FFmpeg

Commit Graph

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>	12 years ago
Samuel Pitoiset	a0845bae49	mjpeg: Rename some symbols to avpriv_* instead of ff_* These symbols will be used from the RTP/JPEG depacketizer. Signed-off-by: Martin Storsjö <martin@martin.st>	12 years ago
Mans Rullgard	2912e87a6c	Replace FFmpeg with Libav in licence headers Signed-off-by: Mans Rullgard <mans@mansr.com>	14 years ago
Diego Biurrun	ba87f0801d	Remove explicit filename from Doxygen @file commands. 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	15 years ago
Stefano Sabatini	b275500706	Split bitstream.h, put the bitstream writer stuff in the new file put_bits.h. Originally committed as revision 18461 to svn://svn.ffmpeg.org/ffmpeg/trunk	16 years ago
Diego Biurrun	bad5537e2c	Use full internal pathname in doxygen @file directives. Otherwise doxygen complains about ambiguous filenames when files exist under the same name in different subdirectories. Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk	16 years ago
Diego Biurrun	406792e7b0	cosmetics: Remove pointless period after copyright statement non-sentences. Originally committed as revision 16684 to svn://svn.ffmpeg.org/ffmpeg/trunk	16 years ago
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	17 years ago
Stefan Gehrer	5a89396989	remove duplicate tables Originally committed as revision 13959 to svn://svn.ffmpeg.org/ffmpeg/trunk	17 years ago
Diego Biurrun	5b21bdabe4	Add FFMPEG_ prefix to all multiple inclusion guards. Originally committed as revision 10765 to svn://svn.ffmpeg.org/ffmpeg/trunk	17 years ago
Diego Biurrun	7b94177e37	Group all copyright and author notices together. Originally committed as revision 9483 to svn://svn.ffmpeg.org/ffmpeg/trunk	18 years ago
Aurelien Jacobs	bf406d90e4	move MJpegDecodeContext declaration from mjpeg.h to mjpegdec.h Originally committed as revision 9074 to svn://svn.ffmpeg.org/ffmpeg/trunk	18 years ago
Aurelien Jacobs	944721c160	add proper prefix to new mjpeg extern func/var Originally committed as revision 9049 to svn://svn.ffmpeg.org/ffmpeg/trunk	18 years ago
Aurelien Jacobs	4922a5b0ee	split mjpeg.c into an encoder and a decoder file Originally committed as revision 9048 to svn://svn.ffmpeg.org/ffmpeg/trunk	18 years ago
Aurelien Jacobs	6ba04c2b03	split jpeg_ls into jpeglsdec, jpeglsenc and jpegls Originally committed as revision 9021 to svn://svn.ffmpeg.org/ffmpeg/trunk	18 years ago

15 Commits (7f83959598b6565baa0091e5739dd9091ab7a990)