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Janne Grunau
d3b9fd51b8
aarch64: vp9mc: Load only 12 pixels in the 4 pixel wide horizontal filter
This reduces the amount the horizontal filters read beyond the filter width to a consistent 1 pixel. The data is not used so this is usually not noticeable. It becomes a problem when the application allocates frame buffers only for the aligned picture size and the end of it is at a page boundary. This happens for picture sizes which are a multiple of the page size like 1280x640. The frame buffer allocation is based on its most likely done via mmap + MAP_ANONYMOUS so start and end of the buffer are page aligned and the previous and next page are not necessarily mapped. Under these conditions like seen by Firefox a read beyond the end of the buffer results in a segfault. After the over-read is reduced to a single pixel it's reasonable to use VP9's emulated edge motion compensation for this. Fixes: https://bugzilla.mozilla.org/show_bug.cgi?id=1881185 Signed-off-by: Janne Grunau <janne-ffmpeg@jannau.net> Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com> (cherry picked from commit 430c38f698a65d597e863330810b05e083682be6)
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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.
Languages
C
90.3%
Assembly
7.8%
Makefile
1.3%
C++
0.2%
Objective-C
0.2%
Other
0.1%