518bbe9eac
According to the H.264 specifications, the only NAL units that need to have four byte startcodes in H.264 Annex B format are SPS/PPS units and units that start a new access unit. Before af7e953a, the first of these conditions wasn't upheld as already existing in-band parameter sets would not automatically be written with a four byte startcode, but only when they already were at the beginning of their input packets. But it made four byte startcodes be used too often as every unit that is written together with a parameter set that is inserted from extradata received a four byte startcode although a three byte start code would suffice unless the unit itself were a parameter set. FATE has been updated to reflect the changes. Although the patch leaves the extradata unchanged, the size of the extradata according to the FATE reports changes. This is due to a quirk in ff_h2645_packet_split which is used by extract_extradata: If the input is Annex B, the first zero of a four byte startcode is considered a part of the last unit (if any). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodecprovides implementation of a wider range of codecs.libavformatimplements streaming protocols, container formats and basic I/O access.libavutilincludes hashers, decompressors and miscellaneous utility functions.libavfilterprovides a mean to alter decoded Audio and Video through chain of filters.libavdeviceprovides an abstraction to access capture and playback devices.libswresampleimplements audio mixing and resampling routines.libswscaleimplements 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,ismindexandqt-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.