1 /*
2 * SIMD optimized non-power-of-two MDCT functions
3 *
4 * Copyright (C) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include <string.h>
24
25 #include "config.h"
26
27 #include "libavutil/attributes.h"
28 #include "libavutil/x86/cpu.h"
29 #include "libavcodec/mdct15.h"
30
31 void ff_mdct15_postreindex_sse3(FFTComplex *out, FFTComplex *in, FFTComplex *exp, int *lut, ptrdiff_t len8);
32 void ff_mdct15_postreindex_avx2(FFTComplex *out, FFTComplex *in, FFTComplex *exp, int *lut, ptrdiff_t len8);
33
34 void ff_fft15_avx(FFTComplex *out, FFTComplex *in, FFTComplex *exptab, ptrdiff_t stride);
35
perm_twiddles(MDCT15Context *s)36 static void perm_twiddles(MDCT15Context *s)
37 {
38 int k;
39 FFTComplex tmp[30];
40
41 /* 5-point FFT twiddles */
42 s->exptab[60].re = s->exptab[60].im = s->exptab[19].re;
43 s->exptab[61].re = s->exptab[61].im = s->exptab[19].im;
44 s->exptab[62].re = s->exptab[62].im = s->exptab[20].re;
45 s->exptab[63].re = s->exptab[63].im = s->exptab[20].im;
46
47 /* 15-point FFT twiddles */
48 for (k = 0; k < 5; k++) {
49 tmp[6*k + 0] = s->exptab[k + 0];
50 tmp[6*k + 2] = s->exptab[k + 5];
51 tmp[6*k + 4] = s->exptab[k + 10];
52
53 tmp[6*k + 1] = s->exptab[2 * (k + 0)];
54 tmp[6*k + 3] = s->exptab[2 * (k + 5)];
55 tmp[6*k + 5] = s->exptab[2 * k + 5 ];
56 }
57
58 for (k = 0; k < 6; k++) {
59 FFTComplex ac_exp[] = {
60 { tmp[6*1 + k].re, tmp[6*1 + k].re },
61 { tmp[6*2 + k].re, tmp[6*2 + k].re },
62 { tmp[6*3 + k].re, tmp[6*3 + k].re },
63 { tmp[6*4 + k].re, tmp[6*4 + k].re },
64 { tmp[6*1 + k].im, -tmp[6*1 + k].im },
65 { tmp[6*2 + k].im, -tmp[6*2 + k].im },
66 { tmp[6*3 + k].im, -tmp[6*3 + k].im },
67 { tmp[6*4 + k].im, -tmp[6*4 + k].im },
68 };
69 memcpy(s->exptab + 8*k, ac_exp, 8*sizeof(FFTComplex));
70 }
71
72 /* Specialcase when k = 0 */
73 for (k = 0; k < 3; k++) {
74 FFTComplex dc_exp[] = {
75 { tmp[2*k + 0].re, -tmp[2*k + 0].im },
76 { tmp[2*k + 0].im, tmp[2*k + 0].re },
77 { tmp[2*k + 1].re, -tmp[2*k + 1].im },
78 { tmp[2*k + 1].im, tmp[2*k + 1].re },
79 };
80 memcpy(s->exptab + 8*6 + 4*k, dc_exp, 4*sizeof(FFTComplex));
81 }
82 }
83
ff_mdct15_init_x86(MDCT15Context *s)84 av_cold void ff_mdct15_init_x86(MDCT15Context *s)
85 {
86 int adjust_twiddles = 0;
87 int cpu_flags = av_get_cpu_flags();
88
89 if (EXTERNAL_SSE3(cpu_flags))
90 s->postreindex = ff_mdct15_postreindex_sse3;
91
92 #if ARCH_X86_64
93 if (EXTERNAL_AVX(cpu_flags)) {
94 s->fft15 = ff_fft15_avx;
95 adjust_twiddles = 1;
96 }
97
98 if (EXTERNAL_AVX2_FAST(cpu_flags))
99 s->postreindex = ff_mdct15_postreindex_avx2;
100 #endif
101
102 if (adjust_twiddles)
103 perm_twiddles(s);
104 }
105