The idea is to use ffmath.h for internal implementations of math functions.
Currently, it is used for variants of libm functions, but is by no means
limited to such things.
Note that this is not exported; use lavu/mathematics for such purposes.
Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanag@gmail.com>
This is ~2x faster for y not an integer on Haswell+GCC, and should
generally be faster due to the fact that anyway powf essentially does
this under the hood. Made an inline function in lavu/internal.h for this
purpose.
Note that there are some accuracy differences, that should generally be
negligible. In particular, FATE still passes on this platform.
Results in ~ 7% speedup in aac encoding with -march=native, Haswell+GCC.
before:
ffmpeg -i sin.flac -acodec aac -y sin_new.aac 6.05s user 0.06s system 104% cpu 5.821 total
after:
ffmpeg -i sin.flac -acodec aac -y sin_new.aac 5.67s user 0.03s system 105% cpu 5.416 total
This is also faster than an alternative approach that pulls in powf, gets rid of
the crufty NaN checks and other special cases, exploits knowledge about the intervals, etc.
This of course does not exclude smarter approaches; just suggests that
there would need to be significant work on this front of lower utility than
searches for hotspots elsewhere.
Reviewed-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanag@gmail.com>
Fast, reasonably accurate 10^x. Alternative of detection of libm exp10 at configure
time is not worth the trouble, since it is anyway not POSIX or ISO C,
and currently only the GNU libm has it. Furthermore, GNU libm's variant
is ~ 2x slower, and is ironically not correctly rounded (2 ulp off) to justify all
that slowdown.
Reviewed-by: James Almer <jamrial@gmail.com>
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Include macros.h explicitly in common.h so that external code using
FFALIGN does not break. It was already implicitly included through
version.h. Include macros.h in lls.h and internal.h for FFALIGN.
lls.h was including common.h only for FFALIGN and internal.h was
missing the include for FFALIGN. `make checkheaders` did not catch it
because it's an internal header.
The function is renamed to ff_rint64_clip()
This should avoid build failures on VS2012
Feel free to changes this to a different solution
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The open syscall can obviously fail, and its return code needs to be
checked.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
FATE refs changed to accomodate for the new default behavior of the function.
Numbers are now interpreted as a channel layout, instead of a number of channels.
The table is used in libavutil/eval.c.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
When compiling libavutil/internal.h as C++11, clang warns that a space
is required between a string literal and an identifier. Put spaces
in concatenations of string literals and EXTERN_PREFIX.
Signed-off-by: Chris Watkins <watk@chromium.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The C runtime C99 compatibility had been improved a lot and it now
rejects some of the compatibility defines provided for the older
versions.
Many thanks to Ray for the time spent testing.
Bug-Id: 864
CC: libav-stable@libav.org
Without this a developer would have to add a include every time he
wants to benchmark some code, this is a moderate inconvenience.
This reverts the specific hunk from fb0c9d41d685abb58575c5482ca33b8cd457c5ec
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
The new syntax is preferred since it allows backward syntax compatibility
with libswr when switching to the new option handling code with
AV_OPT_TYPE_CHANNEL_LAYOUT.
With the new parser the string:
1234
is interpreted as a channel layout mask, rather than as a number of
channels, and thus it's compatible with the current way to set a channel
layout as an integer (e.g. for the icl and ocl options) making use of
integer option values.
ff_get_channel_layout() with compat=0 will be used in the
AV_OPT_TYPE_CHANNEL handler code.
The user is encouraged to switch to the new forward compatible syntax,
which requires to put a trailing "c" when specifying a layout as a number
of channels.
Prior to this on msvc/icl there was no handling of deprecated functions
and the deprecated warning was disabled.
After enabling there are a number of warnings relating to the CRT and
the use of the non-secure versions of several functions. Defining
_CRT_SECURE_NO_WARNINGS silences these warnings.
Signed-off-by: Martin Storsjö <martin@martin.st>
Add one copy of the function into each of the libraries, similarly
to what we do for log2_tab. When using static libs, only one
copy of the file_open.o object file gets included, while when
using shared libraries, each of them get a copy of its own.
This fixes DLL builds with a statically linked C runtime, where
each DLL effectively has got its own instance of the C runtime,
where file descriptors can't be shared across runtimes.
On systems not using msvcrt, the function is not duplicated.
Signed-off-by: Martin Storsjö <martin@martin.st>
This used to only be necessary in static builds (when using the
dynamically linked C runtime), since the _imp prefixed symbols do
exist when linking to the actual DLL. When building testprogs,
however, the current library (e.g. libavutil for some of the testprogs)
is linked statically.
This fixes make fate on DLL builds when using the dynamically
linked C runtime.
Signed-off-by: Martin Storsjö <martin@martin.st>
This provides a fallback when building with Yasm enabled, but neither
inline assembly, nor the _mm_empty intrinsic are available or enabled.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Preventing the use of discouraged or 'insecure' external functions
through defines in an internal header is not a good solution. The
header is not guaranteed to be included universally which makes
overlooking bad use of said functions during review more likely.
There are cases were those functions either are the most straight
forward solution or even have to be used. Using malloc or free is
required if the allocation or release is done by other libraries.
This requires the makedef perl script by Derek, from the
c89-to-c99 repo. That scripts produces a .def file, listing
the symbols to be exported, based on the gcc version scripts
and the built object files.
To properly load non-function symbols from DLL files, the
data symbol declarations need to have the attribute
__declspec(dllimport) when building the calling code. (On mingw,
the linker can fix this up automatically, which is why it has not
been an issue so far. If this attribute is omitted, linking
actually succeeds, but reads from the table will not produce the
desired results at runtime.)
MSVC seems to manage to link DLLs (and run properly) even if
this attribute is present while building the library itself
(which normally isn't recommended) - other object files in the
same library manage to link to the symbol (with a small warning
at link time, like "warning LNK4049: locally defined symbol
_avpriv_mpa_bitrate_tab imported" - it doesn't seem to be possible
to squelch this warning), and the definition of the tables
themselves produce a warning that can be squelched ("warning C4273:
'avpriv_mpa_bitrate_tab' : inconsistent dll linkage, see previous
definition of 'avpriv_mpa_bitrate_tab').
In this setup, mingw isn't able to link object files that refer to
data symbols with __declspec(dllimport) without those symbols
actually being linked via a DLL (linking avcodec.dll ends up with
errors like "undefined reference to `__imp__avpriv_mpa_freq_tab'").
The dllimport declspec isn't needed at all in mingw, so we simply
choose not to declare it for other compilers than MSVC that requires
it. (If ICL support later requires it, the condition can be extended
later to include both of them.)
This also implies that code that is built to link to a certain
library as a DLL can't link to the same library as a static library.
Therefore, we only allow building either static or shared but not
both at the same time. (That is, static libraries as such can be,
and actually are, built - this is used for linking the test tools to
internal symbols in the libraries - but e.g. libavformat built to
link to libavcodec as a DLL cannot link statically to libavcodec.)
Also, linking to DLLs is slightly different from linking to shared
libraries on other platforms. DLLs use a thing called import
libraries, which is basically a stub library allowing the linker
to know which symbols exist in the DLL and what name the DLL will
have at runtime.
In mingw/gcc, the import library is usually named libfoo.dll.a,
which goes next to a static library named libfoo.a. This allows
gcc to pick the dynamic one, if available, from the normal -lfoo
switches, just as it does for libfoo.a vs libfoo.so on Unix. On
MSVC however, you need to literally specify the name of the import
library instead of the static library.
Signed-off-by: Martin Storsjö <martin@martin.st>
There are cases where strncpy() does exactly what is required.
A blanket ban forces more convoluted solutions to be used in those
cases and has been a cause of bugs.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Marton Balint
Ganesh Ajjanagadde
Michael Niedermayer
Ganesh Ajjanagadde
Janne Grunau
Timothy Gu
Hendrik Leppkes
Ronald S. Bultje
Andreas Cadhalpun
Chris Watkins
Luca Barbato
Michael Niedermayer
Peter Tissen
wm4
Vittorio Giovara
Gabriel Dume
Diego Biurrun
James Almer
Carl Eugen Hoyos
Stefano Sabatini
Alex Smith
Reimar Döffinger
Martin Storsjö
Rémi Denis-Courmont
Paul B Mahol
Mans Rullgard