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The ATRAC9 decoder uses VLCs which are currently initialized with static length tables of type uint8_t and code tables of type uint16_t. Furthermore, in one case the actually desired symbols are in the range -16..15 and in order to achieve this an ad-hoc symbols table of type int16_t is calculated. This commit modifies this process by replacing the codes tables by symbols tables and switching to ff_init_vlc_from_lengths(); the signed symbols are stored in the table after having been shifted by 16 to fit into an uint8_t and are shifted back when the VLC is created. This makes all symbols fit into an uint8_t, saving space. Furthermore, the earlier tables had holes in them (entries with length zero that were inserted because the actually used symbols were not contiguous); these holes are unnecessary in the new approach, leading to further saving. Finally, given that now both lengths as well as symbols are of the same type, they can be combined; this saves a pointer for each VLC. 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.