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] 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.
+[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 will blindly reject any library that is not versioned,
+so this was an attempt to make them happy.
+
+[3] Extended the TurboJPEG Java API so that it can be used to decompress a
+JPEG image into an arbitrary position in a large output buffer.
+
+
+1.2.1
+=====
-[3] Creating or decoding a JPEG file that uses the RGB colorspace should now
+[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.
-[4] When libjpeg-turbo was built without SIMD support and merged (non-fancy)
+[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.
-[5] 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 will blindly reject any library that is not versioned,
-so this was an attempt to make them happy.
-
-[6] Fixed a bug whereby the libjpeg-turbo SSE2 SIMD code would not preserve the
+[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.
-[7] Fixed a regression caused by 1.2.0[6] in which decompressing corrupt JPEG
+[4] Fixed a regression 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.
-[8] Extended the TurboJPEG Java API so that it can be used to decompress a
-JPEG image into an arbitrary position in a large output buffer.
-
-[9] Worked around a severe performance issue with "Bobcat" (AMD Embedded APU)
+[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.
-[10] Fixed a regression caused by 1.2.0[2] whereby, on Linux/x86 platforms,
+[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,
decompressing a 4:2:0 or 4:2:2 JPEG image 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
projects / libjpeg-turbo / commitdiff