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Sebastian Pop c3a17ffff6 swscale/aarch64: use multiply accumulate and shift-right narrow
This patch rewrites the innermost loop of ff_yuv2planeX_8_neon to avoid zips and
horizontal adds by using fused multiply adds. The patch also uses ld1r to load
one element and replicate it across all lanes of the vector. The patch also
improves the clipping code by removing the shift right instructions and
performing the shift with the shift-right narrow instructions.

I see 8% difference on an m6g instance with neoverse-n1 CPUs:
$ ffmpeg -nostats -f lavfi -i testsrc2=4k:d=2 -vf bench=start,scale=1024x1024,bench=stop -f null -
before: t:0.014015 avg:0.014096 max:0.015018 min:0.013971
after:  t:0.012985 avg:0.013013 max:0.013996 min:0.012818

Tested with `make check` on aarch64-linux.

Signed-off-by: Sebastian Pop <spop@amazon.com>
Reviewed-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2020-01-04 20:59:31 +01:00
compat compat/avisynth: Fix unicode compilation. 2020-01-01 16:38:28 +01:00
doc doc: Fix a typo. 2020-01-04 20:58:10 +01:00
ffbuild build: add support for building CUDA files with clang 2019-08-04 19:08:08 +02:00
fftools fftools/ffmpeg_filter: remove sws_param option from buffersrc 2019-12-31 14:24:34 +01:00
libavcodec avcodec/bsf: replace ctx->internal-> with bsfi-> for better readability 2020-01-04 20:59:31 +01:00
libavdevice avdevice/decklink: deprecate the -list_devices option 2020-01-03 18:13:22 +01:00
libavfilter lavfi/buffersrc: Remove redundant free after ff_filter_frame() failure 2020-01-04 19:37:39 +01:00
libavformat avformat/img2enc: fix writing multiple streams in write_muxed_file 2020-01-03 11:23:55 +01:00
libavresample avresample: remove deprecated attribute from the AVAudioResampleContext struct 2018-01-09 10:56:53 -03:00
libavutil libavutil/opt: fix memory leak after av_dict_parse_string fail 2020-01-04 09:05:23 +08:00
libpostproc Bump minor versions again on master to keep 4.2 versions separate from master 2019-07-21 18:36:31 +02:00
libswresample swresample/audioconvert: fix invalid left shift for 64bit sample format 2019-09-26 16:22:47 +02:00
libswscale swscale/aarch64: use multiply accumulate and shift-right narrow 2020-01-04 20:59:31 +01:00
presets
tests avformat/matroskadec: Fix lzo decompression 2019-12-28 22:40:13 -03:00
tools tools/target_dec_fuzzer: Stop negative block_align and sampling rate 2019-12-31 12:37:47 +01:00
.gitattributes
.gitignore tools/python: add script to convert TensorFlow model (.pb) to native model (.model) 2019-07-01 10:23:47 -03:00
.travis.yml Merge commit '899ee03088d55152a48830df0899887f055da1de' 2019-03-14 15:53:16 -03:00
Changelog avfilter: add thistogram video filter 2019-12-29 15:33:55 +01:00
configure configure: bump year 2020-01-01 12:14:30 +05:30
CONTRIBUTING.md
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
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 myself as libxavs2 maintainer 2019-12-07 19:34:57 +01:00
Makefile tools: add a fuzzer tool for bitstream filters 2019-12-05 20:49:15 -03:00
README.md
RELEASE RELEASE: Update value for post 4.2 branch 2019-07-21 18:37:32 +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.