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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-02-04 06:08:26 +02:00
Takio Yamaoka cc6c56f5d9 avcodec/libx264: fix chroma quantizer offset usage
The default for the chromaoffset field in AVCodecContext
is zero, which until now always ended up overriding the
AVOption-set value, thus leading to the AVOption not working.

Additionally, the previous usage prevented the usage of
negative values, while both the variable as well as x264's
API would successfully handle such.

Thus, the default value of the AVOption is changed to match
the default of x264 (and what is currently the default for
the AVCodecContext chromaoffset field), and the checks are
changed to check for nonzero values.

This way:
1. the library default is still utilized if the value is zero.
2. both negative and positive values are correctly passed to
   x264.

For historical context, this was initially similarly
implemented in 5764d38173661c29d954711dd5abfddf709e9ba4, and
then b340bd8a58c32453172404a8e4240e3317e341da broke the
value.

Partially reverts commit b340bd8a58c32453172404a8e4240e3317e341da.

Signed-off-by: Takio Yamaoka <y.takio@gmail.com>
2020-08-06 13:09:23 +03:00
2020-07-23 16:30:02 +02:00
2020-07-25 10:20:42 +08:00
2020-07-13 11:24:04 +08:00
2020-08-02 09:33:24 +02:00
2020-07-31 22:30:35 +01:00
2019-12-28 11:20:48 +01:00

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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