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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-02-04 06:08:26 +02:00
Andreas Rheinhardt c801ab43c3 avformat/hlsenc: Improve checks for invalid stream mappings
The mapping of streams to the various variant streams to be created by
the HLS muxer is roughly as follows: Space and tab separate variant
stream group maps while the entries in each variant stream group map are
separated by ','.

The parsing process of each variant stream group proceeded as follows:
At first the number of occurences of "a:", "v:" and "s:" in each variant
stream group is calculated so that one can can allocate an array of
streams with this number of entries. Then each entry is checked and the
check for stream numbers was deficient: It did check that there is a
number beginning after the ":", but it did not check that the number
extends until the next "," (or until the end).

This means that an invalid variant stream group like v:0_v:1 will not be
rejected; the problem is that the variant stream in this example is
supposed to have two streams associated with it (because it contains two
"v:"), yet only one stream is actually associated with it (because there
is no ',' to start a second stream specifier). This discrepancy led to
segfaults (null pointer dereferencing) in the rest of the code (when the
nonexistent second stream associated to the variant stream was inspected).

Furthermore, this commit also removes an instance of using atoi() whose
behaviour on a range error is undefined.

Fixes ticket #8652.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-05-06 08:47:35 +02:00
2020-03-31 04:14:14 -05:00
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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