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Marton Balint
5df901ffa5
avutil/timestamp: introduce av_ts_make_time_string2 for better precision
av_ts_make_time_string() used "%.6g" format, but this format was losing precision even when the timestamp to be printed was not that large. For example for 3 hours (10800) seconds, only 1 decimal digit was printed, which made this format inaccurate when it was used in e.g. the silencedetect filter. Other detection filters printing timestamps had similar issues. Also time base parameter of the function was *AVRational instead of AVRational. Resolve these problems by introducing a new function, av_ts_make_time_string2(). We change the used format to "%.*f", use a precision of 6, except when printing values near 0, in which case we calculate the precision dynamically to aim for a similar precision in normal form as with %.6g. No longer using scientific representation can make parsing the timestamp easier for the users, we can safely do this because the theoretical maximum of INT64_MAX*INT32_MAX still fits into the string buffer in normal form. We somewhat imitate %g by trimming ending zeroes and the potential decimal point characters. In order not to trim "inf" as well, we assume that the decimal point string does not contain the letter "f". Note that depending on printf %f implementation, we might trim "infinity" to "inf". Thanks for Allan Cady for bringing up this issue. Signed-off-by: Marton Balint <cus@passwd.hu>
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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 means to alter decoded audio and video through a directed graph of connected 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%