00117e28c1
SMPTE 12M timecode can only count frames up to 39, because the tens-of-frames value is stored in 2 bit. In order to resolve this 50/60 fps SMPTE timecode is using the field bit (which is the same bit as the phase correction bit) to signal the least significant bit of a 50/60 fps timecode. See SMPTE ST 12-1:2014 section 12.1. Therefore we slightly change the format of the return value of av_timecode_get_smpte_from_framenum and AV_FRAME_DATA_S12M_TIMECODE and start using the previously unused Phase Correction bit as Field bit. (As the SMPTE standard suggests) We add 50/60 fps support to av_timecode_get_smpte_from_framenum by calling the recently added av_timecode_get_smpte function in it which already handles this properly. This change affects the decklink indev and the DV and MXF muxers. MXF has no fate test for 50/60fps content, DV does, therefore the changes. MediaInfo (a recent version) confirms that half-frame timecode must be inserted to DV. MXFInspect confirms valid timecode insertion to the System Item of MXF files. For MXF, also see EBU R122. Note that for DV the field flag is not used because in the HDV specs (SMPTE 370M) it is still defined as biphase mark polarity correction flag. So it should not matter that the DV muxer overrides the field bit. Signed-off-by: Marton Balint <cus@passwd.hu>
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.