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06754f7bbf
The callers of the ff_merge_*() functions fall into two categories with quite different needs: One caller is can_merge_formats() which only wants to test for mergeability without it merging anything. In order to do so, it duplicates the lists it intends to test and resets their owners so that they are not modified by ff_merge_*(). It also means that it needs to receive the merged list (and not only an int containing whether the lists are mergeable) to properly free it. The other callers want the lists to be actually merged. But given the fact that ff_merge_*() automatically updates the owners of the lists, they only want the information whether the merge succeeded or not; they don't want a link to the new list. Therefore this commit splits these functions in two: ff_merge_*() for the latter callers and ff_can_merge_*() for the former. ff_merge_*() doesn't need to return a pointer to the combined list at all and hence these functions have been modified to return an int, which allows to distinguish between incompability and memory allocation failures. ff_can_merge_*() meanwhile doesn't modify its arguments at all obviating the need for copies. This in turn implies that there is no reason to return a pointer to the new list, as nothing needs to be freed. These functions therefore return an int as well. This allowed to completely remove can_merge_formats() in avfiltergraph.c. Notice that no ff_can_merge_channel_layouts() has been created, because there is currently no caller for this. It could be added if needed. Reviewed-by: Nicolas George <george@nsup.org> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
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.