mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2026-01-03 04:40:37 +01:00
4fdacf4cdb
Prep work for the next commit, which will add a new FFT algorithm which makes the iMDCT over 3x faster than it is currently (standalone, the FFT is with some framesizes over 10x faster). The new FFT algorithm uses the already thouroughly SIMD'd power of two FFT which already has SIMD for AArch64, so users of that platform will still see an improvement. The previous FFT+SIMD was barely 2.5x faster than the C versions on these platforms. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
/*
|
|
* 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
|
|
*/
|
|
|
|
#ifndef AVCODEC_IMDCT15_H
|
|
#define AVCODEC_IMDCT15_H
|
|
|
|
#include <stddef.h>
|
|
|
|
#include "avfft.h"
|
|
|
|
typedef struct IMDCT15Context {
|
|
int fft_n;
|
|
int len2;
|
|
int len4;
|
|
|
|
FFTComplex *tmp;
|
|
|
|
FFTComplex *twiddle_exptab;
|
|
|
|
FFTComplex *exptab[6];
|
|
|
|
/**
|
|
* Calculate the middle half of the iMDCT
|
|
*/
|
|
void (*imdct_half)(struct IMDCT15Context *s, float *dst, const float *src,
|
|
ptrdiff_t src_stride, float scale);
|
|
} IMDCT15Context;
|
|
|
|
/**
|
|
* Init an iMDCT of the length 2 * 15 * (2^N)
|
|
*/
|
|
int ff_imdct15_init(IMDCT15Context **s, int N);
|
|
|
|
/**
|
|
* Free an iMDCT.
|
|
*/
|
|
void ff_imdct15_uninit(IMDCT15Context **s);
|
|
|
|
#endif /* AVCODEC_IMDCT15_H */
|