Ganesh Ajjanagadde e9c7493f19 avfilter/vsrc_mandelbrot: avoid sqrt for epsilon calculation
This rewrites into a similar expression avoiding sqrt. Similarity is
assured since sqrt(x^2 + y^2)/(x+y) lies in [1/sqrt(2), 1] for x, y > 0.

Tested on x86-64, Haswell, GNU/Linux.
Command:
ffmpeg -f lavfi -i mandelbrot -f null -

old (draw_mandelbrot):
277625266 decicycles in draw_mandelbrot,     256 runs,      0 skips
304527322 decicycles in draw_mandelbrot,     512 runs,      0 skips
377593582 decicycles in draw_mandelbrot,    1024 runs,      0 skips
338539499 decicycles in draw_mandelbrot,    2048 runs,      0 skips
583630357 decicycles in draw_mandelbrot,    4096 runs,      0 skips

new (draw_mandelbrot):
274635709 decicycles in draw_mandelbrot,     256 runs,      0 skips
300287046 decicycles in draw_mandelbrot,     512 runs,      0 skips
371819935 decicycles in draw_mandelbrot,    1024 runs,      0 skips
336663765 decicycles in draw_mandelbrot,    2048 runs,      0 skips
581851016 decicycles in draw_mandelbrot,    4096 runs,      0 skips

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
2015-11-24 20:36:40 -05:00
2015-11-12 22:31:46 +01:00
2015-11-21 21:03:51 +01:00
2014-05-28 22:38:38 +02:00
2015-07-08 14:35:02 +02:00
2015-09-20 19:54:57 +02:00
2015-11-07 16:43:36 +01:00
2015-10-06 13:27:29 +02:00
2015-09-09 23:53:15 -03:00

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.
  • ffserver is a multimedia streaming server for live broadcasts.
  • 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. Few developers follow pull requests so they will likely be ignored.

Description
No description provided
Readme 173 MiB
Languages
C 92.1%
Assembly 6%
Makefile 1.2%
C++ 0.3%
Objective-C 0.2%
Other 0.1%