1/* 2 * FFT/IFFT transforms 3 * AltiVec-enabled 4 * Copyright (c) 2009 Loren Merritt 5 * 6 * This file is part of Libav. 7 * 8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22#include "libavcodec/fft.h" 23#include "util_altivec.h" 24#include "types_altivec.h" 25 26/** 27 * Do a complex FFT with the parameters defined in ff_fft_init(). The 28 * input data must be permuted before with s->revtab table. No 29 * 1.0/sqrt(n) normalization is done. 30 * AltiVec-enabled 31 * This code assumes that the 'z' pointer is 16 bytes-aligned 32 * It also assumes all FFTComplex are 8 bytes-aligned pair of float 33 */ 34 35void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z); 36void ff_fft_calc_interleave_altivec(FFTContext *s, FFTComplex *z); 37 38#if HAVE_GNU_AS 39static void ff_imdct_half_altivec(FFTContext *s, FFTSample *output, const FFTSample *input) 40{ 41 int j, k; 42 int n = 1 << s->mdct_bits; 43 int n4 = n >> 2; 44 int n8 = n >> 3; 45 int n32 = n >> 5; 46 const uint16_t *revtabj = s->revtab; 47 const uint16_t *revtabk = s->revtab+n4; 48 const vec_f *tcos = (const vec_f*)(s->tcos+n8); 49 const vec_f *tsin = (const vec_f*)(s->tsin+n8); 50 const vec_f *pin = (const vec_f*)(input+n4); 51 vec_f *pout = (vec_f*)(output+n4); 52 53 /* pre rotation */ 54 k = n32-1; 55 do { 56 vec_f cos,sin,cos0,sin0,cos1,sin1,re,im,r0,i0,r1,i1,a,b,c,d; 57#define CMULA(p,o0,o1,o2,o3)\ 58 a = pin[ k*2+p]; /* { z[k].re, z[k].im, z[k+1].re, z[k+1].im } */\ 59 b = pin[-k*2-p-1]; /* { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im } */\ 60 re = vec_perm(a, b, vcprm(0,2,s0,s2)); /* { z[k].re, z[k+1].re, z[-k-2].re, z[-k-1].re } */\ 61 im = vec_perm(a, b, vcprm(s3,s1,3,1)); /* { z[-k-1].im, z[-k-2].im, z[k+1].im, z[k].im } */\ 62 cos = vec_perm(cos0, cos1, vcprm(o0,o1,s##o2,s##o3)); /* { cos[k], cos[k+1], cos[-k-2], cos[-k-1] } */\ 63 sin = vec_perm(sin0, sin1, vcprm(o0,o1,s##o2,s##o3));\ 64 r##p = im*cos - re*sin;\ 65 i##p = re*cos + im*sin; 66#define STORE2(v,dst)\ 67 j = dst;\ 68 vec_ste(v, 0, output+j*2);\ 69 vec_ste(v, 4, output+j*2); 70#define STORE8(p)\ 71 a = vec_perm(r##p, i##p, vcprm(0,s0,0,s0));\ 72 b = vec_perm(r##p, i##p, vcprm(1,s1,1,s1));\ 73 c = vec_perm(r##p, i##p, vcprm(2,s2,2,s2));\ 74 d = vec_perm(r##p, i##p, vcprm(3,s3,3,s3));\ 75 STORE2(a, revtabk[ p*2-4]);\ 76 STORE2(b, revtabk[ p*2-3]);\ 77 STORE2(c, revtabj[-p*2+2]);\ 78 STORE2(d, revtabj[-p*2+3]); 79 80 cos0 = tcos[k]; 81 sin0 = tsin[k]; 82 cos1 = tcos[-k-1]; 83 sin1 = tsin[-k-1]; 84 CMULA(0, 0,1,2,3); 85 CMULA(1, 2,3,0,1); 86 STORE8(0); 87 STORE8(1); 88 revtabj += 4; 89 revtabk -= 4; 90 k--; 91 } while(k >= 0); 92 93 ff_fft_calc_altivec(s, (FFTComplex*)output); 94 95 /* post rotation + reordering */ 96 j = -n32; 97 k = n32-1; 98 do { 99 vec_f cos,sin,re,im,a,b,c,d; 100#define CMULB(d0,d1,o)\ 101 re = pout[o*2];\ 102 im = pout[o*2+1];\ 103 cos = tcos[o];\ 104 sin = tsin[o];\ 105 d0 = im*sin - re*cos;\ 106 d1 = re*sin + im*cos; 107 108 CMULB(a,b,j); 109 CMULB(c,d,k); 110 pout[2*j] = vec_perm(a, d, vcprm(0,s3,1,s2)); 111 pout[2*j+1] = vec_perm(a, d, vcprm(2,s1,3,s0)); 112 pout[2*k] = vec_perm(c, b, vcprm(0,s3,1,s2)); 113 pout[2*k+1] = vec_perm(c, b, vcprm(2,s1,3,s0)); 114 j++; 115 k--; 116 } while(k >= 0); 117} 118 119static void ff_imdct_calc_altivec(FFTContext *s, FFTSample *output, const FFTSample *input) 120{ 121 int k; 122 int n = 1 << s->mdct_bits; 123 int n4 = n >> 2; 124 int n16 = n >> 4; 125 vec_u32 sign = {1U<<31,1U<<31,1U<<31,1U<<31}; 126 vec_u32 *p0 = (vec_u32*)(output+n4); 127 vec_u32 *p1 = (vec_u32*)(output+n4*3); 128 129 ff_imdct_half_altivec(s, output+n4, input); 130 131 for (k = 0; k < n16; k++) { 132 vec_u32 a = p0[k] ^ sign; 133 vec_u32 b = p1[-k-1]; 134 p0[-k-1] = vec_perm(a, a, vcprm(3,2,1,0)); 135 p1[k] = vec_perm(b, b, vcprm(3,2,1,0)); 136 } 137} 138#endif /* HAVE_GNU_AS */ 139 140av_cold void ff_fft_init_altivec(FFTContext *s) 141{ 142#if HAVE_GNU_AS 143 s->fft_calc = ff_fft_calc_interleave_altivec; 144 if (s->mdct_bits >= 5) { 145 s->imdct_calc = ff_imdct_calc_altivec; 146 s->imdct_half = ff_imdct_half_altivec; 147 } 148#endif 149} 150