kc3-lang/libjpeg-turbo

Log

Author Commit Date CI Message
DRC 47656a08 2023-10-02T18:03:50 Test: Fix float test errors w/ Clang & fp-contract The MD5 sums associated with FLOATTEST8=fp-contract and FLOATTEST12=fp-contract are appropriate for GCC (tested v5 through v13) with -ffp-contract=fast, which is the default when compiling for an architecture that has fused multiply-add (FMA) instructions. However, different MD5 sums are needed for Clang (tested v5 through v14) with -ffp-contract=on, which is now the default in Clang 14 when compiling for an architecture that has FMA instructions. Refer to #705, #709, #710
DRC c0412b56 2023-09-14T17:19:36 ChangeLog.md: List CVE ID fixed by ccaba5d7 Closes #724
DRC f3c7116e 2023-09-11T12:46:13 jpeglib.h: Document that JCS_RGB565 is decomp-only Closes #723
DRC 9b704f96 2023-08-15T11:03:57 Fix block smoothing w/vert.-subsampled prog. JPEGs The 5x5 interblock smoothing implementation, introduced in libjpeg-turbo 2.1, improperly extended the logic from the traditional 3x3 smoothing implementation. Both implementations point prev_block_row and next_block_row to the current block row when processing, respectively, the first and the last block row in the image: if (block_row > 0 || cinfo->output_iMCU_row > 0) prev_block_row = buffer[block_row - 1] + cinfo->master->first_MCU_col[ci]; else prev_block_row = buffer_ptr; if (block_row < block_rows - 1 || cinfo->output_iMCU_row < last_iMCU_row) next_block_row = buffer[block_row + 1] + cinfo->master->first_MCU_col[ci]; else next_block_row = buffer_ptr; 6d91e950c871103a11bac2f10c63bf998796c719 naively extended that logic to accommodate a 5x5 smoothing window: if (block_row > 1 || cinfo->output_iMCU_row > 1) prev_prev_block_row = buffer[block_row - 2] + cinfo->master->first_MCU_col[ci]; else prev_prev_block_row = prev_block_row; if (block_row < block_rows - 2 || cinfo->output_iMCU_row + 1 < last_iMCU_row) next_next_block_row = buffer[block_row + 2] + cinfo->master->first_MCU_col[ci]; else next_next_block_row = next_block_row; However, this new logic was only correct if block_rows == 1, so the values of prev_prev_block_row and next_next_block_row were incorrect when processing, respectively, the second and second to last iMCU rows in a vertically-subsampled progressive JPEG image. The intent was to: - point prev_block_row to the current block row when processing the first block row in the image, - point prev_prev_block_row to prev_block_row when processing the first two block rows in the image, - point next_block_row to the current block row when processing the last block row in the image, and - point next_next_block_row to next_block_row when processing the last two block rows in the image. This commit modifies decompress_smooth_data() so that it computes the current block row's position relative to the whole image and sets the block row pointers based on that value. This commit also restores a line of code that was accidentally deleted by 6d91e950c871103a11bac2f10c63bf998796c719: access_rows += compptr->v_samp_factor; /* prior iMCU row too */ access_rows is merely a sanity check that tells the access_virt_barray() method to generate an error if accessing the specified number of rows would cause a buffer overrun. Essentially, it is a belt-and-suspenders measure to ensure that j*init_d_coef_controller() allocated enough rows for the full-image virtual array. Thus, excluding that line of code did not cause an observable issue. This commit also documents dbae59281fdc6b3a6304a40134e8576d50d662c0 in the change log. Fixes #721
DRC 7b844bfd 2023-07-28T11:46:10 x86-64 SIMD: Use std stack frame/prologue/epilogue This allows debuggers and profilers to reliably capture backtraces from within the x86-64 SIMD functions. In places where rbp was previously used to access temporary variables (after stack alignment), we now use r15 and save/restore it accordingly. The total amount of work is approximately the same, because the previous code pushed the pre-alignment stack pointer to the aligned stack. The new prologue and epilogue actually have fewer instructions. Also note that the {un}collect_args macros now use rbp instead of rax to access arguments passed on the stack, so we save a few instructions there as well. Based on: https://github.com/alk/libjpeg-turbo/commit/debcc7c3b436467aea8d02c66a514c5099d0ad37 Closes #707 Closes #708
DRC e17fa3a2 2023-07-27T13:11:39 Bump version to 3.0.1 to prepare for new commits
DRC dbae5928 2023-08-03T14:42:30 Fix interblock smoothing with narrow prog. JPEGs Due to an oversight, the assignment of DC05, DC10, DC15, DC20, and DC25 (the right edge coefficients in the 5x5 interblock smoothing window) in decompress_smooth_data() was incorrect for images exactly two MCU blocks wide. For such images, DC04, DC09, DC14, DC19, and DC24 were assigned values based on the last MCU column, but DC05, DC10, DC15, DC20, and DC25 were assigned values based on the first MCU column (because block_num + 1 was never less than last_block_column.) This commit modifies jdcoefct.c so that, for images at least two MCU blocks wide, DC05, DC10, DC15, DC20, and DC25 are assigned the same values as DC04, DC09, DC14, DC19, and DC24 (respectively.) DC05, DC10, DC15, DC20, and DC25 are then immediately overwritten for images more than two MCU blocks wide. Since this issue was minor and not likely obvious to an end user, the fix is undocumented. Fixes #700
DRC 300a344d 2023-07-30T11:02:29 tjexample.c: Fix error when recompressing (regression introduced by fc01f4673b71c0b833c59c21e8c4478a9c4bcf21) Because of the TurboJPEG 3 API overhaul, the pure compression code path in tjexample.c now creates a TurboJPEG compression instance prior to calling tj3LoadImage(). However, due to an oversight, a compression instance was no longer created in the recompression code path. Thus, that code path attempted to reuse the TurboJPEG decompression instance, which caused an error ("tj3Set(): TJPARAM_QUALITY is not applicable to decompression instances.") This commit modifies tjexample.c so that the recompression code path creates a new TurboJPEG compression instance if one has not already been created. Fixes #716
DRC ebca79d5 2023-07-25T16:46:07 xform fuzz: Test optimized baseline entropy coding Because of d011622f4b5b2c3f0141e93fc3e1da6169915c18, optimized baseline entropy coding wasn't actually being tested.
DRC 63bd7188 2023-07-25T10:01:42 Build: Unset FLOATTEST* by default for non-x86 Because libjpeg-turbo 3.0.x now supports multiple data precisions in the same build, the regression test system can test the 8-bit and 12-bit floating point DCT/IDCT algorithms separately. The expected MD5 sums for those tests are communicated to the test system using the FLOATTEST8 and FLOATTEST12 CMake variables. Whereas it is possible to intelligently set a default value for FLOATTEST8 when building for x86[-64] and a default value for FLOATTEST12 when building for x86-64, it is not possible with other architectures. (Refer to #705, #709, and #710.) Clang 14, for example, now enables FMA (fused multiply-add) instructions by default on architectures that support them, but with AArch64 builds, the results are not the same as when using GCC/AArch64 with FMA instructions enabled. Thus, setting FLOATTEST12=fp-contract doesn't make the tests pass. It was already impossible to intelligently set a default for FLOATTEST8 with i386 builds, but referring to #710, that appears to be the case with other non-x86-64 builds as well. Back in 1991, when Tom Lane first released libjpeg, some CPUs had floating point units and some didn't. It could take minutes to compress or decompress a 1-megapixel JPEG image using the "slow" integer DCT/IDCT algorithms, and the floating point algorithms were significantly faster on systems that had an FPU. On systems without FPUs, floating point math was emulated and really slow, so Tom also developed "fast" integer DCT/IDCT algorithms to speed up JPEG performance, at the expense of accuracy, on those systems. Because of libjpeg-turbo's SIMD extensions, the floating point algorithms are now significantly slower than the "slow" integer algorithms without being significantly more accurate, and the "fast" integer algorithms fail the ISO/ITU-T conformance tests without being any faster than the "slow" integer algorithms on x86 systems. Thus, the floating point and "fast" integer algorithms are considered legacy features. In order for the floating point regression tests to be useful, the results of the tests must be validated against an independent metric. (In other words, it wouldn't be useful to use the floating point DCT/IDCT algorithms to determine the expected results of the floating point DCT/IDCT algorithms.) In the past, I attempted without success to develop a low-level floating point test that would run at configure time and determine the appropriate default value of FLOATTEST*. Barring that approach, the only other possibilities would be: 1. Develop a test framework that compares the floating point results with a margin of error, as TJUnitTest does. However, that effort isn't justified unless it could also benefit non-legacy features. 2. Compare the floating point results against an expected MD5 sum, as we currently do. However, as previously described, it isn't possible in most cases to determine an appropriate default value for the expected MD5 sum. For the moment, it makes the most sense to disable the 8-bit floating point tests by default except with x86[-64] builds and to disable the 12-bit floating point tests by default except with x86-64 builds. That means that the floating point algorithms will still be regression tested when performing x86[-64] builds, but other types of builds will have to opt in to the same regression tests. Since the floating point DCT/IDCT algorithms are unlikely to change ever again (the only reason they still exist at all is to maintain backward compatibility with libjpeg), this seems like a reasonable tradeoff.
DRC d6914b6b 2023-07-24T16:41:18 CMakeLists.txt: Fix comment buglet
DRC e429e379 2023-07-06T16:58:20 tjunittest.c: Use _getpid() on Windows
DRC 035ea386 2023-07-06T12:04:22 Build: Fix regression test concurrency issues - The example-*bit-*-decompress test must run after the example-*bit-*-compress test, since the latter generates testout*-example.jpg. - Add -static to the filenames of all output files generated by the "static" regression tests, to avoid conflicts with the "shared" regression tests. - Add the PID to the filenames of all files generated by the tjunittest packed-pixel image I/O tests. - Check the return value of MD5File() in tjunittest to avoid a segfault if the file doesn't exist. (Prior to the fix described above, that could occur if two instances of tjunittest ran concurrently from the same directory with the same -bmp and -precision arguments.) Fixes #705
DRC d011622f 2023-07-06T10:29:27 Restore xform fuzzer behavior from before c8d52f1c The intent was for the final transform operation to be the same as the first transform operation but without TJXOPT_COPYNONE or TJPARAM_NOREALLOC. Unrolling the transform operations in c8d52f1c4c7480277b91420c27b2548d4c8e9043 accidentally changed that.
DRC 89528757 2023-07-05T15:35:21 xform fuzz: Use src subsamp to calc dst buf size Referring to https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=60379 there are some specially-crafted malformed JPEG images that, when transformed to grayscale, will exceed the worst-case transformed grayscale JPEG image size. This is similar in nature to the issue fixed by c8d52f1c4c7480277b91420c27b2548d4c8e9043, except that in this case, the issue occurs regardless of the amount of metadata in the source image. Also, the tj3Transform() function, the Java_org_libjpegturbo_turbojpeg_TJTransformer_transform() JNI function, and TJBench were behaving correctly in this case, because the TurboJPEG API documentation specifies that the source image's subsampling type should be used when computing the worst-case transformed JPEG image size. (However, only the Java API documentation specified that. Oops. The C API documentation now does as well.) The documented usage mitigates the issue, and only the transform fuzzer did not adhere to that. Thus, this was an issue with the fuzzer itself rather than an issue with the library.
DRC 30c21e55 2023-07-05T13:51:35 OSS-Fuzz: Ignore tj3DecompressHeader() return val Unlike its predecessors, tj3DecompressHeader() does not fail if passed a JPEG image with an unknown subsampling type. This led me to believe that it was OK for the fuzzers to abort if tj3DecompressHeader() returned an error. However, there are apparently some malformed JPEG images that can expose issues in libjpeg-turbo while also causing tj3DecompressHeader() to complain about header errors. Thus, it is best to ignore the return value of tj3DecompressHeader(), as the fuzzers in libjpeg-turbo 2.1.x and prior did.
DRC 926f1f3d 2023-07-05T12:41:32 README.md: Include GitHub Sponsors link/button Closes #706
DRC 762f8b4f 2023-07-05T10:55:07 Doc: Mention that we are a JPEG ref implementation
DRC 6c87537f 2023-07-03T10:25:24 AppVeyor: Use SignPath release cert/only sign tags The SignPath release certificate for our project is not yet available as of this writing, but this commit prepares the CI system to use the release certificate whenever it becomes available. It also restricts signing only to tags, which correspond to official releases. (That mimics our traditional policy of not signing pre-release builds.)
DRC 02b074fd 2023-07-01T08:09:23 xform fuzz: Use only xform opts to set entropy alg This is subtle, but the tj3DecompressHeader() function sets the values of TJPARAM_ARITHMETIC, TJPARAM_OPTIMIZE, and TJPARAM_PROGRESSIVE. Unless we unset those values, the entropy algorithm used in the transformed JPEG image will be determined by the union of the parameter values and the transform options, which isn't what we want.
DRC e0c53aa3 2023-06-30T17:58:45 jchuff.c: Test for out-of-range coefficients Restore two coefficient range checks from libjpeg to the C baseline Huffman encoder. This fixes an issue (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=60253) whereby the encoder could read from uninitialized memory when attempting to transform a specially-crafted malformed arithmetic-coded JPEG source image into a baseline Huffman-coded JPEG destination image with default Huffman tables. More specifically, the out-of-range coefficients caused r to equal 256, which overflowed the actbl->ehufsi[] array. Because the overflow was contained within the huff_entropy_encoder structure, this issue was not exploitable (nor was it observable at all on x86 or Arm CPUs unless JSIMD_NOHUFFENC=1 or JSIMD_FORCENONE=1 was set in the environment or unless libjpeg-turbo was built with WITH_SIMD=0.) The fix is performance-neutral (+/- 1-2%) for x86-64 code and causes a 0-4% (avg. 1-2%, +/- 1-2%) compression regression for i386 code on Intel CPUs when the C baseline Huffman encoder is used (JSIMD_NOHUFFENC=1). The fix is performance-neutral (+/- 1-2%) on Intel CPUs when all of the libjpeg-turbo SIMD extensions are disabled (JSIMD_FORCENONE=1). The fix causes a 0-2% (avg. <1%, +/- 1%) compression regression for PowerPC code.
DRC 4a831d6e 2023-06-30T10:15:40 turbojpeg.h: Make customFilter() proto match doc Closes #704
DRC 240a5a5c 2023-06-29T17:45:07 ChangeLog.md: Fix typo
DRC 71738892 2023-06-29T16:31:37 djpeg: Fix -map option with 12-bit data precision
DRC bf9f319c 2023-06-29T16:07:42 Disallow color quantization with lossless decomp Color quantization is a legacy feature that serves little or no purpose with lossless JPEG images. 9f756bc67a84d4566bf74a0c2432aa55da404021 eliminated interaction issues between the lossless decompressor and the color quantizers related to out-of-range 12-bit samples, but referring to #701, other interaction issues apparently still exist. Such issues are likely, given the fact that the color quantizers were not designed with lossless decompression in mind. This commit reverts 9f756bc67a84d4566bf74a0c2432aa55da404021, since the issues it fixed are no longer relevant because of this commit and 2192560d74e6e6cf99dd05928885573be00a8208. Fixed #672 Fixes #673 Fixes #674 Fixes #676 Fixes #677 Fixes #678 Fixes #679 Fixes #681 Fixes #683 Fixes #701
DRC c8d52f1c 2023-06-26T11:53:03 tj3Transform: Calc dst buf size from xformed dims When used with TJPARAM_NOREALLOC and with TJXOP_TRANSPOSE, TJXOP_TRANSVERSE, TJXOP_ROT90, or TJXOP_ROT270, tj3Transform() incorrectly based the destination buffer size for a transform on the source image dimensions rather than the transformed image dimensions. This was apparently a long-standing bug that had existed in the tj*Transform() function since its inception. As initially implemented in the evolving libjpeg-turbo v1.2 code base, tjTransform() required dstSizes[i] to be set regardless of whether TJFLAG_NOREALLOC (the predecessor to TJPARAM_NOREALLOC) was set. ff78e37595c8462f64fd100f928aa1d08539527e, which was introduced later in the evolving libjpeg-turbo v1.2 code base, removed that requirement and planted the seed for the bug. However, the bug was not activated until 9b49f0e4c77c727648c6d3a4915eefdf5436de4a was introduced still later in the evolving libjpeg-turbo v1.2 code base, adding a subsampling type argument to the (new at the time) tjBufSize() function and thus making the width and height arguments no longer commutative. The bug opened up the possibility that a JPEG source image could cause tj3Transform() to overflow the destination buffer for a transform if all of the following were true: - The JPEG source image used 4:2:2, 4:4:0, 4:1:1, or 4:4:1 subsampling. (These are the only subsampling types for which the width and height arguments to tj3JPEGBufSize() are not commutative.) - The width and height of the JPEG source image were such that tj3JPEGBufSize(height, width, subsamplingType) returned a smaller value than tj3JPEGBufSize(width, height, subsamplingType). - The JPEG source image contained enough metadata that the size of the transformed image was larger than tj3JPEGBufSize(height, width, subsamplingType). - TJPARAM_NOREALLOC was set. - TJXOP_TRANSPOSE, TJXOP_TRANSVERSE, TJXOP_ROT90, or TJXOP_ROT270 was used. - TJXOPT_COPYNONE was not set. - TJXOPT_CROP was not set. - The calling program allocated tj3JPEGBufSize(height, width, subsamplingType) bytes for the destination buffer, as the API documentation instructs. The API documentation cautions that JPEG source images containing a large amount of extraneous metadata (EXIF, IPTC, ICC, etc.) cannot reliably be transformed if TJPARAM_NOREALLOC is set and TJXOPT_COPYNONE is not set. Irrespective of the bug, there are still cases in which a JPEG source image with a large amount of metadata can, when transformed, exceed the worst-case transformed JPEG image size. For instance, if you try to losslessly crop a JPEG image with 3 kB of EXIF data to 16x16 pixels, then you are guaranteed to exceed the worst-case 16x16 JPEG image size unless you discard the EXIF data. Even without the bug, tj3Transform() will still fail with "Buffer passed to JPEG library is too small" when attempting to transform JPEG source images that meet the aforementioned criteria. The bug is that the function segfaults rather than failing gracefully, but the chances of that occurring in a real-world application are very slim. Any real-world application developers who attempted to transform arbitrary JPEG source images with TJPARAM_NOREALLOC set would very quickly realize that they cannot reliably do that without also setting TJXOPT_COPYNONE. Thus, I posit that the actual risk posed by this bug is low. Applications such as web browsers that are the most exposed to security risks from arbitrary JPEG source images do not use the TurboJPEG lossless transform feature. (None of those applications even use the TurboJPEG API, to the best of my knowledge, and the public libjpeg API has no equivalent transform function.) Our only command-line interface to the tj3Transform() function, TJBench, was not exposed to the bug because it had a compatible bug whereby it allocated the JPEG destination buffer to the same size that tj3Transform() erroneously expected. The TurboJPEG Java API was also not exposed to the bug because of a similar compatible bug in the Java_org_libjpegturbo_turbojpeg_TJTransformer_transform() JNI function. (This commit fixes both compatible bugs.) In short, best practices for tj3Transform() are to use TJPARAM_NOREALLOC only with JPEG source images that are known to be free of metadata (such as images generated by tj3Compress*()) or to use TJXOPT_COPYNONE along with TJPARAM_NOREALLOC. Still, however, the function shouldn't segfault as long as the calling program allocates the suggested amount of space for the JPEG destination buffer. Usability notes: tj3Transform() could hypothetically require dstSizes[i] to be set regardless of the value of TJPARAM_NOREALLOC, but there are usability pitfalls either way. The main pitfall I sought to avoid with ff78e37595c8462f64fd100f928aa1d08539527e was a calling program failing to set dstSizes[i] at all, thus leaving its value undefined. It could be argued that requiring dstSizes[i] to be set in all cases is more consistent, but it could also be argued that not requiring it to be set when TJPARAM_NOREALLOC is set is more user-proof. tj3Transform() could also hypothetically set TJXOPT_COPYNONE automatically when TJPARAM_NOREALLOC is set, but that could lead to user confusion. Ultimately, I would like to address these issues in TurboJPEG v4 by using managed buffer objects, but that would be an extensive overhaul.
DRC 6b9e3b04 2023-06-19T11:11:16 README.md: Include link to project home page (for compliance with SignPath's Code of Conduct for Open Source projects)
DRC 41b18e8d 2023-06-18T12:50:47 AppVeyor: Only add installers to zip file Oops
DRC a403ad5b 2023-06-16T15:20:29 AppVeyor: Integrate with SignPath.io
DRC c27695a1 2023-06-16T11:20:15 Fix build warnings/errs w/ -DNO_GETENV/-DNO_PUTENV - strtest.c: Fix unused variable warnings if both -DNO_GETENV and -DNO_PUTENV are specified or if only -DNO_GETENV is specified. - jinclude.h: Fix build error if only -DNO_GETENV is specified. Fixes #697
DRC 65a85ce3 2023-06-16T11:16:08 GitHub: Fix x32 build 1f55ae7b0fa3acc348a630171617d0e56d922b68 accidentally overrode the value of CMAKE_C_FLAGS, thus eliminating the -mx32 flag that was necessary to enable x32.
DRC 0e9683c4 2023-06-12T14:36:18 Bump version to 3.0.0
DRC 6b506ed3 2023-06-01T13:11:14 tjexample.c: Prevent integer overflow Because width, height, and tjPixelSize[] are signed integers, signed integer overflow will occur if width * height * tjPixelSize[pixelFormat] > INT_MAX, which would cause an incorrect value to be passed to tj3Alloc(). This commit modifies tjexample.c in the following ways: - Implicitly promote width, height, and tjPixelSize[pixelFormat] to size_t before multiplying them. - Use malloc() rather than tj3Alloc() to allocate the uncompressed image buffer. (tj3Alloc() is only necessary for JPEG buffers that will potentially be reallocated by the TurboJPEG API library.) - If size_t is 32-bit, throw an error if width * height * tjPixelSize[pixelFormat] would overflow the data type. Since tjexample is not installed or packaged, the worst case for this issue was that a downstream application might interpret tjexample.c literally and introduce a similar overflow issue into its own code. However, it's worth noting that such issues could also be introduced when using malloc().
DRC 2192560d 2023-05-31T13:02:42 Disallow merged upsampling with lossless decomp Colorspace conversion is explicitly not supported with lossless JPEG images. Merged upsampling implies YCbCr-to-RGB colorspace conversion, so allowing it with lossless decompression was an oversight. 9f756bc67a84d4566bf74a0c2432aa55da404021 eliminated interaction issues between the lossless decompressor and the merged upsampler related to out-of-range 12-bit samples, but referring to #690, other interaction issues apparently still exist. Such issues are likely, given the fact that the merged upsampler was never designed with lossless decompression in mind. This commit also extends the decompress fuzzer so that it catches the issue reported in #690. Fixes #690 Redundantly fixes #670 Redundantly fixes #675
DRC 4e7ff7b9 2023-05-31T10:24:04 SECURITY.md: Wordsmithing and clarifications - Clarify that encrypted e-mail is optional. - Mention the new GitHub security advisory system. - Clarify that vulnerabilities against new features that are not yet in a Stable release series need not be reported securely.
DRC 10693e64 2023-05-30T18:22:50 GitHub: Add security policy
DRC 36aaeebb 2023-05-30T17:46:58 ChangeLog.md: List CVE ID fixed by 9f756bc6
DRC 3a536273 2023-04-06T18:33:41 jpeg_crop_scanline: Fix calc w/sclg + 2x4,4x2 samp When computing the downsampled width for a particular component, jpeg_crop_scanline() needs to take into account the fact that the libjpeg code uses a combination of IDCT scaling and upsampling to implement 4x2 and 2x4 upsampling with certain decompression scaling factors. Failing to account for that led to incomplete upsampling of 4x2- or 2x4-subsampled components, which caused the color converter to read from uninitialized memory. With 12-bit data precision, this caused a buffer overrun or underrun and subsequent segfault if the uninitialized memory contained a value that was outside of the valid sample range (because the color converter uses the value as an array index.) Fixes #669
DRC 62590d42 2023-04-04T19:06:20 Decomp: Don't enable 2-pass color quant w/ RGB565 The 2-pass color quantization algorithm assumes 3-sample pixels. RGB565 is the only 3-component colorspace that doesn't have 3-sample pixels, so we need to treat it as a special case when determining whether to enable 2-pass color quantization. Otherwise, attempting to initialize 2-pass color quantization with an RGB565 output buffer could cause prescan_quantize() to read from uninitialized memory and subsequently underflow/overflow the histogram array. djpeg is supposed to fail gracefully if both -rgb565 and -colors are specified, because none of its destination managers (image writers) support color quantization with RGB565. However, prescan_quantize() was called before that could occur. It is possible but very unlikely that these issues could have been reproduced in applications other than djpeg. The issues involve the use of two features (12-bit precision and RGB565) that are incompatible, and they also involve the use of two rarely-used legacy features (RGB565 and color quantization) that don't make much sense when combined. Fixes #668 Fixes #671 Fixes #680
DRC 9f756bc6 2023-04-04T13:53:21 Lossless decomp: Range-limit 12-bit samples 12-bit is the only data precision for which the range of the sample data type exceeds the valid sample range, so it is possible to craft a 12-bit lossless JPEG image that contains out-of-range 12-bit samples. Attempting to decompress such an image using color quantization or merged upsampling (NOTE: libjpeg-turbo cannot generate YCbCr or subsampled lossless JPEG images, but it can decompress them) caused segfaults or buffer overruns when those algorithms attempted to use the out-of-range sample values as array indices. This commit modifies the lossless decompressor so that it range-limits the output of the scaler when using 12-bit samples. Fixes #670 Fixes #672 Fixes #673 Fixes #674 Fixes #675 Fixes #676 Fixes #677 Fixes #678 Fixes #679 Fixes #681 Fixes #683
DRC 3f43c6a3 2023-04-04T13:27:11 jdlossls.c: Code formatting tweak
DRC d491094b 2023-04-03T12:31:40 Build separate static/shared jpeg12/16 obj libs If PIC isn't enabled for the entire build (using CMAKE_POSITION_INDEPENDENT_CODE), then we need to enable it for any of the objects in the libjpeg-turbo shared libraries. Ideally, however, we don't want to enable PIC for any of the objects in the libjpeg-turbo static libraries, unless CMAKE_POSITION_INDEPENDENT_CODE is set. Thus, we need to build separate static and shared jpeg12 and jpeg16 object libraries. Fixes #684
DRC 0d20aa15 2023-03-31T10:53:29 TJBench: Require known subsamp type w/tiled decomp (oversight from 386ec0abc7768922b0c51c3dc2e6efaff6278174) Tiled decompression will ultimately fail if the subsampling type of the JPEG input image is unknown, but the C version of TJBench needs to fail earlier in order to avoid using -1 (TJSAMP_UNKNOWN) as an array index for tjMCUWidth[]/tjMCUHeight[]. The Java version now fails earlier as well, although there is no benefit to that other than making the error message less cryptic.
DRC cc8c6d36 2023-03-13T14:10:48 tjbenchtest: Test all subsampling types
DRC 9d2f189c 2023-03-13T16:36:04 TJBench: Change subsamp for transposed 4:*:1 img If we have transformed a 4:1:1 or 4:4:1 JPEG input image in such a way that the horizontal and vertical dimensions are transposed, then we need to change the subsampling type that is passed to the decomp() function. Otherwise, tj3YUVBufSize() may return an incorrect value. (oversight from fc881ebb211b2ba6292d35691a946e1f9c1374b4)
DRC 386ec0ab 2023-03-13T13:11:19 TJBench: w/JPEG input imgs, set min tile= MCU size When -tile is used with a JPEG input image, TJBench generates the tiles using lossless cropping, which will fail if the cropping region doesn't align with an MCU boundary. Furthermore, there is no reason to avoid 8x8 tiles when decompressing 4:4:4 or grayscale JPEG images.
DRC fc881ebb 2023-03-09T20:55:43 TurboJPEG: Implement 4:4:1 chrominance subsampling This allows losslessly transposed or rotated 4:1:1 JPEG images to be losslessly cropped, partially decompressed, or decompressed to planar YUV images. Because tj3Transform() allows multiple lossless transformations to be chained together, all subsampling options need to have a corresponding transposed subsampling option. (This is why 4:4:0 was originally implemented as well.) Otherwise, the documentation would be technically incorrect. It says that images with unknown subsampling types cannot be losslessly cropped, partially decompressed, or decompressed to planar YUV images, but it doesn't say anything about images with known subsampling types whose subsampling type becomes unknown if the image is rotated or transposed. This is one of those situations in which it is easier to implement a feature that works around the problem than to document the problem. Closes #659
DRC 58a3427f 2023-03-09T21:07:40 Bump version to 2.1.92 to prepare for new commits
DRC 0827eaff 2023-03-09T21:04:40 ChangeLog.md: Add literal vers # to 3.0 beta2 hdr (per our convention)
DRC 97df8ea9 2023-02-23T11:40:59 GitHub: Add pull request template
DRC c13fe159 2023-02-23T09:35:12 Build: Clarify CMAKE_OSX_ARCHITECTURES error It's not that the build system doesn't support multiple values in CMAKE_OSX_ARCHITECTURES. It's that libjpeg-turbo, because of its SIMD extensions, *cannot* support multiple values in CMAKE_OSX_ARCHITECTURES.
DRC d67edaff 2023-02-10T10:40:56 Ignore 2.1.5.1 ChangeLog header w/git diff --check (Otherwise, checkstyle flags it as a leftover conflict marker.)
DRC 2af984fd 2023-02-10T09:55:27 Build: Fail if included with add_subdirectory() Even though BUILDING.md and CONTRIBUTING.md explicitly state that the libjpeg-turbo build system does not and will not support being integrated into downstream build systems using add_subdirectory() (see 05655481917a2d2761cf2fe19b76f639b7f159ef), people continue to file bug reports, feature requests, and pull requests regarding that (see #265, #637, and #653 in addition to the issues listed in 05655481917a2d2761cf2fe19b76f639b7f159ef.) Responding to those issues wastes our project's limited resources. Hopefully people will get the hint if the build system explicitly tells them that it can't be included using add_subdirectory(), which will prompt them to read the comments in CMakeLists.txt explaining why. To anyone stumbling upon this commit message, please refer to the discussions under the issues listed above, as well as the issues listed in 05655481917a2d2761cf2fe19b76f639b7f159ef. Our project's position on this has been stated, explained, and defended numerous times.
DRC 6c610333 2023-02-08T09:23:51 ChangeLog.md: Document 4e028ecd + bump version to 3.0 beta2
DRC 2a5a3c6f 2023-02-07T13:13:24 OSS-Fuzz: Bail out immediately on decomp failure Don't keep trying to decompress the same image if tj3Decompress*() has already thrown an error. Otherwise, if the image has an excessive number of scans, then each iteration of the loop will try to decompress up to the scan limit, which may cause the overall test to time out even if one iteration doesn't time out.
DRC 4e028ecd 2023-02-02T08:55:37 SIMD/x86: Initialize simd_support before every use As long as a libjpeg instance is only used by one thread at a time, a program is technically within its rights to call jpeg_start_*compress() in one thread and jpeg_(read|write)_*(), with the same libjpeg instance, in a second thread. However, because the various jsimd_can*() functions are called within the body of jpeg_start_*compress() and simd_support is now thread-local (due to f579cc11b33e5bfeb9931e37cc74b4a33c95d2e6), that led to a situation in which simd_support was initialized in the first thread but not the second. The uninitialized value of simd_support is 0xFFFFFFFF, which the second thread interpreted to mean that it could use any instruction set, and when it attempted to use AVX2 instructions on a CPU that didn't support them, an illegal instruction error occurred. This issue was known to affect libvips. This commit modifies the i386 and x86-64 SIMD dispatchers so that the various jsimd_*() functions always call init_simd(), if simd_support is uninitialized, prior to dispatching based on the value of simd_support. Note that the other SIMD dispatchers don't need this, because only the x86 SIMD extensions currently support multiple instruction sets. This patch has been verified to be performance-neutral to within +/- 0.4% with 32-bit and 64-bit code running on a 2.8 GHz Intel Xeon W3530 and a 3.6 GHz Intel Xeon W2123. Fixes #649
DRC 89ceac8c 2023-02-01T12:24:00 Decompress fuzzer: Fix uninitialized memory access (regression introduced by fc01f4673b71c0b833c59c21e8c4478a9c4bcf21) Oops. In the process of migrating the fuzzers to the TurboJPEG 3 API, I accidentally left out the code in decompress.cc that updates the width and height based on the scaling factor (but I apparently included that code in decompress_yuv.cc.) Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=55573
DRC dd89ce6c 2023-02-01T11:54:09 Build: Define THREAD_LOCAL even if !WITH_TURBOJPEG The SIMD dispatchers use thread-local storage now as well, because of f579cc11b33e5bfeb9931e37cc74b4a33c95d2e6.
DRC fd93d98a 2023-01-28T12:13:11 Fix i386 transform fuzzer build Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=55447
DRC 0205c6e0 2023-01-28T12:09:43 tjbench.c: Remove vestigial int overflow checks Since tj3Alloc() now accepts a size_t argument rather than an int argument, it is no longer necessary to check for signed integer overflow in the C version of TJBench.
DRC 6c5caf30 2023-01-27T18:30:11 Merge branch 'main' into dev
DRC 3b19db4e 2023-01-27T18:24:41 BUILDING.md: Specify install prefix for MinGW/Un*x The default install prefix when building under MinGW is chosen based on the needs of the official build system, which uses MSYS2 to generate Windows installer packages that install under c:\libjpeg-turbo-gcc[64]. However, attempting to configure the build with that install prefix on a Un*x machine causes a CMake error. Fixes #641
DRC 427c3045 2023-01-27T14:31:48 tjbench.c: Fix Windows build error (regression introduced by d7790789a6c3f0867175d781948e9d10fc55520d)
DRC fd8c4da0 2023-01-27T14:05:07 Bump revision to 2.1.90 to prepare for beta + acknowledge upcoming 2.1.5 release
DRC 9b3a8f36 2023-01-27T13:38:48 jcapimin.c: Revert changes made in fc01f467 Those changes worked around an innocuous UBSan warning that was exposed by the new TurboJPEG 3 transform fuzz target, due to the fact that tj3Transform() no longer rejects images with unknown subsampling configurations. That UBSan warning was a false positive, and attempting to fix it introduced a buffer overrun triggered by a malformed input image that causes jpeg_write_marker() to be called with datalen == 0. I suspect that the UBSan false positive was only reproducible on my local machine, but I guess we'll see. Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=55413
DRC d0015876 2023-01-27T13:08:04 Fix build if [CD]_LOSSLESS_SUPPORTED undefined (regression introduced by fc01f4673b71c0b833c59c21e8c4478a9c4bcf21)
DRC d7790789 2023-01-27T12:49:45 tjbench.c: Clean up THROW_TJ*() macro usage - Don't report which function was being called when a TurboJPEG error occurred, because the TurboJPEG error message already contains that information. - Use THROW_TJG() for functions that report errors globally instead of through an instance handle. - Use THROW_TJ() for the image I/O functions. - Formatting tweaks
DRC 54f571f8 2023-01-27T12:31:44 TurboJPEG: Clean up/repurpose THROWI() macro We already had a use case for two integer arguments, and the new use cases benefit from two integer arguments as well.
DRC 8c57aad0 2023-01-27T12:19:16 turbojpeg.c: Use THROWG() macro whenever possible
DRC b9404139 2023-01-27T07:20:10 TurboJPEG: Robustify JPEG header prefetching In decompression and transform functions, use the libjpeg API state rather than a TurboJPEG instance variable to determine whether jpeg_mem_src_tj() and jpeg_read_header() have already been called by a wrapper function.
DRC db9f297f 2023-01-27T07:10:49 ChangeLog.md: Document TurboJPEG 3 API overhaul
DRC 96bc40c1 2023-01-26T13:11:58 Implement arithmetic coding with 12-bit precision This actually works and apparently always has worked. It only failed because the libjpeg code, which did not originally support arithmetic coding, assumed that optimize_coding should always be TRUE for 12-bit data precision.
DRC fc01f467 2023-01-05T06:36:46 TurboJPEG 3 API overhaul (ChangeLog update forthcoming) - Prefix all function names with "tj3" and remove version suffixes from function names. (Future API overhauls will increment the prefix to "tj4", etc., thus retaining backward API/ABI compatibility without versioning each individual function.) - Replace stateless boolean flags (including TJ*FLAG_ARITHMETIC and TJ*FLAG_LOSSLESS, which were never released) with stateful integer parameters, the value of which persists between function calls. * Use parameters for the JPEG quality and subsampling as well, in order to eliminate the awkwardness of specifying function arguments that weren't relevant for lossless compression. * tj3DecompressHeader() now stores all relevant information about the JPEG image, including the width, height, subsampling type, entropy coding type, etc. in parameters rather than returning that information in its arguments. * TJ*FLAG_LIMITSCANS has been reimplemented as an integer parameter (TJ*PARAM_SCANLIMIT) that allows the number of scans to be specified. - Use the const keyword for all pointer arguments to unmodified buffers, as well as for both dimensions of 2D pointers. Addresses #395. - Use size_t rather than unsigned long to represent buffer sizes, since unsigned long is a 32-bit type on Windows. Addresses #24. - Return 0 from all buffer size functions if an error occurs, rather than awkwardly trying to return -1 in an unsigned data type. - Implement 12-bit and 16-bit data precision using dedicated compression, decompression, and image I/O functions/methods. * Suffix the names of all data-precision-specific functions with 8, 12, or 16. * Because the YUV functions are intended to be used for video, they are currently only implemented with 8-bit data precision, but they can be expanded to 12-bit data precision in the future, if necessary. * Extend TJUnitTest and TJBench to test 12-bit and 16-bit data precision, using a new -precision option. * Add appropriate regression tests for all of the above to the 'test' target. * Extend tjbenchtest to test 12-bit and 16-bit data precision, and add separate 'tjtest12' and 'tjtest16' targets. * BufferedImage I/O in the Java API is currently limited to 8-bit data precision, since the BufferedImage class does not straightforwardly support higher data precisions. * Extend the PPM reader to convert 12-bit and 16-bit PBMPLUS files to grayscale or CMYK pixels, as it already does for 8-bit files. - Properly accommodate lossless JPEG using dedicated parameters (TJ*PARAM_LOSSLESS, TJ*PARAM_LOSSLESSPSV, and TJ*PARAM_LOSSLESSPT), rather than using a flag and awkwardly repurposing the JPEG quality. Update TJBench to properly reflect whether a JPEG image is lossless. - Re-organize the TJBench usage screen. - Update the Java docs using Java 11, to improve the formatting and eliminate HTML frames. - Use the accurate integer DCT algorithm by default for both compression and decompression, since the "fast" algorithm is a legacy feature, it does not pass the ISO compliance tests, and it is not actually faster on modern x86 CPUs. * Remove the -accuratedct option from TJBench and TJExample. - Re-implement the 'tjtest' target using a CMake script that enables the appropriate tests, depending on the data precision and whether or not the Java API is part of the build. - Consolidate the C and Java versions of tjbenchtest into one script. - Consolidate the C and Java versions of tjexampletest into one script. - Combine all initialization functions into a single function (tj3Init()) that accepts an integer parameter specifying the subsystems to initialize. - Enable decompression scaling explicitly, using a new function/method (tj3SetScalingFactor()/TJDecompressor.setScalingFactor()), rather than implicitly using awkward "desired width"/"desired height" parameters. - Introduce a new macro/constant (TJUNSCALED/TJ.UNSCALED) that maps to a scaling factor of 1/1. - Implement partial image decompression, using a new function/method (tj3SetCroppingRegion()/TJDecompressor.setCroppingRegion()) and TJBench option (-crop). Extend tjbenchtest to test the new feature. Addresses #1. - Allow the JPEG colorspace to be specified explicitly when compressing, using a new parameter (TJ*PARAM_COLORSPACE). This allows JPEG images with the RGB and CMYK colorspaces to be created. - Remove the error/difference image feature from TJBench. Identical images to the ones that TJBench created can be generated using ImageMagick with 'magick composite <original_image> <output_image> -compose difference <diff_image>' - Handle JPEG images with unknown subsampling types. TJ*PARAM_SUBSAMP is set to TJ*SAMP_UNKNOWN (== -1) for such images, but they can still be decompressed fully into packed-pixel images or losslessly transformed (with the exception of lossless cropping.) They cannot be partially decompressed or decompressed into planar YUV images. Note also that TJBench, due to its lack of support for imperfect transforms, requires that the subsampling type be known when rotating, flipping, or transversely transposing an image. Addresses #436 - The Java version of TJBench now has identical functionality to the C version. This was accomplished by (somewhat hackishly) calling the TurboJPEG C image I/O functions through JNI and copying the pixels between the C heap and the Java heap. - Add parameters (TJ*PARAM_RESTARTROWS and TJ*PARAM_RESTARTBLOCKS) and a TJBench option (-restart) to allow the restart marker interval to be specified when compressing. Eliminate the undocumented TJ_RESTART environment variable. - Add a parameter (TJ*PARAM_OPTIMIZE), a transform option (TJ*OPT_OPTIMIZE), and a TJBench option (-optimize) to allow optimized baseline Huffman coding to be specified when compressing. Eliminate the undocumented TJ_OPTIMIZE environment variable. - Add parameters (TJ*PARAM_XDENSITY, TJ*PARAM_DENSITY, and TJ*DENSITYUNITS) to allow the pixel density to be specified when compressing or saving a Windows BMP image and to be queried when decompressing or loading a Windows BMP image. Addresses #77. - Refactor the fuzz targets to use the new API. * Extend decompression coverage to 12-bit and 16-bit data precision. * Replace the awkward cjpeg12 and cjpeg16 targets with proper TurboJPEG-based compress12, compress12-lossless, and compress16-lossless targets - Fix innocuous UBSan warnings uncovered by the new fuzzers. - Implement previous versions of the TurboJPEG API by wrapping the new functions (tested by running the 2.1.x versions of TJBench, via tjbenchtest, and TJUnitTest against the new implementation.) * Remove all JNI functions for deprecated Java methods and implement the deprecated methods using pure Java wrappers. It should be understood that backward API compatibility in Java applies only to the Java classes and that one cannot mix and match a JAR file from one version of libjpeg-turbo with a JNI library from another version. - tj3Destroy() now silently accepts a NULL handle. - tj3Alloc() and tj3Free() now return/accept void pointers, as malloc() and free() do. - The image I/O functions now accept a TurboJPEG instance handle, which is used to transmit/receive parameters and to receive error information. Closes #517
DRC 1a1ea4ee 2023-01-25T12:28:42 Merge branch 'main' into dev
DRC 27f4ff80 2023-01-25T11:09:36 Java: Guard against int overflow in size methods Because Java array sizes are ints, the various size methods in the TJ class have int return values. Thus, we have to guard against signed int overflow at the JNI level, because the C functions can return sizes greater than INT_MAX. This also adds a test for TJ.planeWidth() and TJ.planeHeight(), in order to validate 8a1526a442a9eca8813fcf878fa5cfdd4260be83 in Java.
DRC 1485beaa 2023-01-25T12:13:21 turbojpeg.c: Fix UBSan warning (introduced by previous commit)
DRC 8a1526a4 2023-01-25T09:52:06 tjPlane*(): Guard against int overflow tjPlaneWidth() and tjPlaneHeight() could overflow a signed int and return a negative value if passed a width/height argument of INT_MAX and a subsampling type for which the MCU block size is larger than 8x8.
DRC 52659f4f 2023-01-23T09:55:13 Merge branch 'main' into dev
DRC edbb7e6d 2023-01-23T09:32:57 Java doc: TJ.pixelSize --> TJ.getPixelSize() TJ.pixelSize isn't actually a thing. Oops.
DRC af1b4c8d 2023-01-21T18:31:20 TJBench: Unset TJ*OPT_CROP when disabling tiling Otherwise, if the input image is a JPEG image, then an unnecessary lossless transformation will be performed.
DRC 2aac5458 2023-01-20T16:02:30 TJExample: Remove "underlying codec" references (Oversight from 9a146f0f23b01869e1bf7c478e12b43f83d59c32)
DRC 7ab6222c 2023-01-20T14:09:25 Merge branch 'main' into dev
DRC 0738305e 2023-01-20T13:41:25 GitHub: Update to actions/checkout@v3 ... to silence deprecation warning regarding Node.js 12 actions.
DRC 98a64558 2023-01-20T13:14:11 TJBench: Set TJ*OPT_PROGRESSIVE with -progressive The documented behavior of the -progressive option is to use progressive entropy coding in JPEG images generated by compression and transform operations. However, setting TJFLAG_PROGRESSIVE was insufficient to accomplish that, because TJBench doesn't enable lossless transformation if xformOpt == 0.
DRC b99e7590 2023-01-20T10:50:21 TJBench/Java: Fix parsing of quality ranges
DRC 28c2e607 2023-01-18T15:31:04 TJBench: Strictly check all non-boolean arguments + document that the value of -yuvpad must be a power of 2 (refer to d2608583955f060ae7efa950a94d921fdd387d58)
DRC fb15efe9 2023-01-18T06:44:46 TurboJPEG: More documentation improvements - TJBench/TJUnitTest: Wordsmith command-line output - Java: "decompress operations"="decompression operations" - tjLoadImage(): Error message tweak - Don't mention compression performance in the description of TJXOPT_PROGRESSIVE/TJTransform.OPT_PROGRESSIVE, because the image has already been compressed at that point. (Oversights from 9a146f0f23b01869e1bf7c478e12b43f83d59c32)
DRC 6a060d8c 2023-01-17T18:32:15 TJCompressor.java: (C) header formatting tweak (apparently borked by one of the previous merge commits)
DRC c7c02d92 2023-01-17T18:31:31 Merge branch 'main' into dev
DRC 7ed186ed 2023-01-17T18:18:27 TJDecompressor.java: Exception message tweak NO_ASSOC_ERROR is specific to JPEG source images, but the decompress() methods can handle YUV source images as well.
DRC 08cbc233 2023-01-17T11:04:38 12-bit: Set alpha channel to 4095 rather than 255
DRC 155a8b03 2023-01-16T17:02:01 Merge branch 'main' into dev
DRC 0c0df2d0 2023-01-16T16:52:46 TJDecompressor.java: "YUV" = "planar YUV" (Oversight from 9a146f0f23b01869e1bf7c478e12b43f83d59c32)
DRC 22a66368 2023-01-16T15:32:49 Java: Don't allow int overflow in buf size methods This is similar to the fix that 2a9e3bd7430cfda1bc812d139e0609c6aca0b884 applied to the C API. We have to apply it separately at the JNI level because the Java API always stores buffer sizes in 32-bit integers, and the C buffer size functions could overflow an int when using 64-bit code. (NOTE: The Java API stores buffer sizes in 32-bit integers because Java itself always uses 32-bit integers for array sizes.) Since Java don't allow no buffer overruns 'round here, this commit doesn't change the ultimate outcome. It just makes the inevitable exception easier to diagnose.
DRC d859232d 2023-01-14T18:27:37 TurboJPEG: Use 4:4:4 for lossless JPEG buf calcs
DRC d4589f4f 2023-01-14T18:07:53 Merge branch 'main' into dev
DRC 94a2b953 2023-01-11T15:01:35 tjDecompressToYUV2: Use scaled dims for plane calc The documented behavior of the function is to use decompression scaling to generate the largest possible image that will fit within the desired image dimensions. Thus, if the desired image dimensions are larger than the scaled image dimensions, then tjDecompressToYUV2() should use the scaled image dimensions when computing the plane pointers and strides to pass to tjDecompressToYUVPlanes(). Note that this bug was not previously detected, because tjunittest and tjbench always passed the scaled image dimensions to tjDecompressToYUV2().
DRC 9a146f0f 2023-01-06T10:29:10 TurboJPEG: Numerous documentation improvements - Wordsmithing, formatting, and grammar tweaks - Various clarifications and corrections, including specifying whether a particular buffer or image is used as a source or destination - Accommodate/mention features that were introduced since the API documentation was created. - For clarity, use "packed-pixel" to describe uncompressed source/destination images that are not planar YUV. - Use "row" rather than "line" to refer to a single horizontal group of pixels or component values, for consistency with the libjpeg API documentation. (libjpeg also uses "scanline", which is a more archaic term.) - Use "alignment" rather than "padding" to refer to the number of bytes by which a row's width is evenly divisible. This consistifies the documention of the YUV functions and tjLoadImage(). ("Padding" typically refers to the number of bytes added to each row, which is not the same thing.) - Remove all references to "the underlying codec." Although the TurboJPEG API originated as a cross-platform wrapper for the Intel Integrated Performance Primitives, Sun mediaLib, QuickTime, and libjpeg, none of those TurboJPEG implementations has been maintained since 2009. Nothing would prevent someone from implementing the TurboJPEG API without libjpeg-turbo, but such an implementation would not necessarily have an "underlying codec." (It could be fully self-contained.) - Use "destination image" rather than "output image", for consistency, or describe the type of image that will be output. - Avoid the term "image buffer" and instead use "byte buffer" to refer to buffers that will hold JPEG images, or describe the type of image that will be contained in the buffer. (The Java documentation doesn't use "byte buffer", because the buffer arrays literally have "byte" in front of them, and since Java doesn't have pointers, it is not possible for mere mortals to store any other type of data in those arrays.) - C: Use "unified" to describe YUV images stored in a single buffer, for consistency with the Java documentation. - Use "planar YUV" rather than "YUV planar". Is is our convention to describe images using {component layout} {colorspace/pixel format} {image function}, e.g. "packed-pixel RGB source image" or "planar YUV destination image." - C: Document the TurboJPEG API version in which a particular function or macro was introduced, and reorder the backward compatibility function stubs in turbojpeg.h alphabetically by API version. - C: Use Markdown rather than HTML tags, where possible, in the Doxygen comments.
DRC b03ee8b8 2023-01-05T11:17:40 TurboJPEG: Don't use backward compatibility macros Macros from older versions of the TurboJPEG API are supported but not documented, so using the current version of those macros makes the code more readable.
DRC d2608583 2023-01-05T10:51:12 TurboJPEG: Ensure 'pad' arg is a power of 2 Because the PAD() macro can only handle powers of 2, this is a necessary restriction (and a documented one, except in the case of tjCompressFromYUV()-- oops.) Failing to check the 'pad' argument caused tjBufSizeYUV2() to return bogus results if 'pad' was less than 1 or otherwise not a power of 2. tjEncodeYUV3() and tjDecodeYUV() effectively treated a 'pad' value of 0 as unpadded, but that was subtle and undocumented behavior. tjCompressFromYUV() did not check whether 'pad' was a power of 2, so the strides passed to tjCompressFromYUVPlanes() would have been incorrect if 'pad' was not a power of 2. That would not have caused tjCompressFromYUV() to overrun the source buffer, as long as the calling application allocated the buffer based on the return value of tjBufSizeYUV2() (which computes the strides in the same manner as tjCompressFromYUV().) However, if the calling application attempted to initialize the source buffer using correctly-computed strides, then it could have overrun its own buffer in certain cases or produced incorrect JPEG images in others. Realistically, there is no reason why an application would want to pass a non-power-of-2 'pad' value to a TurboJPEG API function, so this commit is about user-proofing the API rather than fixing any known issue.
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