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>

This makes struct AVDictionary fully opaque now that nothing
needs to access it directly any more.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

The only compiler I have that does not define the standard
offsetof() macro is "Bruce's C Compiler", a simple compiler
for producing 8/16-bit 8086 code, usually for use in early
stages of PC booting.
Signed-off-by: Mans Rullgard <mans@mansr.com>

This list is incomplete (we also use UINT16_MAX), so there does
not appear to be any system we care about that needs these.
Signed-off-by: Mans Rullgard <mans@mansr.com>

This macro is only used in two places, both in libavcodec, so this
is a more sensible place for it.

Two small tweaks to the macro are made:

- removing the trailing semicolon
- dropping unnecessary 'volatile' from the x86 asm
Signed-off-by: Mans Rullgard <mans@mansr.com>

These x86-specific macros do not belong in generic code.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Mans Rullgard <mans@mansr.com>

This should fix --enable-hardcoded-tables
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This can happen if a application doesnt use ffmpegs configure
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Martin Storsjö <martin@martin.st>

All current usages of it are incompatible with localization.
For example strcasecmp("i", "I") != 0 is possible, but would
break many of the places where it is used.
Instead use our own implementations that always treat the data
as ASCII.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

Rename it to AVDictionary, since it will be used as such.  Tags
documentation and metadata conversion API is lavf-specific, so remains
there.

With unknown attribute warnings disabled, these checks are no
longer needed.  Removing them improves readability while having
no effect on generated code.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

__ICC is not supported on all platforms, this is an Intel documentation
bug that is supposed to be fixed in a future release.
(Intel issue 612289)

See doc/multithreading.txt for details on use in codecs.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

See doc/multithreading.txt for details on use in codecs.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This is consistent with most of the other attribute macros.
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit 365e3c78)

This is consistent with most of the other attribute macros.
Signed-off-by: Mans Rullgard <mans@mansr.com>

dprintf clashes with POSIX.1-2008
(cherry picked from commit dfd2a005)

dprintf clashes with POSIX.1-2008

Intel C compiler 12.0 does not suport these attributes: may_alias, force_align_arg_pointer and alloc_size.

Originally committed as revision 25716 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 24290 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 23911 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 23904 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 23622 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 23615 to svn://svn.ffmpeg.org/ffmpeg/trunk

When symbol versioning is enabled, moving symbols from one library to
another breaks binary compatibility.  This adds wrappers with the old
version tag for the av_*packet functions recently moved to lavc.

Originally committed as revision 23611 to svn://svn.ffmpeg.org/ffmpeg/trunk

also attributes.h is public and external api and can thus not depend
on configure tested compiler support thus this part is removed. A
different solution must be found if this breaks for some compiler
which i hope it does not.

Originally committed as revision 23115 to svn://svn.ffmpeg.org/ffmpeg/trunk

Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.

Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk

This reduces the number of false dependencies on header files and
speeds up compilation.

Originally committed as revision 22407 to svn://svn.ffmpeg.org/ffmpeg/trunk