From SMPTE RDD 5-2006, the grain seed is to be computed from the following definition of `pic_offset`: > When decoding H.264 | MPEG-4 AVC bitstreams, pic_offset is defined as > follows: > - pic_offset = PicOrderCnt(CurrPic) + (PicOrderCnt_offset << 5) > where: > - PicOrderCnt(CurrPic) is the picture order count of the current frame, > which shall be derived from [the video stream]. > > - PicOrderCnt_offset is set to idr_pic_id on IDR frames. idr_pic_id > shall be read from the slice header of [the video stream]. On non-IDR I > frames, PicOrderCnt_offset is set to 0. A frame shall be classified as I > frame when all its slices are I slices, which may be optionally > designated by setting primary_pic_type to 0 in the access delimiter NAL > unit. Otherwise, PicOrderCnt_offset it not changed. PicOrderCnt_offset is > updated in decoding order. Co-authored-by: James Almer <jamrial@gmail.com> Signed-off-by: Niklas Haas <git@haasn.dev> Signed-off-by: James Almer <jamrial@gmail.com>
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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
andqt-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.
Description
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