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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-02-20 07:48:15 +02:00
Andreas Rheinhardt a3a2e782c2 lavf/webm_chunk: Fix NULL dereference
The earlier version of the webm_chunk muxer had several bugs:

1. If the first packet of an audio stream didn't have a PTS of zero,
then no chunk will be started before a packet is delivered to the
underlying Matroska/WebM muxer, i.e. the AVFormatContext used to write
these packets had a NULL as AVIOContext for output. This is behind the
crash in ticket #5752.

2. If an error happens during writing a packet, the underlyimg
Matroska/WebM muxer context is freed. This leads to a use-after-free
coupled with a double-free in webm_chunk_write_trailer (which supposes
that the underlying AVFormatContext is still valid).

3. Even when no error occurs at all, webm_chunk_write_trailer is still
buggy: After the underlying Matroska/WebM muxer has written its trailer,
ending the chunk implicitly flushes it again which is illegal at this
point.

These bugs have been fixed.

Fixes #5752.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
(cherry picked from commit 8c6ee7626bcce7c270360f33b60dc7ef99939fc3)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-07-03 00:03:45 +02:00
2019-11-15 17:19:45 +01:00
2018-06-18 01:16:03 +02:00
2017-01-27 17:06:42 +01:00
2019-12-01 18:24:40 +01:00
2020-07-02 19:55:09 +02:00
2016-09-18 10:02:13 +01:00
2014-05-28 22:38:38 +02:00
2016-09-18 10:02:13 +01:00
2019-11-15 17:19:45 +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.
  • ffserver is a multimedia streaming server for live broadcasts.
  • 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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