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FFmpeg git repo
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Rémi Denis-Courmont 6ab4b92e82 lavc/flacdsp: optimise RVV vector type for lpc16 
This calculates the optimal vector type value at run-time based on the
hardware vector length and the FLAC LPC prediction order. In this
particular case, the additional computation is easily amortised over
the loop iterations:

T-Head C908:
    C     V before  V after
 1   48.0    214.7     95.2
 2   64.7    214.2     94.7
 3   79.7    213.5     94.5
 4   96.2    196.5     94.2 #
 5  111.0    195.7    118.5
 6  127.0    211.2    102.0
 7  143.7    194.2    101.5
 8  175.7    193.2    101.2 #
 9  176.2    224.2    126.0
10  191.5    192.0    125.5
11  224.5    191.2    124.7
12  223.0    190.2    124.2
13  239.2    189.5    123.7
14  253.7    188.7    139.5
15  286.2    188.0    122.7
16  284.0    187.0    122.5 #
17  300.2    186.5    186.5
18  314.0    185.5    185.7
19  329.7    184.7    185.0
20  343.0    184.2    184.2
21  358.7    199.2    183.7
22  371.7    182.7    182.7
23  387.5    181.7    182.0
24  400.7    181.0    181.2
25  431.5    180.2    196.5
26  443.7    195.5    196.0
27  459.0    178.7    196.2
28  470.7    177.7    194.2
29  470.0    177.0    193.5
30  481.2    176.2    176.5
31  496.2    175.5    175.7
32  507.2    174.7    191.0 #

 # Power of two boundary.

With 128-bit vectors, improvements are expected for the first two
test cases only. For the other two, there is overhead but below noise.
Improvements should be better observable with prediction order of 8
and less, or on hardware with larger vector sizes.
2024-05-19 18:37:33 +03:00
compat avutil/common: Don't auto-include mem.h 2024-03-31 00:08:43 +01:00
doc riscv: add Zvbb vector bit manipulation extension 2024-05-11 11:38:49 +03:00
ffbuild riscv: add Zvbb vector bit manipulation extension 2024-05-11 11:38:49 +03:00
fftools fftools/ffplay: Check return of swr_alloc_set_opts2() 2024-05-09 16:17:40 +02:00
libavcodec lavc/flacdsp: optimise RVV vector type for lpc16 2024-05-19 18:37:33 +03:00
libavdevice lavd/v4l2: Use proper field type for second parameter of ioctl() with BSD's 2024-05-08 21:33:32 +02:00
libavfilter avfilter/dnn: Refactor DNN parameter configuration system 2024-05-18 19:44:50 +08:00
libavformat avformat/aacdec: strictly conform to K&R style 2024-05-19 01:26:40 +02:00
libavutil lavu/riscv: add assembler macros for adjusting vector LMUL 2024-05-19 18:37:33 +03:00
libpostproc avutil/common: Don't auto-include mem.h 2024-03-31 00:08:43 +01:00
libswresample avutil/common: Don't auto-include mem.h 2024-03-31 00:08:43 +01:00
libswscale swscale/riscv: explicitly require Zbb for MIN 2024-05-10 18:59:06 +03:00
presets
tests avcodec/decode: Set KEY flag+pict_type generically for intra-only codecs 2024-05-19 11:39:45 +02:00
tools tools/target_enc_fuzzer: Only read pix_fmts if its set 2024-05-09 16:17:39 +02:00
.gitattributes
.gitignore
.mailmap .mailmap: Update my mailmap entry 2024-02-23 00:17:21 +01:00
Changelog lavc/qsvenc: add support for oneVPL string API 2024-05-07 11:06:37 +08:00
configure configure: split ISOBMFF writer helpers into a separate component 2024-05-18 13:21:35 -03:00
CONTRIBUTING.md
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
INSTALL.md
LICENSE.md
MAINTAINERS MAINTAINERS: add myself as *BSD maintainer 2024-05-13 03:40:16 +02:00
Makefile riscv: add Zvbb vector bit manipulation extension 2024-05-11 11:38:49 +03:00
README.md
RELEASE RELEASE: update after 7.0 branch 2024-04-02 13:02:39 -03:00

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.