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diff --git a/media/libjpeg/ChangeLog.md b/media/libjpeg/ChangeLog.md new file mode 100644 index 0000000000..e6700c3c27 --- /dev/null +++ b/media/libjpeg/ChangeLog.md @@ -0,0 +1,1839 @@ +2.1.3 +===== + +### Significant changes relative to 2.1.2 + +1. Fixed a regression introduced by 2.0 beta1[7] whereby cjpeg compressed PGM +input files into full-color JPEG images unless the `-grayscale` option was +used. + +2. cjpeg now automatically compresses GIF and 8-bit BMP input files into +grayscale JPEG images if the input files contain only shades of gray. + +3. The build system now enables the intrinsics implementation of the AArch64 +(Arm 64-bit) Neon SIMD extensions by default when using GCC 12 or later. + +4. Fixed a segfault that occurred while decompressing a 4:2:0 JPEG image using +the merged (non-fancy) upsampling algorithms (that is, with +`cinfo.do_fancy_upsampling` set to `FALSE`) along with `jpeg_crop_scanline()`. +Specifically, the segfault occurred if the number of bytes remaining in the +output buffer was less than the number of bytes required to represent one +uncropped scanline of the output image. For that reason, the issue could only +be reproduced using the libjpeg API, not using djpeg. + + +2.1.2 +===== + +### Significant changes relative to 2.1.1 + +1. Fixed a regression introduced by 2.1 beta1[13] that caused the remaining +GAS implementations of AArch64 (Arm 64-bit) Neon SIMD functions (which are used +by default with GCC for performance reasons) to be placed in the `.rodata` +section rather than in the `.text` section. This caused the GNU linker to +automatically place the `.rodata` section in an executable segment, which +prevented libjpeg-turbo from working properly with other linkers and also +represented a potential security risk. + +2. Fixed an issue whereby the `tjTransform()` function incorrectly computed the +MCU block size for 4:4:4 JPEG images with non-unary sampling factors and thus +unduly rejected some cropping regions, even though those regions aligned with +8x8 MCU block boundaries. + +3. Fixed a regression introduced by 2.1 beta1[13] that caused the build system +to enable the Arm Neon SIMD extensions when targetting Armv6 and other legacy +architectures that do not support Neon instructions. + +4. libjpeg-turbo now performs run-time detection of AltiVec instructions on +FreeBSD/PowerPC systems if AltiVec instructions are not enabled at compile +time. This allows both AltiVec-equipped and non-AltiVec-equipped CPUs to be +supported using the same build of libjpeg-turbo. + +5. cjpeg now accepts a `-strict` argument similar to that of djpeg and +jpegtran, which causes the compressor to abort if an LZW-compressed GIF input +image contains incomplete or corrupt image data. + + +2.1.1 +===== + +### Significant changes relative to 2.1.0 + +1. Fixed a regression introduced in 2.1.0 that caused build failures with +non-GCC-compatible compilers for Un*x/Arm platforms. + +2. Fixed a regression introduced by 2.1 beta1[13] that prevented the Arm 32-bit +(AArch32) Neon SIMD extensions from building unless the C compiler flags +included `-mfloat-abi=softfp` or `-mfloat-abi=hard`. + +3. Fixed an issue in the AArch32 Neon SIMD Huffman encoder whereby reliance on +undefined C compiler behavior led to crashes ("SIGBUS: illegal alignment") on +Android systems when running AArch32/Thumb builds of libjpeg-turbo built with +recent versions of Clang. + +4. Added a command-line argument (`-copy icc`) to jpegtran that causes it to +copy only the ICC profile markers from the source file and discard any other +metadata. + +5. libjpeg-turbo should now build and run on CHERI-enabled architectures, which +use capability pointers that are larger than the size of `size_t`. + +6. Fixed a regression (CVE-2021-37972) introduced by 2.1 beta1[5] that caused a +segfault in the 64-bit SSE2 Huffman encoder when attempting to losslessly +transform a specially-crafted malformed JPEG image. + + +2.1.0 +===== + +### Significant changes relative to 2.1 beta1 + +1. Fixed a regression introduced by 2.1 beta1[6(b)] whereby attempting to +decompress certain progressive JPEG images with one or more component planes of +width 8 or less caused a buffer overrun. + +2. Fixed a regression introduced by 2.1 beta1[6(b)] whereby attempting to +decompress a specially-crafted malformed progressive JPEG image caused the +block smoothing algorithm to read from uninitialized memory. + +3. Fixed an issue in the Arm Neon SIMD Huffman encoders that caused the +encoders to generate incorrect results when using the Clang compiler with +Visual Studio. + +4. Fixed a floating point exception (CVE-2021-20205) that occurred when +attempting to compress a specially-crafted malformed GIF image with a specified +image width of 0 using cjpeg. + +5. Fixed a regression introduced by 2.0 beta1[15] whereby attempting to +generate a progressive JPEG image on an SSE2-capable CPU using a scan script +containing one or more scans with lengths divisible by 32 and non-zero +successive approximation low bit positions would, under certain circumstances, +result in an error ("Missing Huffman code table entry") and an invalid JPEG +image. + +6. Introduced a new flag (`TJFLAG_LIMITSCANS` in the TurboJPEG C API and +`TJ.FLAG_LIMIT_SCANS` in the TurboJPEG Java API) and a corresponding TJBench +command-line argument (`-limitscans`) that causes the TurboJPEG decompression +and transform functions/operations to return/throw an error if a progressive +JPEG image contains an unreasonably large number of scans. This allows +applications that use the TurboJPEG API to guard against an exploit of the +progressive JPEG format described in the report +["Two Issues with the JPEG Standard"](https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf). + +7. The PPM reader now throws an error, rather than segfaulting (due to a buffer +overrun) or generating incorrect pixels, if an application attempts to use the +`tjLoadImage()` function to load a 16-bit binary PPM file (a binary PPM file +with a maximum value greater than 255) into a grayscale image buffer or to load +a 16-bit binary PGM file into an RGB image buffer. + +8. Fixed an issue in the PPM reader that caused incorrect pixels to be +generated when using the `tjLoadImage()` function to load a 16-bit binary PPM +file into an extended RGB image buffer. + +9. Fixed an issue whereby, if a JPEG buffer was automatically re-allocated by +one of the TurboJPEG compression or transform functions and an error +subsequently occurred during compression or transformation, the JPEG buffer +pointer passed by the application was not updated when the function returned. + + +2.0.90 (2.1 beta1) +================== + +### Significant changes relative to 2.0.6: + +1. The build system, x86-64 SIMD extensions, and accelerated Huffman codec now +support the x32 ABI on Linux, which allows for using x86-64 instructions with +32-bit pointers. The x32 ABI is generally enabled by adding `-mx32` to the +compiler flags. + + Caveats: + - CMake 3.9.0 or later is required in order for the build system to +automatically detect an x32 build. + - Java does not support the x32 ABI, and thus the TurboJPEG Java API will +automatically be disabled with x32 builds. + +2. Added Loongson MMI SIMD implementations of the RGB-to-grayscale, 4:2:2 fancy +chroma upsampling, 4:2:2 and 4:2:0 merged chroma upsampling/color conversion, +and fast integer DCT/IDCT algorithms. Relative to libjpeg-turbo 2.0.x, this +speeds up: + + - the compression of RGB source images into grayscale JPEG images by +approximately 20% + - the decompression of 4:2:2 JPEG images by approximately 40-60% when +using fancy upsampling + - the decompression of 4:2:2 and 4:2:0 JPEG images by approximately +15-20% when using merged upsampling + - the compression of RGB source images by approximately 30-45% when using +the fast integer DCT + - the decompression of JPEG images into RGB destination images by +approximately 2x when using the fast integer IDCT + + The overall decompression speedup for RGB images is now approximately +2.3-3.7x (compared to 2-3.5x with libjpeg-turbo 2.0.x.) + +3. 32-bit (Armv7 or Armv7s) iOS builds of libjpeg-turbo are no longer +supported, and the libjpeg-turbo build system can no longer be used to package +such builds. 32-bit iOS apps cannot run in iOS 11 and later, and the App Store +no longer allows them. + +4. 32-bit (i386) OS X/macOS builds of libjpeg-turbo are no longer supported, +and the libjpeg-turbo build system can no longer be used to package such +builds. 32-bit Mac applications cannot run in macOS 10.15 "Catalina" and +later, and the App Store no longer allows them. + +5. The SSE2 (x86 SIMD) and C Huffman encoding algorithms have been +significantly optimized, resulting in a measured average overall compression +speedup of 12-28% for 64-bit code and 22-52% for 32-bit code on various Intel +and AMD CPUs, as well as a measured average overall compression speedup of +0-23% on platforms that do not have a SIMD-accelerated Huffman encoding +implementation. + +6. The block smoothing algorithm that is applied by default when decompressing +progressive Huffman-encoded JPEG images has been improved in the following +ways: + + - The algorithm is now more fault-tolerant. Previously, if a particular +scan was incomplete, then the smoothing parameters for the incomplete scan +would be applied to the entire output image, including the parts of the image +that were generated by the prior (complete) scan. Visually, this had the +effect of removing block smoothing from lower-frequency scans if they were +followed by an incomplete higher-frequency scan. libjpeg-turbo now applies +block smoothing parameters to each iMCU row based on which scan generated the +pixels in that row, rather than always using the block smoothing parameters for +the most recent scan. + - When applying block smoothing to DC scans, a Gaussian-like kernel with a +5x5 window is used to reduce the "blocky" appearance. + +7. Added SIMD acceleration for progressive Huffman encoding on Arm platforms. +This speeds up the compression of full-color progressive JPEGs by about 30-40% +on average (relative to libjpeg-turbo 2.0.x) when using modern Arm CPUs. + +8. Added configure-time and run-time auto-detection of Loongson MMI SIMD +instructions, so that the Loongson MMI SIMD extensions can be included in any +MIPS64 libjpeg-turbo build. + +9. Added fault tolerance features to djpeg and jpegtran, mainly to demonstrate +methods by which applications can guard against the exploits of the JPEG format +described in the report +["Two Issues with the JPEG Standard"](https://libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf). + + - Both programs now accept a `-maxscans` argument, which can be used to +limit the number of allowable scans in the input file. + - Both programs now accept a `-strict` argument, which can be used to +treat all warnings as fatal. + +10. CMake package config files are now included for both the libjpeg and +TurboJPEG API libraries. This facilitates using libjpeg-turbo with CMake's +`find_package()` function. For example: + + find_package(libjpeg-turbo CONFIG REQUIRED) + + add_executable(libjpeg_program libjpeg_program.c) + target_link_libraries(libjpeg_program PUBLIC libjpeg-turbo::jpeg) + + add_executable(libjpeg_program_static libjpeg_program.c) + target_link_libraries(libjpeg_program_static PUBLIC + libjpeg-turbo::jpeg-static) + + add_executable(turbojpeg_program turbojpeg_program.c) + target_link_libraries(turbojpeg_program PUBLIC + libjpeg-turbo::turbojpeg) + + add_executable(turbojpeg_program_static turbojpeg_program.c) + target_link_libraries(turbojpeg_program_static PUBLIC + libjpeg-turbo::turbojpeg-static) + +11. Since the Unisys LZW patent has long expired, cjpeg and djpeg can now +read/write both LZW-compressed and uncompressed GIF files (feature ported from +jpeg-6a and jpeg-9d.) + +12. jpegtran now includes the `-wipe` and `-drop` options from jpeg-9a and +jpeg-9d, as well as the ability to expand the image size using the `-crop` +option. Refer to jpegtran.1 or usage.txt for more details. + +13. Added a complete intrinsics implementation of the Arm Neon SIMD extensions, +thus providing SIMD acceleration on Arm platforms for all of the algorithms +that are SIMD-accelerated on x86 platforms. This new implementation is +significantly faster in some cases than the old GAS implementation-- +depending on the algorithms used, the type of CPU core, and the compiler. GCC, +as of this writing, does not provide a full or optimal set of Neon intrinsics, +so for performance reasons, the default when building libjpeg-turbo with GCC is +to continue using the GAS implementation of the following algorithms: + + - 32-bit RGB-to-YCbCr color conversion + - 32-bit fast and accurate inverse DCT + - 64-bit RGB-to-YCbCr and YCbCr-to-RGB color conversion + - 64-bit accurate forward and inverse DCT + - 64-bit Huffman encoding + + A new CMake variable (`NEON_INTRINSICS`) can be used to override this +default. + + Since the new intrinsics implementation includes SIMD acceleration +for merged upsampling/color conversion, 1.5.1[5] is no longer necessary and has +been reverted. + +14. The Arm Neon SIMD extensions can now be built using Visual Studio. + +15. The build system can now be used to generate a universal x86-64 + Armv8 +libjpeg-turbo SDK package for both iOS and macOS. + + +2.0.6 +===== + +### Significant changes relative to 2.0.5: + +1. Fixed "using JNI after critical get" errors that occurred on Android +platforms when using any of the YUV encoding/compression/decompression/decoding +methods in the TurboJPEG Java API. + +2. Fixed or worked around multiple issues with `jpeg_skip_scanlines()`: + + - Fixed segfaults or "Corrupt JPEG data: premature end of data segment" +errors in `jpeg_skip_scanlines()` that occurred when decompressing 4:2:2 or +4:2:0 JPEG images using merged (non-fancy) upsampling/color conversion (that +is, when setting `cinfo.do_fancy_upsampling` to `FALSE`.) 2.0.0[6] was a +similar fix, but it did not cover all cases. + - `jpeg_skip_scanlines()` now throws an error if two-pass color +quantization is enabled. Two-pass color quantization never worked properly +with `jpeg_skip_scanlines()`, and the issues could not readily be fixed. + - Fixed an issue whereby `jpeg_skip_scanlines()` always returned 0 when +skipping past the end of an image. + +3. The Arm 64-bit (Armv8) Neon SIMD extensions can now be built using MinGW +toolchains targetting Arm64 (AArch64) Windows binaries. + +4. Fixed unexpected visual artifacts that occurred when using +`jpeg_crop_scanline()` and interblock smoothing while decompressing only the DC +scan of a progressive JPEG image. + +5. Fixed an issue whereby libjpeg-turbo would not build if 12-bit-per-component +JPEG support (`WITH_12BIT`) was enabled along with libjpeg v7 or libjpeg v8 +API/ABI emulation (`WITH_JPEG7` or `WITH_JPEG8`.) + + +2.0.5 +===== + +### Significant changes relative to 2.0.4: + +1. Worked around issues in the MIPS DSPr2 SIMD extensions that caused failures +in the libjpeg-turbo regression tests. Specifically, the +`jsimd_h2v1_downsample_dspr2()` and `jsimd_h2v2_downsample_dspr2()` functions +in the MIPS DSPr2 SIMD extensions are now disabled until/unless they can be +fixed, and other functions that are incompatible with big endian MIPS CPUs are +disabled when building libjpeg-turbo for such CPUs. + +2. Fixed an oversight in the `TJCompressor.compress(int)` method in the +TurboJPEG Java API that caused an error ("java.lang.IllegalStateException: No +source image is associated with this instance") when attempting to use that +method to compress a YUV image. + +3. Fixed an issue (CVE-2020-13790) in the PPM reader that caused a buffer +overrun in cjpeg, TJBench, or the `tjLoadImage()` function if one of the values +in a binary PPM/PGM input file exceeded the maximum value defined in the file's +header and that maximum value was less than 255. libjpeg-turbo 1.5.0 already +included a similar fix for binary PPM/PGM files with maximum values greater +than 255. + +4. The TurboJPEG API library's global error handler, which is used in functions +such as `tjBufSize()` and `tjLoadImage()` that do not require a TurboJPEG +instance handle, is now thread-safe on platforms that support thread-local +storage. + + +2.0.4 +===== + +### Significant changes relative to 2.0.3: + +1. Fixed a regression in the Windows packaging system (introduced by +2.0 beta1[2]) whereby, if both the 64-bit libjpeg-turbo SDK for GCC and the +64-bit libjpeg-turbo SDK for Visual C++ were installed on the same system, only +one of them could be uninstalled. + +2. Fixed a signed integer overflow and subsequent segfault that occurred when +attempting to decompress images with more than 715827882 pixels using the +64-bit C version of TJBench. + +3. Fixed out-of-bounds write in `tjDecompressToYUV2()` and +`tjDecompressToYUVPlanes()` (sometimes manifesting as a double free) that +occurred when attempting to decompress grayscale JPEG images that were +compressed with a sampling factor other than 1 (for instance, with +`cjpeg -grayscale -sample 2x2`). + +4. Fixed a regression introduced by 2.0.2[5] that caused the TurboJPEG API to +incorrectly identify some JPEG images with unusual sampling factors as 4:4:4 +JPEG images. This was known to cause a buffer overflow when attempting to +decompress some such images using `tjDecompressToYUV2()` or +`tjDecompressToYUVPlanes()`. + +5. Fixed an issue (CVE-2020-17541), detected by ASan, whereby attempting to +losslessly transform a specially-crafted malformed JPEG image containing an +extremely-high-frequency coefficient block (junk image data that could never be +generated by a legitimate JPEG compressor) could cause the Huffman encoder's +local buffer to be overrun. (Refer to 1.4.0[9] and 1.4beta1[15].) Given that +the buffer overrun was fully contained within the stack and did not cause a +segfault or other user-visible errant behavior, and given that the lossless +transformer (unlike the decompressor) is not generally exposed to arbitrary +data exploits, this issue did not likely pose a security risk. + +6. The Arm 64-bit (Armv8) Neon SIMD assembly code now stores constants in a +separate read-only data section rather than in the text section, to support +execute-only memory layouts. + + +2.0.3 +===== + +### Significant changes relative to 2.0.2: + +1. Fixed "using JNI after critical get" errors that occurred on Android +platforms when passing invalid arguments to certain methods in the TurboJPEG +Java API. + +2. Fixed a regression in the SIMD feature detection code, introduced by +the AVX2 SIMD extensions (2.0 beta1[1]), that was known to cause an illegal +instruction exception, in rare cases, on CPUs that lack support for CPUID leaf +07H (or on which the maximum CPUID leaf has been limited by way of a BIOS +setting.) + +3. The 4:4:0 (h1v2) fancy (smooth) chroma upsampling algorithm in the +decompressor now uses a similar bias pattern to that of the 4:2:2 (h2v1) fancy +chroma upsampling algorithm, rounding up or down the upsampled result for +alternate pixels rather than always rounding down. This ensures that, +regardless of whether a 4:2:2 JPEG image is rotated or transposed prior to +decompression (in the frequency domain) or after decompression (in the spatial +domain), the final image will be similar. + +4. Fixed an integer overflow and subsequent segfault that occurred when +attempting to compress or decompress images with more than 1 billion pixels +using the TurboJPEG API. + +5. Fixed a regression introduced by 2.0 beta1[15] whereby attempting to +generate a progressive JPEG image on an SSE2-capable CPU using a scan script +containing one or more scans with lengths divisible by 16 would result in an +error ("Missing Huffman code table entry") and an invalid JPEG image. + +6. Fixed an issue whereby `tjDecodeYUV()` and `tjDecodeYUVPlanes()` would throw +an error ("Invalid progressive parameters") or a warning ("Inconsistent +progression sequence") if passed a TurboJPEG instance that was previously used +to decompress a progressive JPEG image. + + +2.0.2 +===== + +### Significant changes relative to 2.0.1: + +1. Fixed a regression introduced by 2.0.1[5] that prevented a runtime search +path (rpath) from being embedded in the libjpeg-turbo shared libraries and +executables for macOS and iOS. This caused a fatal error of the form +"dyld: Library not loaded" when attempting to use one of the executables, +unless `DYLD_LIBRARY_PATH` was explicitly set to the location of the +libjpeg-turbo shared libraries. + +2. Fixed an integer overflow and subsequent segfault (CVE-2018-20330) that +occurred when attempting to load a BMP file with more than 1 billion pixels +using the `tjLoadImage()` function. + +3. Fixed a buffer overrun (CVE-2018-19664) that occurred when attempting to +decompress a specially-crafted malformed JPEG image to a 256-color BMP using +djpeg. + +4. Fixed a floating point exception that occurred when attempting to +decompress a specially-crafted malformed JPEG image with a specified image +width or height of 0 using the C version of TJBench. + +5. The TurboJPEG API will now decompress 4:4:4 JPEG images with 2x1, 1x2, 3x1, +or 1x3 luminance and chrominance sampling factors. This is a non-standard way +of specifying 1x subsampling (normally 4:4:4 JPEGs have 1x1 luminance and +chrominance sampling factors), but the JPEG format and the libjpeg API both +allow it. + +6. Fixed a regression introduced by 2.0 beta1[7] that caused djpeg to generate +incorrect PPM images when used with the `-colors` option. + +7. Fixed an issue whereby a static build of libjpeg-turbo (a build in which +`ENABLE_SHARED` is `0`) could not be installed using the Visual Studio IDE. + +8. Fixed a severe performance issue in the Loongson MMI SIMD extensions that +occurred when compressing RGB images whose image rows were not 64-bit-aligned. + + +2.0.1 +===== + +### Significant changes relative to 2.0.0: + +1. Fixed a regression introduced with the new CMake-based Un*x build system, +whereby jconfig.h could cause compiler warnings of the form +`"HAVE_*_H" redefined` if it was included by downstream Autotools-based +projects that used `AC_CHECK_HEADERS()` to check for the existence of locale.h, +stddef.h, or stdlib.h. + +2. The `jsimd_quantize_float_dspr2()` and `jsimd_convsamp_float_dspr2()` +functions in the MIPS DSPr2 SIMD extensions are now disabled at compile time +if the soft float ABI is enabled. Those functions use instructions that are +incompatible with the soft float ABI. + +3. Fixed a regression in the SIMD feature detection code, introduced by +the AVX2 SIMD extensions (2.0 beta1[1]), that caused libjpeg-turbo to crash on +Windows 7 if Service Pack 1 was not installed. + +4. Fixed out-of-bounds read in cjpeg that occurred when attempting to compress +a specially-crafted malformed color-index (8-bit-per-sample) Targa file in +which some of the samples (color indices) exceeded the bounds of the Targa +file's color table. + +5. Fixed an issue whereby installing a fully static build of libjpeg-turbo +(a build in which `CFLAGS` contains `-static` and `ENABLE_SHARED` is `0`) would +fail with "No valid ELF RPATH or RUNPATH entry exists in the file." + + +2.0.0 +===== + +### Significant changes relative to 2.0 beta1: + +1. The TurboJPEG API can now decompress CMYK JPEG images that have subsampled M +and Y components (not to be confused with YCCK JPEG images, in which the C/M/Y +components have been transformed into luma and chroma.) Previously, an error +was generated ("Could not determine subsampling type for JPEG image") when such +an image was passed to `tjDecompressHeader3()`, `tjTransform()`, +`tjDecompressToYUVPlanes()`, `tjDecompressToYUV2()`, or the equivalent Java +methods. + +2. Fixed an issue (CVE-2018-11813) whereby a specially-crafted malformed input +file (specifically, a file with a valid Targa header but incomplete pixel data) +would cause cjpeg to generate a JPEG file that was potentially thousands of +times larger than the input file. The Targa reader in cjpeg was not properly +detecting that the end of the input file had been reached prematurely, so after +all valid pixels had been read from the input, the reader injected dummy pixels +with values of 255 into the JPEG compressor until the number of pixels +specified in the Targa header had been compressed. The Targa reader in cjpeg +now behaves like the PPM reader and aborts compression if the end of the input +file is reached prematurely. Because this issue only affected cjpeg and not +the underlying library, and because it did not involve any out-of-bounds reads +or other exploitable behaviors, it was not believed to represent a security +threat. + +3. Fixed an issue whereby the `tjLoadImage()` and `tjSaveImage()` functions +would produce a "Bogus message code" error message if the underlying bitmap and +PPM readers/writers threw an error that was specific to the readers/writers +(as opposed to a general libjpeg API error.) + +4. Fixed an issue (CVE-2018-1152) whereby a specially-crafted malformed BMP +file, one in which the header specified an image width of 1073741824 pixels, +would trigger a floating point exception (division by zero) in the +`tjLoadImage()` function when attempting to load the BMP file into a +4-component image buffer. + +5. Fixed an issue whereby certain combinations of calls to +`jpeg_skip_scanlines()` and `jpeg_read_scanlines()` could trigger an infinite +loop when decompressing progressive JPEG images that use vertical chroma +subsampling (for instance, 4:2:0 or 4:4:0.) + +6. Fixed a segfault in `jpeg_skip_scanlines()` that occurred when decompressing +a 4:2:2 or 4:2:0 JPEG image using the merged (non-fancy) upsampling algorithms +(that is, when setting `cinfo.do_fancy_upsampling` to `FALSE`.) + +7. The new CMake-based build system will now disable the MIPS DSPr2 SIMD +extensions if it detects that the compiler does not support DSPr2 instructions. + +8. Fixed out-of-bounds read in cjpeg (CVE-2018-14498) that occurred when +attempting to compress a specially-crafted malformed color-index +(8-bit-per-sample) BMP file in which some of the samples (color indices) +exceeded the bounds of the BMP file's color table. + +9. Fixed a signed integer overflow in the progressive Huffman decoder, detected +by the Clang and GCC undefined behavior sanitizers, that could be triggered by +attempting to decompress a specially-crafted malformed JPEG image. This issue +did not pose a security threat, but removing the warning made it easier to +detect actual security issues, should they arise in the future. + + +1.5.90 (2.0 beta1) +================== + +### Significant changes relative to 1.5.3: + +1. Added AVX2 SIMD implementations of the colorspace conversion, chroma +downsampling and upsampling, integer quantization and sample conversion, and +accurate integer DCT/IDCT algorithms. When using the accurate integer DCT/IDCT +algorithms on AVX2-equipped CPUs, the compression of RGB images is +approximately 13-36% (avg. 22%) faster (relative to libjpeg-turbo 1.5.x) with +64-bit code and 11-21% (avg. 17%) faster with 32-bit code, and the +decompression of RGB images is approximately 9-35% (avg. 17%) faster with +64-bit code and 7-17% (avg. 12%) faster with 32-bit code. (As tested on a +3 GHz Intel Core i7. Actual mileage may vary.) + +2. Overhauled the build system to use CMake on all platforms, and removed the +autotools-based build system. This decision resulted from extensive +discussions within the libjpeg-turbo community. libjpeg-turbo traditionally +used CMake only for Windows builds, but there was an increasing amount of +demand to extend CMake support to other platforms. However, because of the +unique nature of our code base (the need to support different assemblers on +each platform, the need for Java support, etc.), providing dual build systems +as other OSS imaging libraries do (including libpng and libtiff) would have +created a maintenance burden. The use of CMake greatly simplifies some aspects +of our build system, owing to CMake's built-in support for various assemblers, +Java, and unit testing, as well as generally fewer quirks that have to be +worked around in order to implement our packaging system. Eliminating +autotools puts our project slightly at odds with the traditional practices of +the OSS community, since most "system libraries" tend to be built with +autotools, but it is believed that the benefits of this move outweigh the +risks. In addition to providing a unified build environment, switching to +CMake allows for the use of various build tools and IDEs that aren't supported +under autotools, including XCode, Ninja, and Eclipse. It also eliminates the +need to install autotools via MacPorts/Homebrew on OS X and allows +libjpeg-turbo to be configured without the use of a terminal/command prompt. +Extensive testing was conducted to ensure that all features provided by the +autotools-based build system are provided by the new build system. + +3. The libjpeg API in this version of libjpeg-turbo now includes two additional +functions, `jpeg_read_icc_profile()` and `jpeg_write_icc_profile()`, that can +be used to extract ICC profile data from a JPEG file while decompressing or to +embed ICC profile data in a JPEG file while compressing or transforming. This +eliminates the need for downstream projects, such as color management libraries +and browsers, to include their own glueware for accomplishing this. + +4. Improved error handling in the TurboJPEG API library: + + - Introduced a new function (`tjGetErrorStr2()`) in the TurboJPEG C API +that allows compression/decompression/transform error messages to be retrieved +in a thread-safe manner. Retrieving error messages from global functions, such +as `tjInitCompress()` or `tjBufSize()`, is still thread-unsafe, but since those +functions will only throw errors if passed an invalid argument or if a memory +allocation failure occurs, thread safety is not as much of a concern. + - Introduced a new function (`tjGetErrorCode()`) in the TurboJPEG C API +and a new method (`TJException.getErrorCode()`) in the TurboJPEG Java API that +can be used to determine the severity of the last +compression/decompression/transform error. This allows applications to +choose whether to ignore warnings (non-fatal errors) from the underlying +libjpeg API or to treat them as fatal. + - Introduced a new flag (`TJFLAG_STOPONWARNING` in the TurboJPEG C API and +`TJ.FLAG_STOPONWARNING` in the TurboJPEG Java API) that causes the library to +immediately halt a compression/decompression/transform operation if it +encounters a warning from the underlying libjpeg API (the default behavior is +to allow the operation to complete unless a fatal error is encountered.) + +5. Introduced a new flag in the TurboJPEG C and Java APIs (`TJFLAG_PROGRESSIVE` +and `TJ.FLAG_PROGRESSIVE`, respectively) that causes the library to use +progressive entropy coding in JPEG images generated by compression and +transform operations. Additionally, a new transform option +(`TJXOPT_PROGRESSIVE` in the C API and `TJTransform.OPT_PROGRESSIVE` in the +Java API) has been introduced, allowing progressive entropy coding to be +enabled for selected transforms in a multi-transform operation. + +6. Introduced a new transform option in the TurboJPEG API (`TJXOPT_COPYNONE` in +the C API and `TJTransform.OPT_COPYNONE` in the Java API) that allows the +copying of markers (including EXIF and ICC profile data) to be disabled for a +particular transform. + +7. Added two functions to the TurboJPEG C API (`tjLoadImage()` and +`tjSaveImage()`) that can be used to load/save a BMP or PPM/PGM image to/from a +memory buffer with a specified pixel format and layout. These functions +replace the project-private (and slow) bmp API, which was previously used by +TJBench, and they also provide a convenient way for first-time users of +libjpeg-turbo to quickly develop a complete JPEG compression/decompression +program. + +8. The TurboJPEG C API now includes a new convenience array (`tjAlphaOffset[]`) +that contains the alpha component index for each pixel format (or -1 if the +pixel format lacks an alpha component.) The TurboJPEG Java API now includes a +new method (`TJ.getAlphaOffset()`) that returns the same value. In addition, +the `tjRedOffset[]`, `tjGreenOffset[]`, and `tjBlueOffset[]` arrays-- and the +corresponding `TJ.getRedOffset()`, `TJ.getGreenOffset()`, and +`TJ.getBlueOffset()` methods-- now return -1 for `TJPF_GRAY`/`TJ.PF_GRAY` +rather than 0. This allows programs to easily determine whether a pixel format +has red, green, blue, and alpha components. + +9. Added a new example (tjexample.c) that demonstrates the basic usage of the +TurboJPEG C API. This example mirrors the functionality of TJExample.java. +Both files are now included in the libjpeg-turbo documentation. + +10. Fixed two signed integer overflows in the arithmetic decoder, detected by +the Clang undefined behavior sanitizer, that could be triggered by attempting +to decompress a specially-crafted malformed JPEG image. These issues did not +pose a security threat, but removing the warnings makes it easier to detect +actual security issues, should they arise in the future. + +11. Fixed a bug in the merged 4:2:0 upsampling/dithered RGB565 color conversion +algorithm that caused incorrect dithering in the output image. This algorithm +now produces bitwise-identical results to the unmerged algorithms. + +12. The SIMD function symbols for x86[-64]/ELF, MIPS/ELF, macOS/x86[-64] (if +libjpeg-turbo is built with Yasm), and iOS/Arm[64] builds are now private. +This prevents those symbols from being exposed in applications or shared +libraries that link statically with libjpeg-turbo. + +13. Added Loongson MMI SIMD implementations of the RGB-to-YCbCr and +YCbCr-to-RGB colorspace conversion, 4:2:0 chroma downsampling, 4:2:0 fancy +chroma upsampling, integer quantization, and accurate integer DCT/IDCT +algorithms. When using the accurate integer DCT/IDCT, this speeds up the +compression of RGB images by approximately 70-100% and the decompression of RGB +images by approximately 2-3.5x. + +14. Fixed a build error when building with older MinGW releases (regression +caused by 1.5.1[7].) + +15. Added SIMD acceleration for progressive Huffman encoding on SSE2-capable +x86 and x86-64 platforms. This speeds up the compression of full-color +progressive JPEGs by about 85-90% on average (relative to libjpeg-turbo 1.5.x) +when using modern Intel and AMD CPUs. + + +1.5.3 +===== + +### Significant changes relative to 1.5.2: + +1. Fixed a NullPointerException in the TurboJPEG Java wrapper that occurred +when using the YUVImage constructor that creates an instance backed by separate +image planes and allocates memory for the image planes. + +2. Fixed an issue whereby the Java version of TJUnitTest would fail when +testing BufferedImage encoding/decoding on big endian systems. + +3. Fixed a segfault in djpeg that would occur if an output format other than +PPM/PGM was selected along with the `-crop` option. The `-crop` option now +works with the GIF and Targa formats as well (unfortunately, it cannot be made +to work with the BMP and RLE formats due to the fact that those output engines +write scanlines in bottom-up order.) djpeg will now exit gracefully if an +output format other than PPM/PGM, GIF, or Targa is selected along with the +`-crop` option. + +4. Fixed an issue (CVE-2017-15232) whereby `jpeg_skip_scanlines()` would +segfault if color quantization was enabled. + +5. TJBench (both C and Java versions) will now display usage information if any +command-line argument is unrecognized. This prevents the program from silently +ignoring typos. + +6. Fixed an access violation in tjbench.exe (Windows) that occurred when the +program was used to decompress an existing JPEG image. + +7. Fixed an ArrayIndexOutOfBoundsException in the TJExample Java program that +occurred when attempting to decompress a JPEG image that had been compressed +with 4:1:1 chrominance subsampling. + +8. Fixed an issue whereby, when using `jpeg_skip_scanlines()` to skip to the +end of a single-scan (non-progressive) image, subsequent calls to +`jpeg_consume_input()` would return `JPEG_SUSPENDED` rather than +`JPEG_REACHED_EOI`. + +9. `jpeg_crop_scanline()` now works correctly when decompressing grayscale JPEG +images that were compressed with a sampling factor other than 1 (for instance, +with `cjpeg -grayscale -sample 2x2`). + + +1.5.2 +===== + +### Significant changes relative to 1.5.1: + +1. Fixed a regression introduced by 1.5.1[7] that prevented libjpeg-turbo from +building with Android NDK platforms prior to android-21 (5.0). + +2. Fixed a regression introduced by 1.5.1[1] that prevented the MIPS DSPR2 SIMD +code in libjpeg-turbo from building. + +3. Fixed a regression introduced by 1.5 beta1[11] that prevented the Java +version of TJBench from outputting any reference images (the `-nowrite` switch +was accidentally enabled by default.) + +4. libjpeg-turbo should now build and run with full AltiVec SIMD acceleration +on PowerPC-based AmigaOS 4 and OpenBSD systems. + +5. Fixed build and runtime errors on Windows that occurred when building +libjpeg-turbo with libjpeg v7 API/ABI emulation and the in-memory +source/destination managers. Due to an oversight, the `jpeg_skip_scanlines()` +and `jpeg_crop_scanline()` functions were not being included in jpeg7.dll when +libjpeg-turbo was built with `-DWITH_JPEG7=1` and `-DWITH_MEMSRCDST=1`. + +6. Fixed "Bogus virtual array access" error that occurred when using the +lossless crop feature in jpegtran or the TurboJPEG API, if libjpeg-turbo was +built with libjpeg v7 API/ABI emulation. This was apparently a long-standing +bug that has existed since the introduction of libjpeg v7/v8 API/ABI emulation +in libjpeg-turbo v1.1. + +7. The lossless transform features in jpegtran and the TurboJPEG API will now +always attempt to adjust the EXIF image width and height tags if the image size +changed as a result of the transform. This behavior has always existed when +using libjpeg v8 API/ABI emulation. It was supposed to be available with +libjpeg v7 API/ABI emulation as well but did not work properly due to a bug. +Furthermore, there was never any good reason not to enable it with libjpeg v6b +API/ABI emulation, since the behavior is entirely internal. Note that +`-copy all` must be passed to jpegtran in order to transfer the EXIF tags from +the source image to the destination image. + +8. Fixed several memory leaks in the TurboJPEG API library that could occur +if the library was built with certain compilers and optimization levels +(known to occur with GCC 4.x and clang with `-O1` and higher but not with +GCC 5.x or 6.x) and one of the underlying libjpeg API functions threw an error +after a TurboJPEG API function allocated a local buffer. + +9. The libjpeg-turbo memory manager will now honor the `max_memory_to_use` +structure member in jpeg\_memory\_mgr, which can be set to the maximum amount +of memory (in bytes) that libjpeg-turbo should use during decompression or +multi-pass (including progressive) compression. This limit can also be set +using the `JPEGMEM` environment variable or using the `-maxmemory` switch in +cjpeg/djpeg/jpegtran (refer to the respective man pages for more details.) +This has been a documented feature of libjpeg since v5, but the +`malloc()`/`free()` implementation of the memory manager (jmemnobs.c) never +implemented the feature. Restricting libjpeg-turbo's memory usage is useful +for two reasons: it allows testers to more easily work around the 2 GB limit +in libFuzzer, and it allows developers of security-sensitive applications to +more easily defend against one of the progressive JPEG exploits (LJT-01-004) +identified in +[this report](http://www.libjpeg-turbo.org/pmwiki/uploads/About/TwoIssueswiththeJPEGStandard.pdf). + +10. TJBench will now run each benchmark for 1 second prior to starting the +timer, in order to improve the consistency of the results. Furthermore, the +`-warmup` option is now used to specify the amount of warmup time rather than +the number of warmup iterations. + +11. Fixed an error (`short jump is out of range`) that occurred when assembling +the 32-bit x86 SIMD extensions with NASM versions prior to 2.04. This was a +regression introduced by 1.5 beta1[12]. + + +1.5.1 +===== + +### Significant changes relative to 1.5.0: + +1. Previously, the undocumented `JSIMD_FORCE*` environment variables could be +used to force-enable a particular SIMD instruction set if multiple instruction +sets were available on a particular platform. On x86 platforms, where CPU +feature detection is bulletproof and multiple SIMD instruction sets are +available, it makes sense for those environment variables to allow forcing the +use of an instruction set only if that instruction set is available. However, +since the ARM implementations of libjpeg-turbo can only use one SIMD +instruction set, and since their feature detection code is less bulletproof +(parsing /proc/cpuinfo), it makes sense for the `JSIMD_FORCENEON` environment +variable to bypass the feature detection code and really force the use of NEON +instructions. A new environment variable (`JSIMD_FORCEDSPR2`) was introduced +in the MIPS implementation for the same reasons, and the existing +`JSIMD_FORCENONE` environment variable was extended to that implementation. +These environment variables provide a workaround for those attempting to test +ARM and MIPS builds of libjpeg-turbo in QEMU, which passes through +/proc/cpuinfo from the host system. + +2. libjpeg-turbo previously assumed that AltiVec instructions were always +available on PowerPC platforms, which led to "illegal instruction" errors when +running on PowerPC chips that lack AltiVec support (such as the older 7xx/G3 +and newer e5500 series.) libjpeg-turbo now examines /proc/cpuinfo on +Linux/Android systems and enables AltiVec instructions only if the CPU supports +them. It also now provides two environment variables, `JSIMD_FORCEALTIVEC` and +`JSIMD_FORCENONE`, to force-enable and force-disable AltiVec instructions in +environments where /proc/cpuinfo is an unreliable means of CPU feature +detection (such as when running in QEMU.) On OS X, libjpeg-turbo continues to +assume that AltiVec support is always available, which means that libjpeg-turbo +cannot be used with G3 Macs unless you set the environment variable +`JSIMD_FORCENONE` to `1`. + +3. Fixed an issue whereby 64-bit ARM (AArch64) builds of libjpeg-turbo would +crash when built with recent releases of the Clang/LLVM compiler. This was +caused by an ABI conformance issue in some of libjpeg-turbo's 64-bit NEON SIMD +routines. Those routines were incorrectly using 64-bit instructions to +transfer a 32-bit JDIMENSION argument, whereas the ABI allows the upper +(unused) 32 bits of a 32-bit argument's register to be undefined. The new +Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit +structure members into a single 64-bit register, and this exposed the ABI +conformance issue. + +4. Fancy upsampling is now supported when decompressing JPEG images that use +4:4:0 (h1v2) chroma subsampling. These images are generated when losslessly +rotating or transposing JPEG images that use 4:2:2 (h2v1) chroma subsampling. +The h1v2 fancy upsampling algorithm is not currently SIMD-accelerated. + +5. If merged upsampling isn't SIMD-accelerated but YCbCr-to-RGB conversion is, +then libjpeg-turbo will now disable merged upsampling when decompressing YCbCr +JPEG images into RGB or extended RGB output images. This significantly speeds +up the decompression of 4:2:0 and 4:2:2 JPEGs on ARM platforms if fancy +upsampling is not used (for example, if the `-nosmooth` option to djpeg is +specified.) + +6. The TurboJPEG API will now decompress 4:2:2 and 4:4:0 JPEG images with +2x2 luminance sampling factors and 2x1 or 1x2 chrominance sampling factors. +This is a non-standard way of specifying 2x subsampling (normally 4:2:2 JPEGs +have 2x1 luminance and 1x1 chrominance sampling factors, and 4:4:0 JPEGs have +1x2 luminance and 1x1 chrominance sampling factors), but the JPEG format and +the libjpeg API both allow it. + +7. Fixed an unsigned integer overflow in the libjpeg memory manager, detected +by the Clang undefined behavior sanitizer, that could be triggered by +attempting to decompress a specially-crafted malformed JPEG image. This issue +affected only 32-bit code and did not pose a security threat, but removing the +warning makes it easier to detect actual security issues, should they arise in +the future. + +8. Fixed additional negative left shifts and other issues reported by the GCC +and Clang undefined behavior sanitizers when attempting to decompress +specially-crafted malformed JPEG images. None of these issues posed a security +threat, but removing the warnings makes it easier to detect actual security +issues, should they arise in the future. + +9. Fixed an out-of-bounds array reference, introduced by 1.4.90[2] (partial +image decompression) and detected by the Clang undefined behavior sanitizer, +that could be triggered by a specially-crafted malformed JPEG image with more +than four components. Because the out-of-bounds reference was still within the +same structure, it was not known to pose a security threat, but removing the +warning makes it easier to detect actual security issues, should they arise in +the future. + +10. Fixed another ABI conformance issue in the 64-bit ARM (AArch64) NEON SIMD +code. Some of the routines were incorrectly reading and storing data below the +stack pointer, which caused segfaults in certain applications under specific +circumstances. + + +1.5.0 +===== + +### Significant changes relative to 1.5 beta1: + +1. Fixed an issue whereby a malformed motion-JPEG frame could cause the "fast +path" of libjpeg-turbo's Huffman decoder to read from uninitialized memory. + +2. Added libjpeg-turbo version and build information to the global string table +of the libjpeg and TurboJPEG API libraries. This is a common practice in other +infrastructure libraries, such as OpenSSL and libpng, because it makes it easy +to examine an application binary and determine which version of the library the +application was linked against. + +3. Fixed a couple of issues in the PPM reader that would cause buffer overruns +in cjpeg if one of the values in a binary PPM/PGM input file exceeded the +maximum value defined in the file's header and that maximum value was greater +than 255. libjpeg-turbo 1.4.2 already included a similar fix for ASCII PPM/PGM +files. Note that these issues were not security bugs, since they were confined +to the cjpeg program and did not affect any of the libjpeg-turbo libraries. + +4. Fixed an issue whereby attempting to decompress a JPEG file with a corrupt +header using the `tjDecompressToYUV2()` function would cause the function to +abort without returning an error and, under certain circumstances, corrupt the +stack. This only occurred if `tjDecompressToYUV2()` was called prior to +calling `tjDecompressHeader3()`, or if the return value from +`tjDecompressHeader3()` was ignored (both cases represent incorrect usage of +the TurboJPEG API.) + +5. Fixed an issue in the ARM 32-bit SIMD-accelerated Huffman encoder that +prevented the code from assembling properly with clang. + +6. The `jpeg_stdio_src()`, `jpeg_mem_src()`, `jpeg_stdio_dest()`, and +`jpeg_mem_dest()` functions in the libjpeg API will now throw an error if a +source/destination manager has already been assigned to the compress or +decompress object by a different function or by the calling program. This +prevents these functions from attempting to reuse a source/destination manager +structure that was allocated elsewhere, because there is no way to ensure that +it would be big enough to accommodate the new source/destination manager. + + +1.4.90 (1.5 beta1) +================== + +### Significant changes relative to 1.4.2: + +1. Added full SIMD acceleration for PowerPC platforms using AltiVec VMX +(128-bit SIMD) instructions. Although the performance of libjpeg-turbo on +PowerPC was already good, due to the increased number of registers available +to the compiler vs. x86, it was still possible to speed up compression by about +3-4x and decompression by about 2-2.5x (relative to libjpeg v6b) through the +use of AltiVec instructions. + +2. Added two new libjpeg API functions (`jpeg_skip_scanlines()` and +`jpeg_crop_scanline()`) that can be used to partially decode a JPEG image. See +[libjpeg.txt](libjpeg.txt) for more details. + +3. The TJCompressor and TJDecompressor classes in the TurboJPEG Java API now +implement the Closeable interface, so those classes can be used with a +try-with-resources statement. + +4. The TurboJPEG Java classes now throw unchecked idiomatic exceptions +(IllegalArgumentException, IllegalStateException) for unrecoverable errors +caused by incorrect API usage, and those classes throw a new checked exception +type (TJException) for errors that are passed through from the C library. + +5. Source buffers for the TurboJPEG C API functions, as well as the +`jpeg_mem_src()` function in the libjpeg API, are now declared as const +pointers. This facilitates passing read-only buffers to those functions and +ensures the caller that the source buffer will not be modified. This should +not create any backward API or ABI incompatibilities with prior libjpeg-turbo +releases. + +6. The MIPS DSPr2 SIMD code can now be compiled to support either FR=0 or FR=1 +FPUs. + +7. Fixed additional negative left shifts and other issues reported by the GCC +and Clang undefined behavior sanitizers. Most of these issues affected only +32-bit code, and none of them was known to pose a security threat, but removing +the warnings makes it easier to detect actual security issues, should they +arise in the future. + +8. Removed the unnecessary `.arch` directive from the ARM64 NEON SIMD code. +This directive was preventing the code from assembling using the clang +integrated assembler. + +9. Fixed a regression caused by 1.4.1[6] that prevented 32-bit and 64-bit +libjpeg-turbo RPMs from being installed simultaneously on recent Red Hat/Fedora +distributions. This was due to the addition of a macro in jconfig.h that +allows the Huffman codec to determine the word size at compile time. Since +that macro differs between 32-bit and 64-bit builds, this caused a conflict +between the i386 and x86_64 RPMs (any differing files, other than executables, +are not allowed when 32-bit and 64-bit RPMs are installed simultaneously.) +Since the macro is used only internally, it has been moved into jconfigint.h. + +10. The x86-64 SIMD code can now be disabled at run time by setting the +`JSIMD_FORCENONE` environment variable to `1` (the other SIMD implementations +already had this capability.) + +11. Added a new command-line argument to TJBench (`-nowrite`) that prevents the +benchmark from outputting any images. This removes any potential operating +system overhead that might be caused by lazy writes to disk and thus improves +the consistency of the performance measurements. + +12. Added SIMD acceleration for Huffman encoding on SSE2-capable x86 and x86-64 +platforms. This speeds up the compression of full-color JPEGs by about 10-15% +on average (relative to libjpeg-turbo 1.4.x) when using modern Intel and AMD +CPUs. Additionally, this works around an issue in the clang optimizer that +prevents it (as of this writing) from achieving the same performance as GCC +when compiling the C version of the Huffman encoder +(<https://llvm.org/bugs/show_bug.cgi?id=16035>). For the purposes of +benchmarking or regression testing, SIMD-accelerated Huffman encoding can be +disabled by setting the `JSIMD_NOHUFFENC` environment variable to `1`. + +13. Added ARM 64-bit (ARMv8) NEON SIMD implementations of the commonly-used +compression algorithms (including the accurate integer forward DCT and h2v2 & +h2v1 downsampling algorithms, which are not accelerated in the 32-bit NEON +implementation.) This speeds up the compression of full-color JPEGs by about +75% on average on a Cavium ThunderX processor and by about 2-2.5x on average on +Cortex-A53 and Cortex-A57 cores. + +14. Added SIMD acceleration for Huffman encoding on NEON-capable ARM 32-bit +and 64-bit platforms. + + For 32-bit code, this speeds up the compression of full-color JPEGs by +about 30% on average on a typical iOS device (iPhone 4S, Cortex-A9) and by +about 6-7% on average on a typical Android device (Nexus 5X, Cortex-A53 and +Cortex-A57), relative to libjpeg-turbo 1.4.x. Note that the larger speedup +under iOS is due to the fact that iOS builds use LLVM, which does not optimize +the C Huffman encoder as well as GCC does. + + For 64-bit code, NEON-accelerated Huffman encoding speeds up the +compression of full-color JPEGs by about 40% on average on a typical iOS device +(iPhone 5S, Apple A7) and by about 7-8% on average on a typical Android device +(Nexus 5X, Cortex-A53 and Cortex-A57), in addition to the speedup described in +[13] above. + + For the purposes of benchmarking or regression testing, SIMD-accelerated +Huffman encoding can be disabled by setting the `JSIMD_NOHUFFENC` environment +variable to `1`. + +15. pkg-config (.pc) scripts are now included for both the libjpeg and +TurboJPEG API libraries on Un*x systems. Note that if a project's build system +relies on these scripts, then it will not be possible to build that project +with libjpeg or with a prior version of libjpeg-turbo. + +16. Optimized the ARM 64-bit (ARMv8) NEON SIMD decompression routines to +improve performance on CPUs with in-order pipelines. This speeds up the +decompression of full-color JPEGs by nearly 2x on average on a Cavium ThunderX +processor and by about 15% on average on a Cortex-A53 core. + +17. Fixed an issue in the accelerated Huffman decoder that could have caused +the decoder to read past the end of the input buffer when a malformed, +specially-crafted JPEG image was being decompressed. In prior versions of +libjpeg-turbo, the accelerated Huffman decoder was invoked (in most cases) only +if there were > 128 bytes of data in the input buffer. However, it is possible +to construct a JPEG image in which a single Huffman block is over 430 bytes +long, so this version of libjpeg-turbo activates the accelerated Huffman +decoder only if there are > 512 bytes of data in the input buffer. + +18. Fixed a memory leak in tjunittest encountered when running the program +with the `-yuv` option. + + +1.4.2 +===== + +### Significant changes relative to 1.4.1: + +1. Fixed an issue whereby cjpeg would segfault if a Windows bitmap with a +negative width or height was used as an input image (Windows bitmaps can have +a negative height if they are stored in top-down order, but such files are +rare and not supported by libjpeg-turbo.) + +2. Fixed an issue whereby, under certain circumstances, libjpeg-turbo would +incorrectly encode certain JPEG images when quality=100 and the fast integer +forward DCT were used. This was known to cause `make test` to fail when the +library was built with `-march=haswell` on x86 systems. + +3. Fixed an issue whereby libjpeg-turbo would crash when built with the latest +& greatest development version of the Clang/LLVM compiler. This was caused by +an x86-64 ABI conformance issue in some of libjpeg-turbo's 64-bit SSE2 SIMD +routines. Those routines were incorrectly using a 64-bit `mov` instruction to +transfer a 32-bit JDIMENSION argument, whereas the x86-64 ABI allows the upper +(unused) 32 bits of a 32-bit argument's register to be undefined. The new +Clang/LLVM optimizer uses load combining to transfer multiple adjacent 32-bit +structure members into a single 64-bit register, and this exposed the ABI +conformance issue. + +4. Fixed a bug in the MIPS DSPr2 4:2:0 "plain" (non-fancy and non-merged) +upsampling routine that caused a buffer overflow (and subsequent segfault) when +decompressing a 4:2:0 JPEG image whose scaled output width was less than 16 +pixels. The "plain" upsampling routines are normally only used when +decompressing a non-YCbCr JPEG image, but they are also used when decompressing +a JPEG image whose scaled output height is 1. + +5. Fixed various negative left shifts and other issues reported by the GCC and +Clang undefined behavior sanitizers. None of these was known to pose a +security threat, but removing the warnings makes it easier to detect actual +security issues, should they arise in the future. + + +1.4.1 +===== + +### Significant changes relative to 1.4.0: + +1. tjbench now properly handles CMYK/YCCK JPEG files. Passing an argument of +`-cmyk` (instead of, for instance, `-rgb`) will cause tjbench to internally +convert the source bitmap to CMYK prior to compression, to generate YCCK JPEG +files, and to internally convert the decompressed CMYK pixels back to RGB after +decompression (the latter is done automatically if a CMYK or YCCK JPEG is +passed to tjbench as a source image.) The CMYK<->RGB conversion operation is +not benchmarked. NOTE: The quick & dirty CMYK<->RGB conversions that tjbench +uses are suitable for testing only. Proper conversion between CMYK and RGB +requires a color management system. + +2. `make test` now performs additional bitwise regression tests using tjbench, +mainly for the purpose of testing compression from/decompression to a subregion +of a larger image buffer. + +3. `make test` no longer tests the regression of the floating point DCT/IDCT +by default, since the results of those tests can vary if the algorithms in +question are not implemented using SIMD instructions on a particular platform. +See the comments in [Makefile.am](Makefile.am) for information on how to +re-enable the tests and to specify an expected result for them based on the +particulars of your platform. + +4. The NULL color conversion routines have been significantly optimized, +which speeds up the compression of RGB and CMYK JPEGs by 5-20% when using +64-bit code and 0-3% when using 32-bit code, and the decompression of those +images by 10-30% when using 64-bit code and 3-12% when using 32-bit code. + +5. Fixed an "illegal instruction" error that occurred when djpeg from a +SIMD-enabled libjpeg-turbo MIPS build was executed with the `-nosmooth` option +on a MIPS machine that lacked DSPr2 support. The MIPS SIMD routines for h2v1 +and h2v2 merged upsampling were not properly checking for the existence of +DSPr2. + +6. Performance has been improved significantly on 64-bit non-Linux and +non-Windows platforms (generally 10-20% faster compression and 5-10% faster +decompression.) Due to an oversight, the 64-bit version of the accelerated +Huffman codec was not being compiled in when libjpeg-turbo was built on +platforms other than Windows or Linux. Oops. + +7. Fixed an extremely rare bug in the Huffman encoder that caused 64-bit +builds of libjpeg-turbo to incorrectly encode a few specific test images when +quality=98, an optimized Huffman table, and the accurate integer forward DCT +were used. + +8. The Windows (CMake) build system now supports building only static or only +shared libraries. This is accomplished by adding either `-DENABLE_STATIC=0` or +`-DENABLE_SHARED=0` to the CMake command line. + +9. TurboJPEG API functions will now return an error code if a warning is +triggered in the underlying libjpeg API. For instance, if a JPEG file is +corrupt, the TurboJPEG decompression functions will attempt to decompress +as much of the image as possible, but those functions will now return -1 to +indicate that the decompression was not entirely successful. + +10. Fixed a bug in the MIPS DSPr2 4:2:2 fancy upsampling routine that caused a +buffer overflow (and subsequent segfault) when decompressing a 4:2:2 JPEG image +in which the right-most MCU was 5 or 6 pixels wide. + + +1.4.0 +===== + +### Significant changes relative to 1.4 beta1: + +1. Fixed a build issue on OS X PowerPC platforms (md5cmp failed to build +because OS X does not provide the `le32toh()` and `htole32()` functions.) + +2. The non-SIMD RGB565 color conversion code did not work correctly on big +endian machines. This has been fixed. + +3. Fixed an issue in `tjPlaneSizeYUV()` whereby it would erroneously return 1 +instead of -1 if `componentID` was > 0 and `subsamp` was `TJSAMP_GRAY`. + +3. Fixed an issue in `tjBufSizeYUV2()` whereby it would erroneously return 0 +instead of -1 if `width` was < 1. + +5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting +on ARM64 platforms (see 1.4 beta1[5].) + +6. The `close()` method in the TJCompressor and TJDecompressor Java classes is +now idempotent. Previously, that method would call the native `tjDestroy()` +function even if the TurboJPEG instance had already been destroyed. This +caused an exception to be thrown during finalization, if the `close()` method +had already been called. The exception was caught, but it was still an +expensive operation. + +7. The TurboJPEG API previously generated an error (`Could not determine +subsampling type for JPEG image`) when attempting to decompress grayscale JPEG +images that were compressed with a sampling factor other than 1 (for instance, +with `cjpeg -grayscale -sample 2x2`). Subsampling technically has no meaning +with grayscale JPEGs, and thus the horizontal and vertical sampling factors +for such images are ignored by the decompressor. However, the TurboJPEG API +was being too rigid and was expecting the sampling factors to be equal to 1 +before it treated the image as a grayscale JPEG. + +8. cjpeg, djpeg, and jpegtran now accept an argument of `-version`, which will +print the library version and exit. + +9. Referring to 1.4 beta1[15], another extremely rare circumstance was +discovered under which the Huffman encoder's local buffer can be overrun +when a buffered destination manager is being used and an +extremely-high-frequency block (basically junk image data) is being encoded. +Even though the Huffman local buffer was increased from 128 bytes to 136 bytes +to address the previous issue, the new issue caused even the larger buffer to +be overrun. Further analysis reveals that, in the absolute worst case (such as +setting alternating AC coefficients to 32767 and -32768 in the JPEG scanning +order), the Huffman encoder can produce encoded blocks that approach double the +size of the unencoded blocks. Thus, the Huffman local buffer was increased to +256 bytes, which should prevent any such issue from re-occurring in the future. + +10. The new `tjPlaneSizeYUV()`, `tjPlaneWidth()`, and `tjPlaneHeight()` +functions were not actually usable on any platform except OS X and Windows, +because those functions were not included in the libturbojpeg mapfile. This +has been fixed. + +11. Restored the `JPP()`, `JMETHOD()`, and `FAR` macros in the libjpeg-turbo +header files. The `JPP()` and `JMETHOD()` macros were originally implemented +in libjpeg as a way of supporting non-ANSI compilers that lacked support for +prototype parameters. libjpeg-turbo has never supported such compilers, but +some software packages still use the macros to define their own prototypes. +Similarly, libjpeg-turbo has never supported MS-DOS and other platforms that +have far symbols, but some software packages still use the `FAR` macro. A +pretty good argument can be made that this is a bad practice on the part of the +software in question, but since this affects more than one package, it's just +easier to fix it here. + +12. Fixed issues that were preventing the ARM 64-bit SIMD code from compiling +for iOS, and included an ARMv8 architecture in all of the binaries installed by +the "official" libjpeg-turbo SDK for OS X. + + +1.3.90 (1.4 beta1) +================== + +### Significant changes relative to 1.3.1: + +1. New features in the TurboJPEG API: + + - YUV planar images can now be generated with an arbitrary line padding +(previously only 4-byte padding, which was compatible with X Video, was +supported.) + - The decompress-to-YUV function has been extended to support image +scaling. + - JPEG images can now be compressed from YUV planar source images. + - YUV planar images can now be decoded into RGB or grayscale images. + - 4:1:1 subsampling is now supported. This is mainly included for +compatibility, since 4:1:1 is not fully accelerated in libjpeg-turbo and has no +significant advantages relative to 4:2:0. + - CMYK images are now supported. This feature allows CMYK source images +to be compressed to YCCK JPEGs and YCCK or CMYK JPEGs to be decompressed to +CMYK destination images. Conversion between CMYK/YCCK and RGB or YUV images is +not supported. Such conversion requires a color management system and is thus +out of scope for a codec library. + - The handling of YUV images in the Java API has been significantly +refactored and should now be much more intuitive. + - The Java API now supports encoding a YUV image from an arbitrary +position in a large image buffer. + - All of the YUV functions now have a corresponding function that operates +on separate image planes instead of a unified image buffer. This allows for +compressing/decoding from or decompressing/encoding to a subregion of a larger +YUV image. It also allows for handling YUV formats that swap the order of the +U and V planes. + +2. Added SIMD acceleration for DSPr2-capable MIPS platforms. This speeds up +the compression of full-color JPEGs by 70-80% on such platforms and +decompression by 25-35%. + +3. If an application attempts to decompress a Huffman-coded JPEG image whose +header does not contain Huffman tables, libjpeg-turbo will now insert the +default Huffman tables. In order to save space, many motion JPEG video frames +are encoded without the default Huffman tables, so these frames can now be +successfully decompressed by libjpeg-turbo without additional work on the part +of the application. An application can still override the Huffman tables, for +instance to re-use tables from a previous frame of the same video. + +4. The Mac packaging system now uses pkgbuild and productbuild rather than +PackageMaker (which is obsolete and no longer supported.) This means that +OS X 10.6 "Snow Leopard" or later must be used when packaging libjpeg-turbo, +although the packages produced can be installed on OS X 10.5 "Leopard" or +later. OS X 10.4 "Tiger" is no longer supported. + +5. The Huffman encoder now uses `clz` and `bsr` instructions for bit counting +on ARM platforms rather than a lookup table. This reduces the memory footprint +by 64k, which may be important for some mobile applications. Out of four +Android devices that were tested, two demonstrated a small overall performance +loss (~3-4% on average) with ARMv6 code and a small gain (also ~3-4%) with +ARMv7 code when enabling this new feature, but the other two devices +demonstrated a significant overall performance gain with both ARMv6 and ARMv7 +code (~10-20%) when enabling the feature. Actual mileage may vary. + +6. Worked around an issue with Visual C++ 2010 and later that caused incorrect +pixels to be generated when decompressing a JPEG image to a 256-color bitmap, +if compiler optimization was enabled when libjpeg-turbo was built. This caused +the regression tests to fail when doing a release build under Visual C++ 2010 +and later. + +7. Improved the accuracy and performance of the non-SIMD implementation of the +floating point inverse DCT (using code borrowed from libjpeg v8a and later.) +The accuracy of this implementation now matches the accuracy of the SSE/SSE2 +implementation. Note, however, that the floating point DCT/IDCT algorithms are +mainly a legacy feature. They generally do not produce significantly better +accuracy than the accurate integer DCT/IDCT algorithms, and they are quite a +bit slower. + +8. Added a new output colorspace (`JCS_RGB565`) to the libjpeg API that allows +for decompressing JPEG images into RGB565 (16-bit) pixels. If dithering is not +used, then this code path is SIMD-accelerated on ARM platforms. + +9. Numerous obsolete features, such as support for non-ANSI compilers and +support for the MS-DOS memory model, were removed from the libjpeg code, +greatly improving its readability and making it easier to maintain and extend. + +10. Fixed a segfault that occurred when calling `output_message()` with +`msg_code` set to `JMSG_COPYRIGHT`. + +11. Fixed an issue whereby wrjpgcom was allowing comments longer than 65k +characters to be passed on the command line, which was causing it to generate +incorrect JPEG files. + +12. Fixed a bug in the build system that was causing the Windows version of +wrjpgcom to be built using the rdjpgcom source code. + +13. Restored 12-bit-per-component JPEG support. A 12-bit version of +libjpeg-turbo can now be built by passing an argument of `--with-12bit` to +configure (Unix) or `-DWITH_12BIT=1` to cmake (Windows.) 12-bit JPEG support +is included only for convenience. Enabling this feature disables all of the +performance features in libjpeg-turbo, as well as arithmetic coding and the +TurboJPEG API. The resulting library still contains the other libjpeg-turbo +features (such as the colorspace extensions), but in general, it performs no +faster than libjpeg v6b. + +14. Added ARM 64-bit SIMD acceleration for the YCC-to-RGB color conversion +and IDCT algorithms (both are used during JPEG decompression.) For unknown +reasons (probably related to clang), this code cannot currently be compiled for +iOS. + +15. Fixed an extremely rare bug (CVE-2014-9092) that could cause the Huffman +encoder's local buffer to overrun when a very high-frequency MCU is compressed +using quality 100 and no subsampling, and when the JPEG output buffer is being +dynamically resized by the destination manager. This issue was so rare that, +even with a test program specifically designed to make the bug occur (by +injecting random high-frequency YUV data into the compressor), it was +reproducible only once in about every 25 million iterations. + +16. Fixed an oversight in the TurboJPEG C wrapper: if any of the JPEG +compression functions was called repeatedly with the same +automatically-allocated destination buffer, then TurboJPEG would erroneously +assume that the `jpegSize` parameter was equal to the size of the buffer, when +in fact that parameter was probably equal to the size of the most recently +compressed JPEG image. If the size of the previous JPEG image was not as large +as the current JPEG image, then TurboJPEG would unnecessarily reallocate the +destination buffer. + + +1.3.1 +===== + +### Significant changes relative to 1.3.0: + +1. On Un*x systems, `make install` now installs the libjpeg-turbo libraries +into /opt/libjpeg-turbo/lib32 by default on any 32-bit system, not just x86, +and into /opt/libjpeg-turbo/lib64 by default on any 64-bit system, not just +x86-64. You can override this by overriding either the `prefix` or `libdir` +configure variables. + +2. The Windows installer now places a copy of the TurboJPEG DLLs in the same +directory as the rest of the libjpeg-turbo binaries. This was mainly done +to support TurboVNC 1.3, which bundles the DLLs in its Windows installation. +When using a 32-bit version of CMake on 64-bit Windows, it is impossible to +access the c:\WINDOWS\system32 directory, which made it impossible for the +TurboVNC build scripts to bundle the 64-bit TurboJPEG DLL. + +3. Fixed a bug whereby attempting to encode a progressive JPEG with arithmetic +entropy coding (by passing arguments of `-progressive -arithmetic` to cjpeg or +jpegtran, for instance) would result in an error, `Requested feature was +omitted at compile time`. + +4. Fixed a couple of issues (CVE-2013-6629 and CVE-2013-6630) whereby malformed +JPEG images would cause libjpeg-turbo to use uninitialized memory during +decompression. + +5. Fixed an error (`Buffer passed to JPEG library is too small`) that occurred +when calling the TurboJPEG YUV encoding function with a very small (< 5x5) +source image, and added a unit test to check for this error. + +6. The Java classes should now build properly under Visual Studio 2010 and +later. + +7. Fixed an issue that prevented SRPMs generated using the in-tree packaging +tools from being rebuilt on certain newer Linux distributions. + +8. Numerous minor fixes to eliminate compilation and build/packaging system +warnings, fix cosmetic issues, improve documentation clarity, and other general +source cleanup. + + +1.3.0 +===== + +### Significant changes relative to 1.3 beta1: + +1. `make test` now works properly on FreeBSD, and it no longer requires the +md5sum executable to be present on other Un*x platforms. + +2. Overhauled the packaging system: + + - To avoid conflict with vendor-supplied libjpeg-turbo packages, the +official RPMs and DEBs for libjpeg-turbo have been renamed to +"libjpeg-turbo-official". + - The TurboJPEG libraries are now located under /opt/libjpeg-turbo in the +official Linux and Mac packages, to avoid conflict with vendor-supplied +packages and also to streamline the packaging system. + - Release packages are now created with the directory structure defined +by the configure variables `prefix`, `bindir`, `libdir`, etc. (Un\*x) or by the +`CMAKE_INSTALL_PREFIX` variable (Windows.) The exception is that the docs are +always located under the system default documentation directory on Un\*x and +Mac systems, and on Windows, the TurboJPEG DLL is always located in the Windows +system directory. + - To avoid confusion, official libjpeg-turbo packages on Linux/Unix +platforms (except for Mac) will always install the 32-bit libraries in +/opt/libjpeg-turbo/lib32 and the 64-bit libraries in /opt/libjpeg-turbo/lib64. + - Fixed an issue whereby, in some cases, the libjpeg-turbo executables on +Un*x systems were not properly linking with the shared libraries installed by +the same package. + - Fixed an issue whereby building the "installer" target on Windows when +`WITH_JAVA=1` would fail if the TurboJPEG JAR had not been previously built. + - Building the "install" target on Windows now installs files into the +same places that the installer does. + +3. Fixed a Huffman encoder bug that prevented I/O suspension from working +properly. + + +1.2.90 (1.3 beta1) +================== + +### Significant changes relative to 1.2.1: + +1. Added support for additional scaling factors (3/8, 5/8, 3/4, 7/8, 9/8, 5/4, +11/8, 3/2, 13/8, 7/4, 15/8, and 2) when decompressing. Note that the IDCT will +not be SIMD-accelerated when using any of these new scaling factors. + +2. The TurboJPEG dynamic library is now versioned. It was not strictly +necessary to do so, because TurboJPEG uses versioned symbols, and if a function +changes in an ABI-incompatible way, that function is renamed and a legacy +function is provided to maintain backward compatibility. However, certain +Linux distro maintainers have a policy against accepting any library that isn't +versioned. + +3. Extended the TurboJPEG Java API so that it can be used to compress a JPEG +image from and decompress a JPEG image to an arbitrary position in a large +image buffer. + +4. The `tjDecompressToYUV()` function now supports the `TJFLAG_FASTDCT` flag. + +5. The 32-bit supplementary package for amd64 Debian systems now provides +symlinks in /usr/lib/i386-linux-gnu for the TurboJPEG libraries in /usr/lib32. +This allows those libraries to be used on MultiArch-compatible systems (such as +Ubuntu 11 and later) without setting the linker path. + +6. The TurboJPEG Java wrapper should now find the JNI library on Mac systems +without having to pass `-Djava.library.path=/usr/lib` to java. + +7. TJBench has been ported to Java to provide a convenient way of validating +the performance of the TurboJPEG Java API. It can be run with +`java -cp turbojpeg.jar TJBench`. + +8. cjpeg can now be used to generate JPEG files with the RGB colorspace +(feature ported from jpeg-8d.) + +9. The width and height in the `-crop` argument passed to jpegtran can now be +suffixed with `f` to indicate that, when the upper left corner of the cropping +region is automatically moved to the nearest iMCU boundary, the bottom right +corner should be moved by the same amount. In other words, this feature causes +jpegtran to strictly honor the specified width/height rather than the specified +bottom right corner (feature ported from jpeg-8d.) + +10. JPEG files using the RGB colorspace can now be decompressed into grayscale +images (feature ported from jpeg-8d.) + +11. Fixed a regression caused by 1.2.1[7] whereby the build would fail with +multiple "Mismatch in operand sizes" errors when attempting to build the x86 +SIMD code with NASM 0.98. + +12. The in-memory source/destination managers (`jpeg_mem_src()` and +`jpeg_mem_dest()`) are now included by default when building libjpeg-turbo with +libjpeg v6b or v7 emulation, so that programs can take advantage of these +functions without requiring the use of the backward-incompatible libjpeg v8 +ABI. The "age number" of the libjpeg-turbo library on Un*x systems has been +incremented by 1 to reflect this. You can disable this feature with a +configure/CMake switch in order to retain strict API/ABI compatibility with the +libjpeg v6b or v7 API/ABI (or with previous versions of libjpeg-turbo.) See +[README.md](README.md) for more details. + +13. Added ARMv7s architecture to libjpeg.a and libturbojpeg.a in the official +libjpeg-turbo binary package for OS X, so that those libraries can be used to +build applications that leverage the faster CPUs in the iPhone 5 and iPad 4. + + +1.2.1 +===== + +### Significant changes relative to 1.2.0: + +1. Creating or decoding a JPEG file that uses the RGB colorspace should now +properly work when the input or output colorspace is one of the libjpeg-turbo +colorspace extensions. + +2. When libjpeg-turbo was built without SIMD support and merged (non-fancy) +upsampling was used along with an alpha-enabled colorspace during +decompression, the unused byte of the decompressed pixels was not being set to +0xFF. This has been fixed. TJUnitTest has also been extended to test for the +correct behavior of the colorspace extensions when merged upsampling is used. + +3. Fixed a bug whereby the libjpeg-turbo SSE2 SIMD code would not preserve the +upper 64 bits of xmm6 and xmm7 on Win64 platforms, which violated the Win64 +calling conventions. + +4. Fixed a regression (CVE-2012-2806) caused by 1.2.0[6] whereby decompressing +corrupt JPEG images (specifically, images in which the component count was +erroneously set to a large value) would cause libjpeg-turbo to segfault. + +5. Worked around a severe performance issue with "Bobcat" (AMD Embedded APU) +processors. The `MASKMOVDQU` instruction, which was used by the libjpeg-turbo +SSE2 SIMD code, is apparently implemented in microcode on AMD processors, and +it is painfully slow on Bobcat processors in particular. Eliminating the use +of this instruction improved performance by an order of magnitude on Bobcat +processors and by a small amount (typically 5%) on AMD desktop processors. + +6. Added SIMD acceleration for performing 4:2:2 upsampling on NEON-capable ARM +platforms. This speeds up the decompression of 4:2:2 JPEGs by 20-25% on such +platforms. + +7. Fixed a regression caused by 1.2.0[2] whereby, on Linux/x86 platforms +running the 32-bit SSE2 SIMD code in libjpeg-turbo, decompressing a 4:2:0 or +4:2:2 JPEG image into a 32-bit (RGBX, BGRX, etc.) buffer without using fancy +upsampling would produce several incorrect columns of pixels at the right-hand +side of the output image if each row in the output image was not evenly +divisible by 16 bytes. + +8. Fixed an issue whereby attempting to build the SIMD extensions with Xcode +4.3 on OS X platforms would cause NASM to return numerous errors of the form +"'%define' expects a macro identifier". + +9. Added flags to the TurboJPEG API that allow the caller to force the use of +either the fast or the accurate DCT/IDCT algorithms in the underlying codec. + + +1.2.0 +===== + +### Significant changes relative to 1.2 beta1: + +1. Fixed build issue with Yasm on Unix systems (the libjpeg-turbo build system +was not adding the current directory to the assembler include path, so Yasm +was not able to find jsimdcfg.inc.) + +2. Fixed out-of-bounds read in SSE2 SIMD code that occurred when decompressing +a JPEG image to a bitmap buffer whose size was not a multiple of 16 bytes. +This was more of an annoyance than an actual bug, since it did not cause any +actual run-time problems, but the issue showed up when running libjpeg-turbo in +valgrind. See <http://crbug.com/72399> for more information. + +3. Added a compile-time macro (`LIBJPEG_TURBO_VERSION`) that can be used to +check the version of libjpeg-turbo against which an application was compiled. + +4. Added new RGBA/BGRA/ABGR/ARGB colorspace extension constants (libjpeg API) +and pixel formats (TurboJPEG API), which allow applications to specify that, +when decompressing to a 4-component RGB buffer, the unused byte should be set +to 0xFF so that it can be interpreted as an opaque alpha channel. + +5. Fixed regression issue whereby DevIL failed to build against libjpeg-turbo +because libjpeg-turbo's distributed version of jconfig.h contained an `INLINE` +macro, which conflicted with a similar macro in DevIL. This macro is used only +internally when building libjpeg-turbo, so it was moved into config.h. + +6. libjpeg-turbo will now correctly decompress erroneous CMYK/YCCK JPEGs whose +K component is assigned a component ID of 1 instead of 4. Although these files +are in violation of the spec, other JPEG implementations handle them +correctly. + +7. Added ARMv6 and ARMv7 architectures to libjpeg.a and libturbojpeg.a in +the official libjpeg-turbo binary package for OS X, so that those libraries can +be used to build both OS X and iOS applications. + + +1.1.90 (1.2 beta1) +================== + +### Significant changes relative to 1.1.1: + +1. Added a Java wrapper for the TurboJPEG API. See [java/README](java/README) +for more details. + +2. The TurboJPEG API can now be used to scale down images during +decompression. + +3. Added SIMD routines for RGB-to-grayscale color conversion, which +significantly improves the performance of grayscale JPEG compression from an +RGB source image. + +4. Improved the performance of the C color conversion routines, which are used +on platforms for which SIMD acceleration is not available. + +5. Added a function to the TurboJPEG API that performs lossless transforms. +This function is implemented using the same back end as jpegtran, but it +performs transcoding entirely in memory and allows multiple transforms and/or +crop operations to be batched together, so the source coefficients only need to +be read once. This is useful when generating image tiles from a single source +JPEG. + +6. Added tests for the new TurboJPEG scaled decompression and lossless +transform features to tjbench (the TurboJPEG benchmark, formerly called +"jpgtest".) + +7. Added support for 4:4:0 (transposed 4:2:2) subsampling in TurboJPEG, which +was necessary in order for it to read 4:2:2 JPEG files that had been losslessly +transposed or rotated 90 degrees. + +8. All legacy VirtualGL code has been re-factored, and this has allowed +libjpeg-turbo, in its entirety, to be re-licensed under a BSD-style license. + +9. libjpeg-turbo can now be built with Yasm. + +10. Added SIMD acceleration for ARM Linux and iOS platforms that support +NEON instructions. + +11. Refactored the TurboJPEG C API and documented it using Doxygen. The +TurboJPEG 1.2 API uses pixel formats to define the size and component order of +the uncompressed source/destination images, and it includes a more efficient +version of `TJBUFSIZE()` that computes a worst-case JPEG size based on the +level of chrominance subsampling. The refactored implementation of the +TurboJPEG API now uses the libjpeg memory source and destination managers, +which allows the TurboJPEG compressor to grow the JPEG buffer as necessary. + +12. Eliminated errors in the output of jpegtran on Windows that occurred when +the application was invoked using I/O redirection +(`jpegtran <input.jpg >output.jpg`.) + +13. The inclusion of libjpeg v7 and v8 emulation as well as arithmetic coding +support in libjpeg-turbo v1.1.0 introduced several new error constants in +jerror.h, and these were mistakenly enabled for all emulation modes, causing +the error enum in libjpeg-turbo to sometimes have different values than the +same enum in libjpeg. This represents an ABI incompatibility, and it caused +problems with rare applications that took specific action based on a particular +error value. The fix was to include the new error constants conditionally +based on whether libjpeg v7 or v8 emulation was enabled. + +14. Fixed an issue whereby Windows applications that used libjpeg-turbo would +fail to compile if the Windows system headers were included before jpeglib.h. +This issue was caused by a conflict in the definition of the INT32 type. + +15. Fixed 32-bit supplementary package for amd64 Debian systems, which was +broken by enhancements to the packaging system in 1.1. + +16. When decompressing a JPEG image using an output colorspace of +`JCS_EXT_RGBX`, `JCS_EXT_BGRX`, `JCS_EXT_XBGR`, or `JCS_EXT_XRGB`, +libjpeg-turbo will now set the unused byte to 0xFF, which allows applications +to interpret that byte as an alpha channel (0xFF = opaque). + + +1.1.1 +===== + +### Significant changes relative to 1.1.0: + +1. Fixed a 1-pixel error in row 0, column 21 of the luminance plane generated +by `tjEncodeYUV()`. + +2. libjpeg-turbo's accelerated Huffman decoder previously ignored unexpected +markers found in the middle of the JPEG data stream during decompression. It +will now hand off decoding of a particular block to the unaccelerated Huffman +decoder if an unexpected marker is found, so that the unaccelerated Huffman +decoder can generate an appropriate warning. + +3. Older versions of MinGW64 prefixed symbol names with underscores by +default, which differed from the behavior of 64-bit Visual C++. MinGW64 1.0 +has adopted the behavior of 64-bit Visual C++ as the default, so to accommodate +this, the libjpeg-turbo SIMD function names are no longer prefixed with an +underscore when building with MinGW64. This means that, when building +libjpeg-turbo with older versions of MinGW64, you will now have to add +`-fno-leading-underscore` to the `CFLAGS`. + +4. Fixed a regression bug in the NSIS script that caused the Windows installer +build to fail when using the Visual Studio IDE. + +5. Fixed a bug in `jpeg_read_coefficients()` whereby it would not initialize +`cinfo->image_width` and `cinfo->image_height` if libjpeg v7 or v8 emulation +was enabled. This specifically caused the jpegoptim program to fail if it was +linked against a version of libjpeg-turbo that was built with libjpeg v7 or v8 +emulation. + +6. Eliminated excessive I/O overhead that occurred when reading BMP files in +cjpeg. + +7. Eliminated errors in the output of cjpeg on Windows that occurred when the +application was invoked using I/O redirection (`cjpeg <inputfile >output.jpg`.) + + +1.1.0 +===== + +### Significant changes relative to 1.1 beta1: + +1. The algorithm used by the SIMD quantization function cannot produce correct +results when the JPEG quality is >= 98 and the fast integer forward DCT is +used. Thus, the non-SIMD quantization function is now used for those cases, +and libjpeg-turbo should now produce identical output to libjpeg v6b in all +cases. + +2. Despite the above, the fast integer forward DCT still degrades somewhat for +JPEG qualities greater than 95, so the TurboJPEG wrapper will now automatically +use the accurate integer forward DCT when generating JPEG images of quality 96 +or greater. This reduces compression performance by as much as 15% for these +high-quality images but is necessary to ensure that the images are perceptually +lossless. It also ensures that the library can avoid the performance pitfall +created by [1]. + +3. Ported jpgtest.cxx to pure C to avoid the need for a C++ compiler. + +4. Fixed visual artifacts in grayscale JPEG compression caused by a typo in +the RGB-to-luminance lookup tables. + +5. The Windows distribution packages now include the libjpeg run-time programs +(cjpeg, etc.) + +6. All packages now include jpgtest. + +7. The TurboJPEG dynamic library now uses versioned symbols. + +8. Added two new TurboJPEG API functions, `tjEncodeYUV()` and +`tjDecompressToYUV()`, to replace the somewhat hackish `TJ_YUV` flag. + + +1.0.90 (1.1 beta1) +================== + +### Significant changes relative to 1.0.1: + +1. Added emulation of the libjpeg v7 and v8 APIs and ABIs. See +[README.md](README.md) for more details. This feature was sponsored by +CamTrace SAS. + +2. Created a new CMake-based build system for the Visual C++ and MinGW builds. + +3. Grayscale bitmaps can now be compressed from/decompressed to using the +TurboJPEG API. + +4. jpgtest can now be used to test decompression performance with existing +JPEG images. + +5. If the default install prefix (/opt/libjpeg-turbo) is used, then +`make install` now creates /opt/libjpeg-turbo/lib32 and +/opt/libjpeg-turbo/lib64 sym links to duplicate the behavior of the binary +packages. + +6. All symbols in the libjpeg-turbo dynamic library are now versioned, even +when the library is built with libjpeg v6b emulation. + +7. Added arithmetic encoding and decoding support (can be disabled with +configure or CMake options) + +8. Added a `TJ_YUV` flag to the TurboJPEG API, which causes both the compressor +and decompressor to output planar YUV images. + +9. Added an extended version of `tjDecompressHeader()` to the TurboJPEG API, +which allows the caller to determine the type of subsampling used in a JPEG +image. + +10. Added further protections against invalid Huffman codes. + + +1.0.1 +===== + +### Significant changes relative to 1.0.0: + +1. The Huffman decoder will now handle erroneous Huffman codes (for instance, +from a corrupt JPEG image.) Previously, these would cause libjpeg-turbo to +crash under certain circumstances. + +2. Fixed typo in SIMD dispatch routines that was causing 4:2:2 upsampling to +be used instead of 4:2:0 when decompressing JPEG images using SSE2 code. + +3. The configure script will now automatically determine whether the +`INCOMPLETE_TYPES_BROKEN` macro should be defined. + + +1.0.0 +===== + +### Significant changes relative to 0.0.93: + +1. 2983700: Further FreeBSD build tweaks (no longer necessary to specify +`--host` when configuring on a 64-bit system) + +2. Created symlinks in the Unix/Linux packages so that the TurboJPEG +include file can always be found in /opt/libjpeg-turbo/include, the 32-bit +static libraries can always be found in /opt/libjpeg-turbo/lib32, and the +64-bit static libraries can always be found in /opt/libjpeg-turbo/lib64. + +3. The Unix/Linux distribution packages now include the libjpeg run-time +programs (cjpeg, etc.) and man pages. + +4. Created a 32-bit supplementary package for amd64 Debian systems, which +contains just the 32-bit libjpeg-turbo libraries. + +5. Moved the libraries from */lib32 to */lib in the i386 Debian package. + +6. Include distribution package for Cygwin + +7. No longer necessary to specify `--without-simd` on non-x86 architectures, +and unit tests now work on those architectures. + + +0.0.93 +====== + +### Significant changes since 0.0.91: + +1. 2982659: Fixed x86-64 build on FreeBSD systems + +2. 2988188: Added support for Windows 64-bit systems + + +0.0.91 +====== + +### Significant changes relative to 0.0.90: + +1. Added documentation to .deb packages + +2. 2968313: Fixed data corruption issues when decompressing large JPEG images +and/or using buffered I/O with the libjpeg-turbo decompressor + + +0.0.90 +====== + +Initial release |