ffmpeg/libavutil/version.h
Lynne 5ca40d6d94
lavu/tx: support in-place FFT transforms
This commit adds support for in-place FFT transforms. Since our
internal transforms were all in-place anyway, this only changes
the permutation on the input.

Unfortunately, research papers were of no help here. All focused
on dry hardware implementations, where permutes are free, or on
software implementations where binary bloat is of no concern so
storing dozen times the transforms for each permutation and version
is not considered bad practice.
Still, for a pure C implementation, it's only around 28% slower
than the multi-megabyte FFTW3 in unaligned mode.

Unlike a closed permutation like with PFA, split-radix FFT bit-reversals
contain multiple NOPs, multiple simple swaps, and a few chained swaps,
so regular single-loop single-state permute loops were not possible.
Instead, we filter out parts of the input indices which are redundant.
This allows for a single branch, and with some clever AVX512 asm,
could possibly be SIMD'd without refactoring.

The inplace_idx array is guaranteed to never be larger than the
revtab array, and in practice only requires around log2(len) entries.

The power-of-two MDCTs can be done in-place as well. And it's
possible to eliminate a copy in the compound MDCTs too, however
it'll be slower than doing them out of place, and we'd need to dirty
the input array.
2021-02-21 17:05:16 +01:00

148 lines
4.9 KiB
C

/*
* copyright (c) 2003 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @ingroup lavu
* Libavutil version macros
*/
#ifndef AVUTIL_VERSION_H
#define AVUTIL_VERSION_H
#include "macros.h"
/**
* @addtogroup version_utils
*
* Useful to check and match library version in order to maintain
* backward compatibility.
*
* The FFmpeg libraries follow a versioning sheme very similar to
* Semantic Versioning (http://semver.org/)
* The difference is that the component called PATCH is called MICRO in FFmpeg
* and its value is reset to 100 instead of 0 to keep it above or equal to 100.
* Also we do not increase MICRO for every bugfix or change in git master.
*
* Prior to FFmpeg 3.2 point releases did not change any lib version number to
* avoid aliassing different git master checkouts.
* Starting with FFmpeg 3.2, the released library versions will occupy
* a separate MAJOR.MINOR that is not used on the master development branch.
* That is if we branch a release of master 55.10.123 we will bump to 55.11.100
* for the release and master will continue at 55.12.100 after it. Each new
* point release will then bump the MICRO improving the usefulness of the lib
* versions.
*
* @{
*/
#define AV_VERSION_INT(a, b, c) ((a)<<16 | (b)<<8 | (c))
#define AV_VERSION_DOT(a, b, c) a ##.## b ##.## c
#define AV_VERSION(a, b, c) AV_VERSION_DOT(a, b, c)
/**
* Extract version components from the full ::AV_VERSION_INT int as returned
* by functions like ::avformat_version() and ::avcodec_version()
*/
#define AV_VERSION_MAJOR(a) ((a) >> 16)
#define AV_VERSION_MINOR(a) (((a) & 0x00FF00) >> 8)
#define AV_VERSION_MICRO(a) ((a) & 0xFF)
/**
* @}
*/
/**
* @defgroup lavu_ver Version and Build diagnostics
*
* Macros and function useful to check at compiletime and at runtime
* which version of libavutil is in use.
*
* @{
*/
#define LIBAVUTIL_VERSION_MAJOR 56
#define LIBAVUTIL_VERSION_MINOR 66
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
LIBAVUTIL_VERSION_MINOR, \
LIBAVUTIL_VERSION_MICRO)
#define LIBAVUTIL_VERSION AV_VERSION(LIBAVUTIL_VERSION_MAJOR, \
LIBAVUTIL_VERSION_MINOR, \
LIBAVUTIL_VERSION_MICRO)
#define LIBAVUTIL_BUILD LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_IDENT "Lavu" AV_STRINGIFY(LIBAVUTIL_VERSION)
/**
* @defgroup lavu_depr_guards Deprecation Guards
* FF_API_* defines may be placed below to indicate public API that will be
* dropped at a future version bump. The defines themselves are not part of
* the public API and may change, break or disappear at any time.
*
* @note, when bumping the major version it is recommended to manually
* disable each FF_API_* in its own commit instead of disabling them all
* at once through the bump. This improves the git bisect-ability of the change.
*
* @{
*/
#ifndef FF_API_VAAPI
#define FF_API_VAAPI (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_FRAME_QP
#define FF_API_FRAME_QP (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_PLUS1_MINUS1
#define FF_API_PLUS1_MINUS1 (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_ERROR_FRAME
#define FF_API_ERROR_FRAME (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_PKT_PTS
#define FF_API_PKT_PTS (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_CRYPTO_SIZE_T
#define FF_API_CRYPTO_SIZE_T (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_FRAME_GET_SET
#define FF_API_FRAME_GET_SET (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_PSEUDOPAL
#define FF_API_PSEUDOPAL (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_CHILD_CLASS_NEXT
#define FF_API_CHILD_CLASS_NEXT (LIBAVUTIL_VERSION_MAJOR < 57)
#endif
#ifndef FF_API_D2STR
#define FF_API_D2STR (LIBAVUTIL_VERSION_MAJOR < 58)
#endif
#ifndef FF_API_DECLARE_ALIGNED
#define FF_API_DECLARE_ALIGNED (LIBAVUTIL_VERSION_MAJOR < 58)
#endif
/**
* @}
* @}
*/
#endif /* AVUTIL_VERSION_H */