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Martin Storsjö e4ac156b7c libavcodec: Set hidden visibility on global symbols accessed from AArch64 assembly
The AArch64 assembly accesses those symbols directly, without
indirection via e.g. the GOT on ELF. In order for this not to
require text relocations, those symbols need to be resolved fully
at link time, i.e. those symbols can't be interposable.

Normally, so far, this is achieved when linking shared libraries
in two ways; we have a version script (libavcodec/libavcodec.v) which
marks all symbols that don't start with av* as local. Additionally,
we try to add -Wl,-Bsymbolic to the linker options if supported,
making sure that such symbol references are resolved fully at link
time, instead of making them interposable.

When the libavcodec static library is linked into another shared
library, there's no guarantee that it uses similar options (even though
that would be favourable), which would end up requiring text relocations
in the AArch64 assembly.

Explicitly mark the symbols that are accessed from AArch64 assembly
as hidden, so that they are resolved fully at link time even without
the version script and -Wl,-Bsymbolic.

Signed-off-by: Martin Storsjö <martin@martin.st>
2022-09-02 23:13:29 +03:00
compat compat: add msvc windres wrapper 2022-08-13 14:42:52 +02:00
doc doc/git-howto.texi: Document commit signing 2022-08-28 22:06:45 +02:00
ffbuild ffbuild/common: Fix CPPFLAGS applied for compiling C++ files 2022-05-24 21:30:52 +02:00
fftools fftools/ffmpeg_opt: Check creation of new program 2022-09-01 14:26:01 +02:00
libavcodec libavcodec: Set hidden visibility on global symbols accessed from AArch64 assembly 2022-09-02 23:13:29 +03:00
libavdevice configure: always enable gnu_windres if available 2022-08-13 14:42:36 +02:00
libavfilter avfilter/af_silenceremove: do not trim non-silence from start 2022-08-23 22:18:02 +02:00
libavformat avcodec/flac: Don't use bytestream API unnecessarily 2022-09-02 11:55:22 +02:00
libavutil libavcodec: Set hidden visibility on global symbols accessed from AArch64 assembly 2022-09-02 23:13:29 +03:00
libpostproc configure: always enable gnu_windres if available 2022-08-13 14:42:36 +02:00
libswresample lswr: take const AVChannelLayout* in swr_alloc_set_opts2() 2022-08-24 18:31:05 -05:00
libswscale libswscale: add support for VUYX format 2022-08-25 19:03:49 -07:00
presets
tests libswscale: add support for VUYX format 2022-08-25 19:03:49 -07:00
tools tools/target_dec_fuzzer: Adjust threshold for MVDV 2022-08-28 22:06:45 +02:00
.gitattributes
.gitignore gitignore: add config_components.h 2022-03-17 18:35:41 -03:00
.mailmap mailmap: add entry for myself 2021-03-09 02:09:55 +00:00
.travis.yml Merge commit '899ee03088' 2019-03-14 15:53:16 -03:00
Changelog lavc/vaapi_encode: enable 8bit 4:4:4 encoding for HEVC and VP9 2022-08-09 09:22:49 -07:00
configure configure: enable the av1_frame_split bsf for the av1 decoder 2022-08-23 14:30:28 +02:00
CONTRIBUTING.md
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
INSTALL.md
LICENSE.md avfilter/vf_geq: Relicense to LGPL 2019-12-28 11:20:48 +01:00
MAINTAINERS MAINTAINERS: Add ED25519 key for signing my commits in the future 2022-08-09 21:57:31 +02:00
Makefile Makefile: Prompt for reconfigure on lavc/hwaccels.h modification 2022-07-01 00:34:38 +02:00
README.md README: fix typo and description of libavfilter 2021-10-08 09:44:34 +05:30
RELEASE RELEASE: update after 5.1 branch 2022-07-13 00:31:42 +02:00

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.