* commit '4822ee3ca620a92cd2b0a9a03ea9e34288192c79':
configure: Detect AIX ar command instead of hardcoding it in the OS section
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '7ef760d95c73dfee021b8fdee04f65126eb7edd1':
configure: generate full msvc debug symbols when linking in debug mode
Merged-by: Michael Niedermayer <michaelni@gmx.at>
There is no record of this ever being used at all, anywhere,
since the feature was added in 2effd27446.
This gets rid of extra linker tricks just to support a feature
that isn't used, simplifying portability to other platforms.
Signed-off-by: Martin Storsjö <martin@martin.st>
The avresample maintainers decided not to support old versions of yasm.
Supporting old yasm in FFmpeg was no big effort in the last months,
so keep it for the time being.
* commit 'ef5b70affc6376bfeadd1ff649b79bad9a124fa8':
configure: Check for support for labels in the inline assembly
The timer code is not placed under ifdef as ours does not use labels
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Use this for enabling the ppc timer.h implementation only on
assemblers that support labels in the inline assembly.
Signed-off-by: Martin Storsjö <martin@martin.st>
"Fork" is an ambiguous term, since there may be more than one fork, also
"fork" could be confused with the corresponding function. Also it seems
important to point the name of the referenced fork in the symbol.
Note: the old --enable-incompatible-fork-abi command is retained for
compatibility, although it should be considered deprecated.
Replace the inline awk script with a Perl script which tracks the
dependencies recursively.
This allows to correctly track dependencies for files including files
with a second level include (for example: ffmpeg-devices.texi ->
devices.texi -> outdevs.texi).
This also adds a dependency on perl for computing the dependencies, which
should not be a problem since perl is already required all the way for
building documentation.
* commit '9f4a16c52ea8f2383244587ea4cb534fe7f6da49':
configure: Do not explicitly set Oy for msvc/icl
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Because O1 or O2 are required to build libav with msvc/icl, this must be
explicitly set instead of just omitting Oy.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
It is implied by O1 or O2, both of which are required to build libav
with msvc/icl. Silences warnings when targeting x64 with icl.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
* commit '6dc6598692da3b0ebda2d768681786343f26a4f4':
configure: Simplify an expression with enabled_all.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
As of r5799 in MinGW-w64's trunk, which is he upcoming major version 3,
the POSIX-compliant vsnprintf implementation is disabled by default.
Enable it for this version. Keep using out own implementation for
prior versions, because it is broken in them.
Relevant Reference Thread: http://article.gmane.org/gmane.comp.gnu.mingw.w64.general/7133
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
frei0r license is GPL.
Based on a patch by Timothy Gu <timothygu99@gmail.com>.
See thread:
Subject: [FFmpeg-devel] [PATCH 1/2] LICENSE: Complete GPL'd external libraries list
Date: Thu, 6 Jun 2013 18:55:30 -0700
* commit '3fd0d166aa240ef547482d1af397c4a653031c2d':
configure: Don't explicitly disable PIC for windows targets
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '2aa3325454545b63cd63e3d5884f8558790d51df':
configure: arm: Don't try to enable pic for shared libraries on win32
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This avoids warnings about this option not having any effect on
this platform.
We still want to enable the pic configure item for these platforms
(if detected via the compiler builtin define __PIC__) to get proper
inline assembly workarounds.
Signed-off-by: Martin Storsjö <martin@martin.st>
This reverts e08c946c6 and 05165c2f7a. The actual intention of
e08c946c6 was to fix shared library builds for arm/win32, which
can also be accomplished in other ways.
Disabling pic on those platforms broke inline assembly on cygwin/64
(since some inline assembly requires knowing whether we are building
as PIC or not), and might also break inline assembly on other
compilers on windows.
As a side-effect, this unfortunately brings back all the warnings
about PIC not having any effect on that platform.
Signed-off-by: Martin Storsjö <martin@martin.st>
The object file format doesn't support PIC loads in ARM assembly,
there are no relocation types in PE/COFF that correspond to
BFD_RELOC_32_PCREL (R_ARM_REL32 in ELF).
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit '14fb9d3d8ccf5f50180aabdb1afe8b570fea3d28':
configure: Separate commonalities in msvc and icl flags
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Allows for easier handling of flags that may be specific to icl or msvc.
Furthermore, simplify the handling of warnings and remarks thanks to
icl's support of -Wall on Windows.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Based on the work of Jeff Moguillansky <Jeff.Moguillansky@am.sony.com>.
See thread:
Subject: [FFmpeg-devel] x11 output device for libavdevice
Date: Wed, 10 Apr 2013 23:10:47 +0000
* commit '78f75b6fa421dd39a715588e9487579f1ce5bada':
wavpack: extract sample rate from the bitstream
configure: support gcc-4.8 instrumentation
Conflicts:
libavcodec/wavpack.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The modern MSVC for ARM always builds for thumb, and it can't be
disabled.
Also just use the default arch instead of trying to map the -march
parameter to MSVC's -arch parameter (which only takes the values
ARMv7VE and VFPv4).
Signed-off-by: Martin Storsjö <martin@martin.st>
* qatar/master:
smacker: add a clarification notice about audio decoding
configure: make jack depend on pthreads
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '9495cd170b5786c3518419e873d94eb5e7ada11a':
configure: Fix check_exec_crash for ICL support
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Initial support for the ICL compiler on windows. Requires a new
c99wrap with ICL support (1.0.2+).
Currently not much different speed wise compared to msvc. In the
future with a few changes it can be made to support the inline asm.
This would be the primary reason for using it.
Passed all fate tests, versions tested:
13.1.1.171 (2013 Update 3) x86 and x64
12.1.5.344 (2011 Update 11) x86 and x64
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Change the check_exec_crash test to use a function pointer instead of
simply calling the function. The EBP availability test will crash when
compiled with ICL likely due to compiler optimization shenanigans.
Originally the check_exec_crash code was moved out of main to fix a
problem with gcc's treatment of non-leaf main on x86_32. Libav already
moved the code out of main but the addition of the function pointer will
prevent any inlining which fixes the remaining problem.
A function pointer is used since it is compiler agnostic (as opposed to
say __attribute__ ((noinline)) which would only work with gcc compatible
compilers).
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
* commit '0b6899f154347cdd0aa66c5ec16ed9c65871766f':
configure: msvc: Set the target windows version to XP if no target is set
Merged-by: Michael Niedermayer <michaelni@gmx.at>
MSVC 2010 (or more precisely, Windows SDK 7.0 which comes with MSVC
2010) sets _WIN32_WINNT to the constant for Windows 7 if nothing is
set. This could lead to the libav configure script detecting and
using functions only present in Windows 7 or newer, which in most
cases isn't desired. If the caller explicitly wants this, the caller
can add the _WIN32_WINNT define via --extra-cflags, setting the desired
version.
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit '8e673efc6f5b7a095557664660305148f2788d30':
prores: update FATE test to account for alpha plane present in the test sample
configure: Add basic valgrind-massif support
Conflicts:
tests/fate/prores.mak
tests/ref/fate/prores-alpha
Merged-by: Michael Niedermayer <michaelni@gmx.at>
With the parameter --toolchain valgrind-massif, the configure
script sets reasonable defaults that can be overridden as explained
in the documentation.
* qatar/master:
configure: Use linker hardening flags on mingw
vc1: Make INIT_LUT() self contained
vc1: Simplify code by using INIT_LUT()
vc1: Move INIT_LUT() further up to allow using it in more places
vc1dec: Remove some now unused variables
vc1dec: Do not allow field_mode to change after the first header
vc1, mss2: Check for any negative return value from ff_vc1_parse_frame_header
vc1dec: Fix current ptr selection in vc1_mc_4mv_chroma()
vc1dec: Factorize picture pointer selection in vc1_mc_4mv_chroma()
vc1dec: Factorize picture pointer selection code
vc1dec: Factorize srcU/V offseting
vc1dec: Fix tff == 0 handling in init_block_index()
vc1dec: Update destination pointers in context for fields
Conflicts:
libavcodec/vc1.c
libavcodec/vc1dec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This makes it consistent with the msvc builds which automatically set
the DEP and ASLR flags by default. There really is no good reason why
they shouldn't be set.
The fact that binutils does not set them on by default boggles the mind.
Signed-off-by: Martin Storsjö <martin@martin.st>
If this is explicitly disabled for win32/mingw, it should also
be disabled for cygwin, for consistency and for the same reasons
as for win32/mingw.
Signed-off-by: Martin Storsjö <martin@martin.st>
These platforms do not have any notion of PIC. On some compilers,
enabling pic produces a number of warnings.
This avoids trying to produce PIC loads in the ARM assembly - there
are no relocation types in PE/COFF that correspond to
BFD_RELOC_32_PCREL (R_ARM_REL32 in ELF).
As a side-effect, this avoids enabling PIC on mingw64, getting rid
of the warnings about PIC not having any effect on that platform.
Signed-off-by: Martin Storsjö <martin@martin.st>
This allows it to be overridden, either by the user on the command
line, or by other sections of the configure script.
Signed-off-by: Martin Storsjö <martin@martin.st>
When targeting the "windows store application" (metro) API subset
(or the windows phone API subset), the getenv function isn't
available. If it is unavailable, just define getenv to NULL.
The check uses check_func_headers, since the function actually
might exist in the libraries, but is hidden in the headers.
The fallback is in config.h since msvc can't do -D defines with
parameters on the command line, and it's used both within the
libraries and the frontend applications (so a libavutil internal
header wouldn't be enough).
Signed-off-by: Martin Storsjö <martin@martin.st>
With the parameter --valgrind-memcheck, the configure script sets
reasonable defaults that can be overridden as explained in the
documentation.
The idea of using set_defaults is from Luca Barbato.
* qatar/master:
compat: msvc: Make sure the object files are included when linking statically
id3v2: check for end of file while unescaping tags
Conflicts:
configure
libavformat/id3v2.c
Note, ffmpeg is not affected by the out of buffer write bug
Merged-by: Michael Niedermayer <michaelni@gmx.at>
If building libav with -MD in the cflags (for making the MSVC compiler
generate code for using a dynamically linked libc), the system headers
that declare strtod, snprintf and vsnprintf declare the functions as
imported from a DLL. To hook up wrappers of our own for these functions,
the function names are defined to avpriv_*, so that the calling code
within libav calls the wrappers instead. Since these functions
are declared to be imported from DLLs, the calling code expects to
load them from DLL import function pointers (creating references to
_imp__avpriv_strtod instead of directly to avpriv_strtod). If the
libav libraries are not built as DLLs, no such function pointers (as
the calling code expects) are created.
The linker can fix this up automatically in some cases (producing
warnings LNK4217 and LNK4049), if the object files are already
included. By telling the linker to try to include those symbols
(without the _imp prefix as the calling code ends up using),
we get the object files included, so that the linker can do the
automatic fixup. This is done via config.h, so that all (or at least
most) of the object files in our libraries force including the compat
files, to make sure they are included regardless of what files from our
static libraries actually are included.
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit 'ffb068ce8e99df121d18a5b9b1d820f3ea8697fb':
configure: Don't do enable_deep_weak on disabled variables
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '4d810ad2e943a59658ddf00a397121c2b62f7157':
configure: Use a different variable name in push/popvar
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This avoids cases where configure tries to weakly enable an item
which actually is disabled, ending up still enabling dependencies
of the item which itself is only enabled weakly.
More concretely, the h264 decoder suggests error resilience, which
is then enabled weakly (unless manually disabled). Previously,
dsputil, which is a dependency of error resilience, was enabled
even if error resilience wasn't enabled in the end.
Signed-off-by: Martin Storsjö <martin@martin.st>
The variable name 'var' is commonly used to iterate through arguments
in other functions. When the pushvar function internally uses the
variable 'var', it makes pushing/popping the variable 'var' not
work as intended.
Signed-off-by: Martin Storsjö <martin@martin.st>
vidstabdetect and vidstabtransform common functions for interfacing
vid.stab are in libavfilter/vidstabutils.c
Signed-off-by: Georg Martius <martius@mis.mpg.de>
* commit '28bc406c84b04a5f1458b90ff52ddbec73e46202':
mjpeg: Use hpeldsp instead of dsputil for half-pel functions
svq1enc: Use hpeldsp instead of dsputil for half-pel functions
Conflicts:
configure
libavcodec/mjpegdec.c
libavcodec/svq1enc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '2f6bc5f7c193477c2ebc0acce8f2d5551445e129':
svq3: Use hpeldsp instead of dsputil for half-pel functions
mpegvideo: Use hpeldsp instead of dsputil for half-pel functions
svq1: Use hpeldsp instead of dsputil for half-pel functions
mimic: Use hpeldsp instead of dsputil for half-pel functions
Conflicts:
configure
libavcodec/motion_est.c
libavcodec/mpegvideo.c
libavcodec/mpegvideo.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The next commit will introduce a proper decimation filter to be used
along with the field matching filter. To avoid confusion with this
filter which has currently a very limited usage (and will not work
properly with the fieldmatching filter), the new decimation filter will
take the decimate name, and this filter is renamed to mpdecimate.
* qatar/master:
FATE: add a test for the interlace filter
lavfi: new interlace filter
Conflicts:
Changelog
configure
doc/filters.texi
libavfilter/Makefile
libavfilter/allfilters.c
tests/fate/filter.mak
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The gcov/lcov are a common toolchain for visualizing code coverage with
the GNU/Toolchain. The documentation and implementation of this
integration was heavily inspired from the blog entry by Mike Melanson:
http://multimedia.cx/eggs/using-lcov-with-ffmpeg/
* commit 'fc43c19a567aa945398dccb491d972c11ec2a065':
matroska: Update the available size after lace parsing
clang: use -fsantize=address and -fsanitize=thread
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '817dff578f13ce97576c609ab141508b9dc782e9':
configure: Check for the atomic.h functions used in the suncc atomics header
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The "suncc" atomics implementation uses a suncc specific memory
barrier, but also relies on a few atomic functions from atomic.h,
that are not suncc specific but specific to solaris. This made
the current implementation fail on suncc on linux.
* commit 'e9cc98839574c7e8d546e890ebbf57d1766e5d8a':
win32: Allow other programs to open the same files
configure: Add error_resilience as dependency to the eatqi decoder
Conflicts:
configure
libavformat/os_support.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'd767e2f969933b4e450ed4e69ea2bf8ca864838c':
configure: fix dependencies of XvMC and old vdpau mpeg2 decoders
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This makes standalone compilation of the eatqi decoder
succeed. The dependency comes from the shared mpeg12dec.o file.
Signed-off-by: Martin Storsjö <martin@martin.st>
* qatar/master:
h264: Make it possible to compile without error_resilience
Conflicts:
configure
libavcodec/h264.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Error resilience is enabled by the h264 decoder, unless explicitly
disabled. --disable-everything --enable-decoder=h264 will produce
a h264 decoder with error resilience enabled, while
--disable-everything --enable-decoder=h264 --disable-error-resilience
will produce a h264 decoder with error resilience disabled.
Signed-off-by: Martin Storsjö <martin@martin.st>
This allows dropping the mpegvideo dependency from a number of
components.
This also fixes standalone building of the h264 parser, which
was broken in 64e438697.
Signed-off-by: Martin Storsjö <martin@martin.st>
* qatar/master:
configure: Enable hwaccels without external dependencies by default.
doc/developer: Clarify symbol naming prefixes section.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Dynamically loads the library itself, rather than through VfW.
Supports AvxSynth on Linux and OS X.
Supports the new colorspaces added in AviSynth 2.6 when used
with AviSynth 2.6.
Only compile if CONFIG_ENCODERS is enabled, i.e. if at least one
encoder is to be compiled. This prevents it from being includes in
a decoder-only build.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* commit '2eaa3663fda750dac66d41fe8541a8744d5563a4':
avplay: enable only when SDL 1.2 is found
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Not all gcc configurations have an implementation of all the atomic
operations, and some gcc configurations have some atomic builtins
implemented but not all.
Thus check for the most essential function, whose presence should
indicate that all others are present as well, since it can be used
to implement all the other ones.
Signed-off-by: Martin Storsjö <martin@martin.st>
* commit '65f1d45dcc71186ede72fff950996099d23359bd':
lavu: add support for atomic operations.
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '4be368b504c6f4a03051448728fc62cd0ed506b2':
avstring: Fix isxdigit to not accept non-hex characters
configure: Add missing videodsp dependencies to some decoders
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'bcd0a7137e4aca0f6f598593b90ca8f338444c51':
configure: Add missing h264chroma dependencies to vp5, vp6
Add missing error_resilience includes to files that use ER
Conflicts:
configure
libavcodec/mpeg12.c
libavcodec/mpeg4videodec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Not all gcc configurations have an implementation of all the atomic
operations, and some gcc configurations have some atomic builtins
implemented but not all.
Thus check for the most essential function, whose presence should
indicate that all others are present as well, since it can be used
to implement all the other ones.
Signed-off-by: Martin Storsjö <martin@martin.st>
These could be used for reference counting, or for keeping track of
decoding progress in references in multithreaded decoders.
Support is provided by gcc/msvc/suncc intrinsics, with a fallback using
pthread mutexes.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This makes the decoder independent of mpegvideo.
This copy of the draw_horiz_band code is simplified compared to
the "generic" mpegvideo one which still has a number of special
cases for different codecs.
Signed-off-by: Martin Storsjö <martin@martin.st>
This fixes a possible mis-detection of iconv on OS X.
OS X with macports often has two version of libiconv.2.dylib
installed, one with symbols like "_iconv_open" and one with
"_libiconv_open", so test for iconv with all flags to make
sure the detection uses the same library as the actual
compilation / linking.
Tested-by: Paul Sturbaum
* commit '813b82b927b19532e3bc3397b972c8a27b9f6326':
configure: Fix silly typo in logging command of check_struct()
fate: remove last incomplete frame from mpeg2-field-enc test
Conflicts:
tests/fate/video.mak
tests/ref/fate/mpeg2-field-enc
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* cehoyos/master:
buildsys: only include log2_tab per library for shared builds
Add h264chroma dependency for cavs decoder to configure.
Add h264qpel dependency for snow codec to configure.
Add h264chroma dependency for vp5 and vp6 decoder to configure.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
It seems to break a lot on MacOS because of a mixup between multiple
iconv libraries. The issue is that the configure check link with no
particular library path (so it uses /usr/lib/libiconv.dylib where all
the symbols are defined). OTOH, the final build might link with extra
library paths, such as the ports lib directory (typically you get
-L/opt/local/lib because of an extra library such as SDL). Whatever this
option position (before or after -liconv), it will try to link with
/opt/local/lib/libiconv.dylib, and the issue is that this version has
the same symbols as the ones in /usr/lib/libiconv.dylib except that they
all start with 'lib' (libiconv_open, libiconv_close, ...). I don't plan
to try to workaround this mess, so any better solution is welcome.
* commit 'e951b6d94c441d46b396ef12da1428297d77251d':
vorbisdec: cosmetics: rename variable avccontext to avctx
configure: Identify icc compiler with a less ambiguous pattern
Conflicts:
libavcodec/vorbisdec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'b58b00aeca21de00ab6da2944684f784d9d6bc47':
configure: Separate "ln" command line arguments
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '3fc09b0081184f26edbb62d2d72ae89bf9e21768':
configure: Move list of external libs to a separate variable
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '45235ac488363e3360bf2f2275102d1ec66eba0f':
configure: Move x11grab option to a more suitable place in the help output
lavr: allow setting internal_sample_fmt option by string
lavr: Add "resample_cutoff" option as a duplicate of "cutoff"
Conflicts:
configure
Merged-by: Michael Niedermayer <michaelni@gmx.at>
If you want it back (yeah i want it back too)
then you just need to volunteer to maintain the code in configure
thats related to hwaccel autodetection.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* commit '0a8da1a3e5f0b9329dfb89d17356ff5444c02351':
configure: Do not redundantly list enabled hwaccel libs
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '7432e872066d6960a9fbd31c51a94ebe6183389e':
configure: Add print_3_columns helper function and use where appropriate
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '4db96649ca700db563d9da4ebe70bf9fc4c7a6ba':
avutil: Ensure that emms_c is always defined, even on non-x86
configure: Move MinGW CPPFLAGS setting to libc section, where it belongs
avutil: Move emms code to x86-specific header
Conflicts:
configure
libavutil/internal.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '56dea32f09e71460add14a1b6d0fbe6eb16f02a4':
doc: developer: Fix wording in "naming conventions" section
openbsd: Add minor number to shared library install name
Conflicts:
doc/developer.texi
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '304b806cb524fb040f8e09a241040f1af2cb820b':
build: Make library minor version visible in the Makefile
x86: mpeg4qpel: Make movsxifnidn do the right thing
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '620289a20e022b9c16c10d546ef86cc0bb77cc84':
sh4: Fix silly type vs. variable name search and replace typo
configure: Group all hwaccels together in a separate variable
Add av_cold attributes to arch-specific init functions
Conflicts:
configure
libavcodec/arm/mpegvideo_armv5te.c
libavcodec/x86/mlpdsp.c
libavcodec/x86/motion_est.c
libavcodec/x86/mpegvideoenc.c
libavcodec/x86/videodsp_init.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
x86: hpel: Move {avg,put}_pixels16_sse2 to hpeldsp
configure: Add a comment indicating why uclibc is checked before glibc
Merged-by: Michael Niedermayer <michaelni@gmx.at>
On Cygwin systems MinGW headers can be present if the corresponding
packages have been installed. Since the MinGW libc is checked for
first, this results in newlib getting misdetected as MinGW libc.
* commit '2c10e2a2f62477efaef5b641974594f7df4ca339':
build: Make the H.264 parser select h264qpel
x86: h264qpel: add cpu flag checks for init function
Conflicts:
libavcodec/x86/h264_qpel.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
