break without
unsigned chars.)
Furthermore, the unified CMake-based build system introduced in 2.0
always defines HAVE_UNSIGNED_CHAR, so retaining other code paths is
pointless. Eliminating support for compilers without unsigned char
eliminates the need for the GETJSAMPLE() macro, which improves the
readability of many parts of the code as well as improving the
performance of writing Targa and Windows BMP files.
Fixes #317
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9c78a04d
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2018-07-20T17:21:36
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cjpeg: Fix OOB read caused by malformed 8-bit BMP
... in which one or more of the color indices is out of range for the
number of palette entries.
Fix partly borrowed from jpeg-9c. This commit also adopts Guido's
JERR_PPM_OUTOFRANGE enum value in lieu of our project-specific
JERR_PPM_TOOLARGE enum value.
Fixes #258
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43e84cff
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2018-06-12T20:27:00
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tjLoadImage(): Fix FPE triggered by malformed BMP
In rdbmp.c, it is necessary to guard against 32-bit overflow/wraparound
when allocating the row buffer, because since BMP files have 32-bit
width and height fields, the value of biWidth can be up to 4294967295.
Specifically, if biWidth is 1073741824 and cinfo->input_components = 4,
then the samplesperrow argument in alloc_sarray() would wrap around to
0, and a division by zero error would occur at line 458 in jmemmgr.c.
If biWidth is set to a higher value, then samplesperrow would wrap
around to a small number, which would likely cause a buffer overflow
(this has not been tested or verified.)
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19c791cd
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2018-03-08T10:55:20
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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.
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e817c077
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2017-11-19T08:43:07
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tjLoadImage(): return TJPF_GRAY for grayscale BMPs
... if *pixelFormat=TJPF_UNKNOWN is passed to the function.
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479fa1d8
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2017-11-18T11:33:05
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tjLoadImage(): Don't convert RGB to grayscale
Loading RGB image files into a grayscale buffer isn't a particularly
useful feature, given that libjpeg-turbo can perform this conversion
much more optimally (with SIMD acceleration on some platforms) during
the compression process. Also, the RGB2GRAY() macro was not producing
deterministic cross-platform results because of variations in the
round-off behavior of various floating point implementations, so
`tjunittest -bmp` was failing in i386 builds.
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aa745905
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2017-11-16T18:09:07
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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.
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bd49803f
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2016-02-19T08:53:33
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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.
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7e3acc0e
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2015-10-10T10:25:46
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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.
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a3ef34c6
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2015-08-13T11:09:05
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Fix cjpeg segfault when Windows BMP width/height<0
rdbmp.c used the ambiguous INT32 datatype, which is sometimes typedef'ed
to long. Windows bitmap headers use 32-bit signed integers for the
width and height, because height can sometimes be negative (this
indicates a top-down bitmap.) If biWidth or biHeight was negative and
INT32 was a 64-bit long, then biWidth and biHeight were read as a
positive integer > INT32_MAX, which failed the test in line 385:
if (biWidth <= 0 || biHeight <= 0)
ERREXIT(cinfo, JERR_BMP_EMPTY);
This commit refactors rdbmp.c so that it uses the datatypes specified by
Microsoft for the Windows BMP header.
This closes #9 and also provides a better solution for mozilla/mozjpeg#153.
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8fb37b81
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2015-08-13T11:09:05
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|
Fix cjpeg segfault when Windows BMP width/height<0
rdbmp.c used the ambiguous INT32 datatype, which is sometimes typedef'ed
to long. Windows bitmap headers use 32-bit signed integers for the
width and height, because height can sometimes be negative (this
indicates a top-down bitmap.) If biWidth or biHeight was negative and
INT32 was a 64-bit long, then biWidth and biHeight were read as a
positive integer > INT32_MAX, which failed the test in line 385:
if (biWidth <= 0 || biHeight <= 0)
ERREXIT(cinfo, JERR_BMP_EMPTY);
This commit refactors rdbmp.c so that it uses the datatypes specified by
Microsoft for the Windows BMP header.
This closes #9 and also provides a better solution for mozilla/mozjpeg#153.
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a2e6a9dd
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2006-02-04T00:00:00
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IJG R6b with x86SIMD V1.02
Independent JPEG Group's JPEG software release 6b
with x86 SIMD extension for IJG JPEG library version 1.02
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489583f5
|
1996-02-07T00:00:00
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The Independent JPEG Group's JPEG software v6a
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bc79e068
|
1995-08-02T00:00:00
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The Independent JPEG Group's JPEG software v6
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9ba2f5ed
|
1994-12-07T00:00:00
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The Independent JPEG Group's JPEG software v5a
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36a4cccc
|
1994-09-24T00:00:00
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|
The Independent JPEG Group's JPEG software v5
|
|
f18f81b7
|
2010-02-28T00:00:00
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|
The Independent JPEG Group's JPEG software v8a
|
|
989630f7
|
2010-01-10T00:00:00
|
|
The Independent JPEG Group's JPEG software v8
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5de454b2
|
2014-05-18T19:04:03
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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
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b7753510
|
2014-05-11T09:36:25
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|
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
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e5eaf374
|
2014-05-09T18:00:32
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|
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
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61976bd8
|
2014-04-20T19:13:10
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We use __CHAR_UNSIGNED__ (automatically defined by the AC_C_CHAR_UNSIGNED macro) rather than CHAR_IS_UNSIGNED (defined by custom autoconf code in libjpeg that we didn't port over), although I doubt it matters on any of the platforms we support.
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@1264 632fc199-4ca6-4c93-a231-07263d6284db
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a6ef282a
|
2013-09-28T03:23:49
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Some of the IJG headers say "Modified by", so clarify that our "Modifications" are not referring to these.
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@1053 632fc199-4ca6-4c93-a231-07263d6284db
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cf763c0c
|
2013-01-01T09:51:37
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|
Further changes to the copyright/attribution notices to make it clear that our modified files are not part of the IJG's software.
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.2.x@876 632fc199-4ca6-4c93-a231-07263d6284db
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83c8f14f
|
2011-04-25T22:53:44
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|
Eliminate excessive I/O overhead when reading BMP files in cjpeg
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.0.x@595 632fc199-4ca6-4c93-a231-07263d6284db
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049aef51
|
2011-04-25T22:41:14
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|
Eliminate excessive I/O overhead when reading BMP files in cjpeg
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.1.x@592 632fc199-4ca6-4c93-a231-07263d6284db
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c8753072
|
2006-05-25T05:01:55
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Migrating to new directory structure adopted from the RealVNC's source tree. More changes will follow.
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1 632fc199-4ca6-4c93-a231-07263d6284db
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