bc109a53c7
These tables are only used by encoders and only for the current picture; ergo they need not be put into the picture at all, but rather into the encoder's context. They also don't need to be refcounted, because there is only one owner. In contrast to this, the earlier code refcounts them which incurs unnecessary overhead. These references are not unreferenced in ff_mpeg_unref_picture() (they are kept in order to have something like a buffer pool), so that several buffers are kept at the same time, although only one is needed, thereby wasting memory. The code also propagates references to other pictures not part of the pictures array (namely the copy of the current/next/last picture in the MpegEncContext which get references of their own). These references are not unreferenced in ff_mpeg_unref_picture() (the buffers are probably kept in order to have something like a pool), yet if the current picture is a B-frame, it gets unreferenced at the end of ff_mpv_encode_picture() and its slot in the picture array will therefore be reused the next time; but the copy of the current picture also still has its references and therefore these buffers will be made duplicated in order to make them writable in the next call to ff_mpv_encode_picture(). This is of course unnecessary. Finally, ff_find_unused_picture() is supposed to just return any unused picture and the code is supposed to work with it; yet for the vsynth*-mpeg4-adap tests the result depends upon the content of these buffers; given that this patchset changes the content of these buffers (the initial content is now the state of these buffers after encoding the last frame; before this patch the buffers used came from the last picture that occupied the same slot in the picture array) their ref-files needed to be changed. This points to a bug somewhere (if one removes the initialization, one gets uninitialized reads in adaptive_quantization in ratecontrol.c). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> |
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| compat | ||
| doc | ||
| ffbuild | ||
| fftools | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavutil | ||
| libpostproc | ||
| libswresample | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .travis.yml | ||
| Changelog | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| INSTALL.md | ||
| LICENSE.md | ||
| MAINTAINERS | ||
| Makefile | ||
| README.md | ||
| RELEASE | ||
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.