Les articles publiés sur le site
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9 août 2014, par Erik de Castro Lopo
libFLAC/lpc_intrin_sse.c : New SSE code to calculate autocorrelation.
Accelerate FLAC__lpc_compute_autocorrelation_intrin_sse_lag_NN routines for
AMD and newer Intel CPUs (means Core i aka Nehalem and newer). Unfortunately
it's slower on older Intel CPUs.
According to tests at HA:
<http://www.hydrogenaud.io/forums/index.php?s=&showtopic=101082&view=findpost&p=870753>
CPU flac -5 flac -8
Athlon XP +5 % +2.4 %
Athlon 64 X2 +9 % +4 %
Core i +7 % +1 % ... +2.7 %
Core 2 ? -3.5 %
According to Steam HW survey <http://store.steampowered.com/hwsurvey/>
69% of Steam users have SSE4.2 which means that the new code is faster for
them. There are also AMD users that don't have SSE4.2, so 75% of Steam users
should benefit from this patch.
Patch-from: lvqcl <lvqcl.mail@gmail.com>
- [DH] src/libFLAC/lpc_intrin_sse.c
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1er août 2014, par Martijn van Beurden
Various documentation fixes, merge with website
The html documentation was diff'ed to the current website pages
and all difference were merged into the page they weren't yet
incorporated. This includes lots of small fixes and
improvements.
Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
- [DH] doc/html/Makefile.am
- [DH] doc/html/changelog.html
- [DH] doc/html/documentation.html
- [DH] doc/html/documentation_bugs.html
- [DH] doc/html/documentation_tools.html
- [DH] doc/html/documentation_tools_flac.html
- [DH] doc/html/documentation_tools_plugins.html
- [DH] doc/html/faq.html
- [DH] doc/html/format.html
- [DH] doc/html/id.html
- [DH] doc/html/license.html
- [DH] doc/html/ogg_mapping.html
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28 juillet 2014, par Martijn van Beurden
Fix bug when using -p switch during compression
When using the -p switch during encoding, the encoder should try
different qlp predictor precision steps. However, some faulty code
was too severely restricting the possible steps. This patch lifts
the restriction to match a restriction coded a little further in
the process. This doesn't make using -p worth your while, but at
least it doesn't create larger files now
Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
- [DH] src/libFLAC/stream_encoder.c
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28 juillet 2014, par Erik de Castro Lopo
libFLAC/cpu.c : Simplify OS SSE support detection.
Simplify the code that tries to detect whether OS supports SSE instructions.
a) Linux: "old" vs "new" sigaction
OBSOLETE_SIGCONTEXT_FLAVOR was disabled in Mar 2007 in commit 1ca3a445f.
According to <http://unixhelp.ed.ac.uk/CGI/man-cgi?sigaction>: "Support for
SA_SIGINFO was added in Linux 2.2" (released in Jan 1999). If noone wants to
use FLAC with Linux kernel 2.0 then it's safe to delete this code.
b) MSVC: try/catch vs. sigill_handler
TRY_CATCH_FLAVOR was enabled in Jan 2009 in commit a832ef32. According to the
comment in cpu.c, "sigill_handler flavor resulted in several crash reports on
win32". Also this sigill_handler flavor is not thread-safe.
c) MinGW: fxsave/fxrestore vs. sigill_handler
The code was added Mar 2014 in commit 99d5154f. It's better to use FXSR flavor
instead of sigill_handler flavor. The reasons are the same as for MSVC.
Patch-from: lvqcl <lvqcl.mail@gmail.com>
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28 juillet 2014, par Erik de Castro Lopo
libFLAC : SSE optimisations.
Add new function:
FLAC__lpc_compute_residual_from_qlp_coefficients_intrin_sse41()
and rewrite function:
FLAC__lpc_compute_residual_from_qlp_coefficients_16_intrin_sse2()
Testing shows noticeable speed increase on Intel Core i3/5/7 (up to 30%
for -8 mode), AMD Athlon64, Phenom, Bulldozer/Piledriver, but no increase
or even very small speed decrease (~2% for -8 mode) on Intel Core2.
Patch-from: lvqcl <lvqcl.mail@gmail.com>
- [DH] src/libFLAC/include/private/lpc.h
- [DH] src/libFLAC/lpc_intrin_sse2.c
- [DH] src/libFLAC/lpc_intrin_sse41.c
- [DH] src/libFLAC/stream_encoder.c
