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Andreas Rheinhardt 20b0d24c2f Makefile: Redo duplicating object files in shared builds
In case of shared builds, some object files containing tables
are currently duplicated into other libraries: log2_tab.c,
golomb.c, reverse.c. The check for whether this is duplicated
is simply whether CONFIG_SHARED is true. Yet this is crude:
E.g. libavdevice includes reverse.c for shared builds, but only
needs it for the decklink input device, which given that decklink
is not enabled by default will be unused in most libavdevice.so.

This commit changes this by making it more explicit about what
to duplicate from other libraries. To do this, two new Makefile
variables were added: SHLIBOBJS and STLIBOBJS. SHLIBOBJS contains
the objects that are duplicated from other libraries in case of
shared builds; STLIBOBJS contains stuff that a library has to
provide for other libraries in case of static builds. These new
variables provide a way to enable/disable with a finer granularity
than just whether shared builds are enabled or not. E.g. lavd's
Makefile now contains: SHLIBOBJS-$(CONFIG_DECKLINK_INDEV) += reverse.o

Another example is provided by the golomb tables. These are provided
by lavc for static builds, even if one uses a build configuration
that makes only lavf use them. Therefore lavc's Makefile contains
STLIBOBJS-$(CONFIG_MXF_MUXER) += golomb.o, whereas lavf's Makefile
has a corresponding SHLIBOBJS-$(CONFIG_MXF_MUXER) += golomb_tab.o.
E.g. in case the MXF muxer is the only component needing these tables
only libavformat.so will contain them for shared builds; currently
libavcodec.so does so, too.
(There is currently a CONFIG_EXTRA group for golomb. But actually
one would need two groups (golomb_avcodec and golomb_avformat) in
order to know when and where to include these tables. Therefore
this commit uses a Makefile-based approach for this and stops
using these groups for the users in libavformat.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-01-04 05:01:04 +01:00
compat Replace all occurences of av_mallocz_array() by av_calloc() 2021-09-20 01:03:52 +02:00
doc doc/APIchanges: Fill in missing things 2022-01-03 22:01:36 +01:00
ffbuild Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
fftools fftools: provide media type info for devices 2021-12-24 14:06:56 +05:30
libavcodec Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
libavdevice Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
libavfilter Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
libavformat Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
libavutil lib*/version.h: Bump Versions after release/5.0 branch 2022-01-03 22:10:46 +01:00
libpostproc lib*/version.h: Bump Versions after release/5.0 branch 2022-01-03 22:10:46 +01:00
libswresample Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
libswscale Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
presets
tests fate/libswcale: add missing samples dependency to sws-slice tests 2022-01-03 09:42:38 -03:00
tools tools/target_dec_fuzzer: Adjust threshold for prores 2021-12-16 21:06:47 +01:00
.gitattributes fate: add SCC test 2017-01-27 17:06:42 +01:00
.gitignore build: detect Metal.framework and build .metal files 2021-12-18 11:55:47 -08:00
.mailmap mailmap: add entry for myself 2021-03-09 02:09:55 +00:00
.travis.yml Merge commit '899ee03088d55152a48830df0899887f055da1de' 2019-03-14 15:53:16 -03:00
CONTRIBUTING.md Add CONTRIBUTING.md 2016-09-18 10:02:13 +01:00
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
Changelog avfilter: add anlmf filter 2021-12-25 11:32:41 +01:00
INSTALL.md INSTALL.md: Fix Markdown formatting 2019-01-31 10:29:16 -09:00
LICENSE.md avfilter/vf_geq: Relicense to LGPL 2019-12-28 11:20:48 +01:00
MAINTAINERS MAINTAINERS: add my gpg fingerprint 2021-12-23 09:25:16 +08:00
Makefile Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00
README.md README: fix typo and description of libavfilter 2021-10-08 09:44:34 +05:30
RELEASE Bump Versions before release/4.4 branch 2021-03-20 01:01:12 +01:00
configure Makefile: Redo duplicating object files in shared builds 2022-01-04 05:01:04 +01:00

README.md

FFmpeg README

FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.

Libraries

  • libavcodec provides implementation of a wider range of codecs.
  • libavformat implements streaming protocols, container formats and basic I/O access.
  • libavutil includes hashers, decompressors and miscellaneous utility functions.
  • libavfilter provides means to alter decoded audio and video through a directed graph of connected filters.
  • libavdevice provides an abstraction to access capture and playback devices.
  • libswresample implements audio mixing and resampling routines.
  • libswscale implements color conversion and scaling routines.

Tools

  • ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
  • ffplay is a minimalistic multimedia player.
  • ffprobe is a simple analysis tool to inspect multimedia content.
  • Additional small tools such as aviocat, ismindex and qt-faststart.

Documentation

The offline documentation is available in the doc/ directory.

The online documentation is available in the main website and in the wiki.

Examples

Coding examples are available in the doc/examples directory.

License

FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.

Contributing

Patches should be submitted to the ffmpeg-devel mailing list using git format-patch or git send-email. Github pull requests should be avoided because they are not part of our review process and will be ignored.