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Andreas Rheinhardt 3aee27a975 avcodec/jpeglsenc: Only use one line at a time as spare buffer
ls_encode_line() encodes one line of input from left to right and
to do so it uses the values of the left, upper left, upper and upper
right pixels for prediction (i.e. the values that a decoder gets when it
decodes the already encoded part of the picture). So a simple algorithm
would use a buffer that can hold two lines, namely the current line as
well as the last line and swap the pointers to the two lines after
decoding each line. Yet if one is currently encoding the pixel with
index k of a line, one doesn't need any pixel with index < k - 1 of the
last line at all and similarly, no pixels with index >= k have been
written yet. So the overlap in the effective lifetime is pretty limited
and since the last patch (which stopped reading the upper left pixel and
instead reused the value of the upper pixel from the last iteration of
the loop) it is inexistent. Ergo one only needs one line and doesn't
need to swap the lines out.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-03-08 04:28:52 +01:00
2021-03-01 06:10:44 +01:00
2021-03-05 19:45:00 +02:00
2020-07-13 11:24:04 +08:00
2021-03-06 12:42:16 +01:00
2019-12-28 11:20:48 +01:00
2021-01-20 01:04:26 -06:00

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.

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