675fa33a95c37cf797f1d579457e6ed7e342cd4e
[deb_ffmpeg.git] / fft_init.c
1 /*
2 * FFT/IFFT transforms
3 * AltiVec-enabled
4 * Copyright (c) 2009 Loren Merritt
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 "config.h"
24 #include "libavutil/cpu.h"
25 #include "libavutil/ppc/cpu.h"
26 #include "libavutil/ppc/types_altivec.h"
27 #include "libavutil/ppc/util_altivec.h"
28 #include "libavcodec/fft.h"
29
30 /**
31 * Do a complex FFT with the parameters defined in ff_fft_init().
32 * The input data must be permuted before with s->revtab table.
33 * No 1.0 / sqrt(n) normalization is done.
34 * AltiVec-enabled:
35 * This code assumes that the 'z' pointer is 16 bytes-aligned.
36 * It also assumes all FFTComplex are 8 bytes-aligned pairs of floats.
37 */
38
39 #if HAVE_VSX
40 #include "fft_vsx.h"
41 #else
42 void ff_fft_calc_altivec(FFTContext *s, FFTComplex *z);
43 void ff_fft_calc_interleave_altivec(FFTContext *s, FFTComplex *z);
44 #endif
45
46 #if HAVE_GNU_AS && HAVE_ALTIVEC
47 static void imdct_half_altivec(FFTContext *s, FFTSample *output, const FFTSample *input)
48 {
49 int j, k;
50 int n = 1 << s->mdct_bits;
51 int n4 = n >> 2;
52 int n8 = n >> 3;
53 int n32 = n >> 5;
54 const uint16_t *revtabj = s->revtab;
55 const uint16_t *revtabk = s->revtab+n4;
56 const vec_f *tcos = (const vec_f*)(s->tcos+n8);
57 const vec_f *tsin = (const vec_f*)(s->tsin+n8);
58 const vec_f *pin = (const vec_f*)(input+n4);
59 vec_f *pout = (vec_f*)(output+n4);
60
61 /* pre rotation */
62 k = n32-1;
63 do {
64 vec_f cos,sin,cos0,sin0,cos1,sin1,re,im,r0,i0,r1,i1,a,b,c,d;
65 #define CMULA(p,o0,o1,o2,o3)\
66 a = pin[ k*2+p]; /* { z[k].re, z[k].im, z[k+1].re, z[k+1].im } */\
67 b = pin[-k*2-p-1]; /* { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im } */\
68 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 } */\
69 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 } */\
70 cos = vec_perm(cos0, cos1, vcprm(o0,o1,s##o2,s##o3)); /* { cos[k], cos[k+1], cos[-k-2], cos[-k-1] } */\
71 sin = vec_perm(sin0, sin1, vcprm(o0,o1,s##o2,s##o3));\
72 r##p = im*cos - re*sin;\
73 i##p = re*cos + im*sin;
74 #define STORE2(v,dst)\
75 j = dst;\
76 vec_ste(v, 0, output+j*2);\
77 vec_ste(v, 4, output+j*2);
78 #define STORE8(p)\
79 a = vec_perm(r##p, i##p, vcprm(0,s0,0,s0));\
80 b = vec_perm(r##p, i##p, vcprm(1,s1,1,s1));\
81 c = vec_perm(r##p, i##p, vcprm(2,s2,2,s2));\
82 d = vec_perm(r##p, i##p, vcprm(3,s3,3,s3));\
83 STORE2(a, revtabk[ p*2-4]);\
84 STORE2(b, revtabk[ p*2-3]);\
85 STORE2(c, revtabj[-p*2+2]);\
86 STORE2(d, revtabj[-p*2+3]);
87
88 cos0 = tcos[k];
89 sin0 = tsin[k];
90 cos1 = tcos[-k-1];
91 sin1 = tsin[-k-1];
92 CMULA(0, 0,1,2,3);
93 CMULA(1, 2,3,0,1);
94 STORE8(0);
95 STORE8(1);
96 revtabj += 4;
97 revtabk -= 4;
98 k--;
99 } while(k >= 0);
100
101 #if HAVE_VSX
102 ff_fft_calc_vsx(s, (FFTComplex*)output);
103 #else
104 ff_fft_calc_altivec(s, (FFTComplex*)output);
105 #endif
106
107 /* post rotation + reordering */
108 j = -n32;
109 k = n32-1;
110 do {
111 vec_f cos,sin,re,im,a,b,c,d;
112 #define CMULB(d0,d1,o)\
113 re = pout[o*2];\
114 im = pout[o*2+1];\
115 cos = tcos[o];\
116 sin = tsin[o];\
117 d0 = im*sin - re*cos;\
118 d1 = re*sin + im*cos;
119
120 CMULB(a,b,j);
121 CMULB(c,d,k);
122 pout[2*j] = vec_perm(a, d, vcprm(0,s3,1,s2));
123 pout[2*j+1] = vec_perm(a, d, vcprm(2,s1,3,s0));
124 pout[2*k] = vec_perm(c, b, vcprm(0,s3,1,s2));
125 pout[2*k+1] = vec_perm(c, b, vcprm(2,s1,3,s0));
126 j++;
127 k--;
128 } while(k >= 0);
129 }
130
131 static void imdct_calc_altivec(FFTContext *s, FFTSample *output, const FFTSample *input)
132 {
133 int k;
134 int n = 1 << s->mdct_bits;
135 int n4 = n >> 2;
136 int n16 = n >> 4;
137 vec_u32 sign = {1U<<31,1U<<31,1U<<31,1U<<31};
138 vec_u32 *p0 = (vec_u32*)(output+n4);
139 vec_u32 *p1 = (vec_u32*)(output+n4*3);
140
141 imdct_half_altivec(s, output + n4, input);
142
143 for (k = 0; k < n16; k++) {
144 vec_u32 a = p0[k] ^ sign;
145 vec_u32 b = p1[-k-1];
146 p0[-k-1] = vec_perm(a, a, vcprm(3,2,1,0));
147 p1[k] = vec_perm(b, b, vcprm(3,2,1,0));
148 }
149 }
150 #endif /* HAVE_GNU_AS && HAVE_ALTIVEC */
151
152 av_cold void ff_fft_init_ppc(FFTContext *s)
153 {
154 #if HAVE_GNU_AS && HAVE_ALTIVEC
155 if (!PPC_ALTIVEC(av_get_cpu_flags()))
156 return;
157
158 #if HAVE_VSX
159 s->fft_calc = ff_fft_calc_interleave_vsx;
160 #else
161 s->fft_calc = ff_fft_calc_interleave_altivec;
162 #endif
163 if (s->mdct_bits >= 5) {
164 s->imdct_calc = imdct_calc_altivec;
165 s->imdct_half = imdct_half_altivec;
166 }
167 #endif /* HAVE_GNU_AS && HAVE_ALTIVEC */
168 }