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Andreas Rheinhardt 3899adc298 avcodec/smacker: Remove redundant checks when reading VLC codes
The VLC codes in question originate from a Huffmann tree and so every
sequence of bits that is longer than the longest code contains an
initial sequence that is a valid code. Given that it has been checked
during reading said tree (and once again in ff_init_vlc_sparse()) that
the length of each code is <= 3 * the number of bits read at once when
reading codes, get_vlc2() will always find a matching entry.

These checks have been added in 71d3c25a7e
at a time when the length of the codes had not been checked when parsing
the tree.

For GCC 9 and the sample from ticket #2425 this led to a slight
performance regression: The time for one call to smka_decode_frame()
increased from 2053671 to 2064529 decicycles; for Clang 9, performance
improved from 1521288 to 1508459 decicycles.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-09-18 02:00:34 +02:00
compat compat/cuda/ptx2c: remove shell loop; fix BSD sed compat 2020-06-01 22:10:41 -05:00
doc avdevice/decklink_dec: add support for querying RP188 High Frame Rate timecode 2020-09-13 18:06:54 +02:00
ffbuild ffbuild: Refine MIPS handling 2020-07-23 16:30:02 +02:00
fftools fftools/ffprobe: use av_timecode_make_smpte_tc_string2 2020-09-13 17:51:57 +02:00
libavcodec avcodec/smacker: Remove redundant checks when reading VLC codes 2020-09-18 02:00:34 +02:00
libavdevice avdevice/decklink_dec: fix build with older SDK 2020-09-15 22:07:26 +02:00
libavfilter avfilter/vf_showinfo: add const to the AVFrameSideData instance 2020-09-17 18:52:11 +08:00
libavformat avformat/3dostr: make probing more robust 2020-09-17 23:47:10 +02:00
libavresample
libavutil avutil/cuda_check: add missing dynlink_loader.h include 2020-09-15 19:29:37 -03:00
libpostproc Bump minor versions after branching 4.3 2020-06-08 22:49:04 +02:00
libswresample swresample/rematrix: handle 22.2 as a 9 channel layout 2020-08-18 22:47:35 +03:00
libswscale swscale/x86/output: add missing AVX2 support preprocessor wrappers 2020-08-20 15:14:56 -03:00
presets
tests avformat/mxfdec: Read Apple private Content Light Level from MXF 2020-09-17 21:40:25 +02:00
tools tools:target_dem_fuzzer: Split into a fuzzer fuzzing at the protocol level and one fuzzing a fixed demuxer input 2020-09-13 10:40:02 +02:00
.gitattributes
.gitignore tools/python: add script to convert TensorFlow model (.pb) to native model (.model) 2019-07-01 10:23:47 -03:00
.mailmap mailmap: add entry for myself 2020-07-13 11:24:04 +08:00
.travis.yml Merge commit '899ee03088d55152a48830df0899887f055da1de' 2019-03-14 15:53:16 -03:00
Changelog avformat: add Argonaut Games BRP demuxer 2020-09-14 14:38:45 +10:00
configure avcodec: add AV1 hardware accelerated decoder 2020-09-12 13:08:34 -03:00
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 avformat: add Argonaut Games BRP demuxer 2020-09-14 14:38:45 +10:00
Makefile tools:target_dem_fuzzer: Split into a fuzzer fuzzing at the protocol level and one fuzzing a fixed demuxer input 2020-09-13 10:40:02 +02:00
README.md
RELEASE RELEASE: We are after the 4.3 branch point, update for that 2020-06-10 00:20:24 +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 a mean to alter decoded Audio and Video through chain of 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.