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Andreas Rheinhardt bd7dea3f4f avformat/matroskaenc: Don't waste bytes writing durations
Tags in the Matroska file format can be summarized as follows: There is
a level 1-element called Tags containing one or many Tag elements each
of which in turn contain a Targets element and one or many SimpleTags.
Each SimpleTag roughly corresponds to a single key-value pair similar to
an AVDictionaryEntry. The Targets meanwhile contains information to what
the metadata contained in the SimpleTags contained in the containing Tag
applies (i.e. to the file as a whole or to an individual track).

The Matroska muxer writes such metadata. It puts the metadata of every
stream into a Tag whose Targets makes it point to the corresponding
track. And if the output is seekable, then it also adds another Tag for
each track whose Targets corresponds to the track and where it reserves
space in a SimpleTag to write the duration at the end of the muxing
process into.

Yet there is no reason to write two Tag elements for a track and a few
bytes (typically 24 bytes per track) can be saved by adding the duration
SimpleTag to the other Tag of the same track (if it exists).

FATE has been updated because the output files changed. (Tests that
write to unseekable output (pipes) needn't be updated (no duration tag
has ever been written for them) and the same applies to tests without
further metadata.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-04-13 08:08:42 +02:00
compat compat/avisynth: remove avisynth headers 2020-04-05 01:17:55 +02:00
doc doc/filters: clarify metadata and logging for blackdetect 2020-04-13 11:23:24 +05:30
ffbuild common.mak: Also clean Windows debug files. 2020-03-21 18:46:00 +01:00
fftools fftools/ffmpeg: also flush encoders which have a variable frame size 2020-04-13 00:31:24 +02:00
libavcodec avcodec/cbs: Avoid leaving the ... out in calls to variadic macros 2020-04-12 23:23:49 +02:00
libavdevice avdevice/decklink_dec: increase autodetect timeout to 3 sec 2020-04-04 22:28:05 +02:00
libavfilter doc/filters: clarify metadata and logging for blackdetect 2020-04-13 11:23:24 +05:30
libavformat avformat/matroskaenc: Don't waste bytes writing durations 2020-04-13 08:08:42 +02:00
libavresample avresample: remove deprecated attribute from the AVAudioResampleContext struct 2018-01-09 10:56:53 -03:00
libavutil lavu/mem: Make other alloc functions more similar to av_malloc(). 2020-04-12 22:32:03 +02:00
libpostproc libavcodec, libpostproc: Remove outcommented START/STOP_TIMER 2020-03-14 18:24:04 +01:00
libswresample Silence "string-plus-int" warning shown by clang. 2020-01-06 22:38:56 +01:00
libswscale swscale/yuv2rgb: Fix vertical dither offset with slices 2020-04-12 16:36:47 +02:00
presets
tests avformat/matroskaenc: Don't waste bytes writing durations 2020-04-13 08:08:42 +02:00
tools tools/target_dec_fuzzer: Adjust threshold for zerocodec 2020-04-12 16:36:47 +02:00
.gitattributes
.gitignore tools/python: add script to convert TensorFlow model (.pb) to native model (.model) 2019-07-01 10:23:47 -03:00
.mailmap mailmap: fix 3-address entries 2020-03-31 04:14:14 -05:00
.travis.yml Merge commit '899ee03088d55152a48830df0899887f055da1de' 2019-03-14 15:53:16 -03:00
Changelog Changelog: Add entry for expanded styling support in movtext 2020-04-10 09:32:13 -07:00
configure configure: add mv30 blockdsp dependency 2020-04-12 09:47:13 +10:00
CONTRIBUTING.md
COPYING.GPLv2
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CREDITS
INSTALL.md INSTALL.md: Fix Markdown formatting 2019-01-31 10:29:16 -09:00
LICENSE.md avfilter/vf_geq: Relicense to LGPL 2019-12-28 11:20:48 +01:00
MAINTAINERS MAINTAINERS: add my gpg fingerprint 2020-03-23 23:37:19 +01:00
Makefile Makefile: Delete more created files when running "make distclean". 2020-03-11 11:43:01 +01:00
README.md Remove the ffserver program 2018-01-06 18:31:37 +00:00
RELEASE RELEASE: Update value for post 4.2 branch 2019-07-21 18:37:32 +02:00

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.