The purpose of this project is to provide a permissively licenced interface to various C libraries which calculate Discrete Fourier Transforms.
In an ideal world one would choose their favorite FFT library and use it for every project they ever work on. Unfortunately we live in a work of conflicting software licences and unsupported platforms, so at some point most of us will have to stray from our preferred implementations. Providing a uniform interface to as many libraries as possible should help to ease this pain.
ATFFT also provides it own FFT implementation. While this is not optimised to be anywhere near as fast as some of the wrapped libraries, the code is written to be as clear as possible.
Here is some useful information about the libraries usable via the atfft interface:
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- Swift as the wind!
- GPL Licenced.
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- Ultra-optimised black box.
- Intel processors only.
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- A slightly different ultra-optimised black box.
- Intel processors only.
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- Uses all sorts of C++ template magic to specialise DFTs of short lengths.
- GPL Licenced.
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- Nicely speedy.
- Signal lengths of 2^n only.
- Single precision only.
- Only builds on 64bit machines.
- BSD Licenced.
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- Nice and simple (one source file).
- Signal lengths of 2^n only.
- Double precision only.
- Very permissive licence.
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- Part of a much larger library of numerical goodies.
- Double precision only.
- GPL Licenced.
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- Simple, as the name might suggest.
- BSD Licenced.
- Real transforms only support even lengths.
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- Part of libavcodec.
- Signal lengths of 2^n only.
- Single precision only.
- LGPL or GPL Licenced depending on how it's built.
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- Apple only.
- Single and double precision only (no long doubles).
- Signal lengths of 2^n (and some multiples thereof) only.
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- Single precision only.
- Transform length must be multiple of 32 (16 for complex transforms.)
- BDS-like licence.
Copyright (c) 2021 Sean Enderby sean.enderby@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.