b80e43bf07
Motivated by a desire to use vf_libplacebo as a GPU-accelerated cropping/padding/zooming filter. This commit adds support for setting the `input/target.crop` fields as dynamic expressions. Re-use the same generic variables available to other scale and crop type filters, and also add some more that we can afford as a result of being able to set these properties dynamically. It's worth pointing out that `out_t/ot` is currently redundant with `in_t/t` since it will always contain the same PTS values, but I plan on changing this in the near future. I decided to also expose `crop_w/crop_h` and `pos_w/pos_h` as variables in the expression parser itself, since this enables the fairly common use case of determining dimensions first and then placing the image appropriately, such as is done in the default behavior (which centers the cropped/placed region by default).
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 means to alter decoded audio and video through a directed graph of connected 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.