Commit Graph

22 Commits

Author SHA1 Message Date
Martin Storsjö
d66c52c2b3 Add support for building shared libraries with MSVC
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>
2012-10-18 14:26:15 +03:00
Diego Biurrun
e4cbf7529b Give all anonymously typedeffed structs in headers a name
Anonymous structs cannot be forward declared and have no benefit.
2012-10-06 09:27:11 +02:00
Janne Grunau
fd095539d1 latmdec: fix audio specific config parsing
Pass the correct size in bits to mpeg4audio_get_config and add a flag
to disable parsing of the sync extension when the size is not known.

Latm with AudioMuxVersion 0 does not specify the size of the audio
specific config. Data after the audio specific config can be
misinterpreted as sync extension resulting in random and wrong configs.
2011-12-03 00:42:48 +01:00
Anton Khirnov
59a9a23581 lavc: use avpriv_ prefix for some mpeg4audio symbols used in lavf.
Specifically, ff_mpeg4audio_sample_rates, ff_mpeg4audio_get_config and
ff_copy_pce_data
2011-10-20 21:06:57 +02:00
Diego Biurrun
0249478756 doxygen: fix wrong comment syntax, //< vs. ///< 2011-08-26 18:34:28 +02:00
Mans Rullgard
2912e87a6c Replace FFmpeg with Libav in licence headers
Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-03-19 13:33:20 +00:00
Young Han Lee
ead15f1dc1 aacdec: Implement LTP support.
Ported from gsoc svn.
2011-02-14 21:43:42 -08:00
Alex Converse
d14662f66a Add support for PS sync extensions.
Originally committed as revision 22818 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-04-08 06:04:41 +00:00
Alex Converse
ed492b61db Add an HE-AAC v1 decoder.
A large portion of this code was orignally authored by Robert Swain. The rest
was written by me. Full history is available at:
svn://svn.ffmpeg.org/soc/aac-sbr
http://github.com/aconverse/ffmpeg-heaac/tree/sbr_pub

Originally committed as revision 22316 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-08 04:33:02 +00:00
Alex Converse
07580347b9 Mark AOT_ALS as a supported MPEG-4 audio object type.
Originally committed as revision 20524 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-12 05:22:51 +00:00
Alex Converse
e92ad83f54 Cosmetics: Remove the implied gap before AOT_USAC in the MPEG-4 AOT enum.
Originally committed as revision 20514 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-11 20:36:42 +00:00
Alex Converse
5aea268d14 Add a channels field to MPEG4AudioConfig.
Originally committed as revision 20512 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-11 20:24:23 +00:00
Alex Converse
4312b9367a Add Low Delay MPEG Surround to the enum of MPEG-4 Audio Object Types.
Originally committed as revision 20510 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-11-11 01:04:08 +00:00
Alex Converse
8ba939d702 Mark the AOT escape value as supported.
Originally committed as revision 19662 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-08-17 00:15:02 +00:00
Alex Converse
08dac48d61 Add USAC and SAOC AOTs to the AudioObjectType enum.
Originally committed as revision 19661 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-08-17 00:14:10 +00:00
Alex Converse
107815de42 Subroutine to copy an AAC Program Config Element (PCE)
Originally committed as revision 18817 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-05-13 22:57:30 +00:00
Jai Menon
3d10a8904d Read extended channel configuration when extended AOT is BSAC.
Originally committed as revision 18644 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-04-21 17:52:52 +00:00
Alex Converse
2b823a5299 Fix typo in AOT_ER_AAC_ELD
Originally committed as revision 18034 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-03-18 14:14:56 +00:00
Alex Converse
d3487e472e Update the MPEG-4 AOT table.
Originally committed as revision 18033 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-03-18 14:11:05 +00:00
Alex Converse
f650e4d34a Move MPEG-4 AOT enum to mpeg4audio.h.
Originally committed as revision 18031 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-03-18 13:52:56 +00:00
Stefano Sabatini
987903826b Globally rename the header inclusion guard names.
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.'  to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".

Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-08-31 07:39:47 +00:00
Baptiste Coudurier
4d34bb19c1 mpeg4audio common code
Originally committed as revision 12662 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-04-01 12:01:40 +00:00