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idctdsp.c
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1 /*
2  * Copyright (c) 2001 Michel Lespinasse
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /* NOTE: This code is based on GPL code from the libmpeg2 project. The
22  * author, Michel Lespinasses, has given explicit permission to release
23  * under LGPL as part of FFmpeg.
24  *
25  * FFmpeg integration by Dieter Shirley
26  *
27  * This file is a direct copy of the AltiVec IDCT module from the libmpeg2
28  * project. I've deleted all of the libmpeg2-specific code, renamed the
29  * functions and reordered the function parameters. The only change to the
30  * IDCT function itself was to factor out the partial transposition, and to
31  * perform a full transpose at the end of the function. */
32 
33 #include <stdlib.h>
34 #include <string.h>
35 #include "config.h"
36 #if HAVE_ALTIVEC_H
37 #include <altivec.h>
38 #endif
39 
40 #include "libavutil/attributes.h"
41 #include "libavutil/cpu.h"
42 #include "libavutil/ppc/cpu.h"
43 #include "libavutil/ppc/types_altivec.h"
44 #include "libavcodec/idctdsp.h"
45 
46 #if HAVE_ALTIVEC
47 
48 #define IDCT_HALF \
49  /* 1st stage */ \
50  t1 = vec_mradds(a1, vx7, vx1); \
51  t8 = vec_mradds(a1, vx1, vec_subs(zero, vx7)); \
52  t7 = vec_mradds(a2, vx5, vx3); \
53  t3 = vec_mradds(ma2, vx3, vx5); \
54  \
55  /* 2nd stage */ \
56  t5 = vec_adds(vx0, vx4); \
57  t0 = vec_subs(vx0, vx4); \
58  t2 = vec_mradds(a0, vx6, vx2); \
59  t4 = vec_mradds(a0, vx2, vec_subs(zero, vx6)); \
60  t6 = vec_adds(t8, t3); \
61  t3 = vec_subs(t8, t3); \
62  t8 = vec_subs(t1, t7); \
63  t1 = vec_adds(t1, t7); \
64  \
65  /* 3rd stage */ \
66  t7 = vec_adds(t5, t2); \
67  t2 = vec_subs(t5, t2); \
68  t5 = vec_adds(t0, t4); \
69  t0 = vec_subs(t0, t4); \
70  t4 = vec_subs(t8, t3); \
71  t3 = vec_adds(t8, t3); \
72  \
73  /* 4th stage */ \
74  vy0 = vec_adds(t7, t1); \
75  vy7 = vec_subs(t7, t1); \
76  vy1 = vec_mradds(c4, t3, t5); \
77  vy6 = vec_mradds(mc4, t3, t5); \
78  vy2 = vec_mradds(c4, t4, t0); \
79  vy5 = vec_mradds(mc4, t4, t0); \
80  vy3 = vec_adds(t2, t6); \
81  vy4 = vec_subs(t2, t6)
82 
83 #define IDCT \
84  vec_s16 vy0, vy1, vy2, vy3, vy4, vy5, vy6, vy7; \
85  vec_s16 t0, t1, t2, t3, t4, t5, t6, t7, t8; \
86  \
87  vec_s16 c4 = vec_splat(constants[0], 0); \
88  vec_s16 a0 = vec_splat(constants[0], 1); \
89  vec_s16 a1 = vec_splat(constants[0], 2); \
90  vec_s16 a2 = vec_splat(constants[0], 3); \
91  vec_s16 mc4 = vec_splat(constants[0], 4); \
92  vec_s16 ma2 = vec_splat(constants[0], 5); \
93  vec_s16 bias = (vec_s16) vec_splat((vec_s32) constants[0], 3); \
94  \
95  vec_s16 zero = vec_splat_s16(0); \
96  vec_u16 shift = vec_splat_u16(4); \
97  \
98  vec_s16 vx0 = vec_mradds(vec_sl(block[0], shift), constants[1], zero); \
99  vec_s16 vx1 = vec_mradds(vec_sl(block[1], shift), constants[2], zero); \
100  vec_s16 vx2 = vec_mradds(vec_sl(block[2], shift), constants[3], zero); \
101  vec_s16 vx3 = vec_mradds(vec_sl(block[3], shift), constants[4], zero); \
102  vec_s16 vx4 = vec_mradds(vec_sl(block[4], shift), constants[1], zero); \
103  vec_s16 vx5 = vec_mradds(vec_sl(block[5], shift), constants[4], zero); \
104  vec_s16 vx6 = vec_mradds(vec_sl(block[6], shift), constants[3], zero); \
105  vec_s16 vx7 = vec_mradds(vec_sl(block[7], shift), constants[2], zero); \
106  \
107  IDCT_HALF; \
108  \
109  vx0 = vec_mergeh(vy0, vy4); \
110  vx1 = vec_mergel(vy0, vy4); \
111  vx2 = vec_mergeh(vy1, vy5); \
112  vx3 = vec_mergel(vy1, vy5); \
113  vx4 = vec_mergeh(vy2, vy6); \
114  vx5 = vec_mergel(vy2, vy6); \
115  vx6 = vec_mergeh(vy3, vy7); \
116  vx7 = vec_mergel(vy3, vy7); \
117  \
118  vy0 = vec_mergeh(vx0, vx4); \
119  vy1 = vec_mergel(vx0, vx4); \
120  vy2 = vec_mergeh(vx1, vx5); \
121  vy3 = vec_mergel(vx1, vx5); \
122  vy4 = vec_mergeh(vx2, vx6); \
123  vy5 = vec_mergel(vx2, vx6); \
124  vy6 = vec_mergeh(vx3, vx7); \
125  vy7 = vec_mergel(vx3, vx7); \
126  \
127  vx0 = vec_adds(vec_mergeh(vy0, vy4), bias); \
128  vx1 = vec_mergel(vy0, vy4); \
129  vx2 = vec_mergeh(vy1, vy5); \
130  vx3 = vec_mergel(vy1, vy5); \
131  vx4 = vec_mergeh(vy2, vy6); \
132  vx5 = vec_mergel(vy2, vy6); \
133  vx6 = vec_mergeh(vy3, vy7); \
134  vx7 = vec_mergel(vy3, vy7); \
135  \
136  IDCT_HALF; \
137  \
138  shift = vec_splat_u16(6); \
139  vx0 = vec_sra(vy0, shift); \
140  vx1 = vec_sra(vy1, shift); \
141  vx2 = vec_sra(vy2, shift); \
142  vx3 = vec_sra(vy3, shift); \
143  vx4 = vec_sra(vy4, shift); \
144  vx5 = vec_sra(vy5, shift); \
145  vx6 = vec_sra(vy6, shift); \
146  vx7 = vec_sra(vy7, shift)
147 
148 static const vec_s16 constants[5] = {
149  { 23170, 13573, 6518, 21895, -23170, -21895, 32, 31 },
150  { 16384, 22725, 21407, 19266, 16384, 19266, 21407, 22725 },
151  { 22725, 31521, 29692, 26722, 22725, 26722, 29692, 31521 },
152  { 21407, 29692, 27969, 25172, 21407, 25172, 27969, 29692 },
153  { 19266, 26722, 25172, 22654, 19266, 22654, 25172, 26722 }
154 };
155 
156 static void idct_altivec(int16_t *blk)
157 {
158  vec_s16 *block = (vec_s16 *) blk;
159 
160  IDCT;
161 
162  block[0] = vx0;
163  block[1] = vx1;
164  block[2] = vx2;
165  block[3] = vx3;
166  block[4] = vx4;
167  block[5] = vx5;
168  block[6] = vx6;
169  block[7] = vx7;
170 }
171 
172 static void idct_put_altivec(uint8_t *dest, int stride, int16_t *blk)
173 {
174  vec_s16 *block = (vec_s16 *) blk;
175  vec_u8 tmp;
176 
177  IDCT;
178 
179 #define COPY(dest, src) \
180  tmp = vec_packsu(src, src); \
181  vec_ste((vec_u32) tmp, 0, (unsigned int *) dest); \
182  vec_ste((vec_u32) tmp, 4, (unsigned int *) dest)
183 
184  COPY(dest, vx0);
185  dest += stride;
186  COPY(dest, vx1);
187  dest += stride;
188  COPY(dest, vx2);
189  dest += stride;
190  COPY(dest, vx3);
191  dest += stride;
192  COPY(dest, vx4);
193  dest += stride;
194  COPY(dest, vx5);
195  dest += stride;
196  COPY(dest, vx6);
197  dest += stride;
198  COPY(dest, vx7);
199 }
200 
201 static void idct_add_altivec(uint8_t *dest, int stride, int16_t *blk)
202 {
203  vec_s16 *block = (vec_s16 *) blk;
204  vec_u8 tmp;
205  vec_s16 tmp2, tmp3;
206  vec_u8 perm0;
207  vec_u8 perm1;
208  vec_u8 p0, p1, p;
209 
210  IDCT;
211 
212 #if HAVE_BIGENDIAN
213  p0 = vec_lvsl(0, dest);
214  p1 = vec_lvsl(stride, dest);
215  p = vec_splat_u8(-1);
216  perm0 = vec_mergeh(p, p0);
217  perm1 = vec_mergeh(p, p1);
218 #endif
219 
220 #if HAVE_BIGENDIAN
221 #define GET_TMP2(dest, prm) \
222  tmp = vec_ld(0, dest); \
223  tmp2 = (vec_s16) vec_perm(tmp, (vec_u8) zero, prm);
224 #else
225 #define GET_TMP2(dest, prm) \
226  tmp = vec_vsx_ld(0, dest); \
227  tmp2 = (vec_s16) vec_mergeh(tmp, (vec_u8) zero)
228 #endif
229 
230 #define ADD(dest, src, perm) \
231  GET_TMP2(dest, perm); \
232  tmp3 = vec_adds(tmp2, src); \
233  tmp = vec_packsu(tmp3, tmp3); \
234  vec_ste((vec_u32) tmp, 0, (unsigned int *) dest); \
235  vec_ste((vec_u32) tmp, 4, (unsigned int *) dest)
236 
237  ADD(dest, vx0, perm0);
238  dest += stride;
239  ADD(dest, vx1, perm1);
240  dest += stride;
241  ADD(dest, vx2, perm0);
242  dest += stride;
243  ADD(dest, vx3, perm1);
244  dest += stride;
245  ADD(dest, vx4, perm0);
246  dest += stride;
247  ADD(dest, vx5, perm1);
248  dest += stride;
249  ADD(dest, vx6, perm0);
250  dest += stride;
251  ADD(dest, vx7, perm1);
252 }
253 
254 #endif /* HAVE_ALTIVEC */
255 
256 av_cold void ff_idctdsp_init_ppc(IDCTDSPContext *c, AVCodecContext *avctx,
257  unsigned high_bit_depth)
258 {
259 #if HAVE_ALTIVEC
260  if (!PPC_ALTIVEC(av_get_cpu_flags()))
261  return;
262 
263  if (!high_bit_depth && avctx->lowres == 0) {
264  if ((avctx->idct_algo == FF_IDCT_AUTO && !(avctx->flags & CODEC_FLAG_BITEXACT)) ||
265  (avctx->idct_algo == FF_IDCT_ALTIVEC)) {
266  c->idct = idct_altivec;
267  c->idct_add = idct_add_altivec;
268  c->idct_put = idct_put_altivec;
269  c->perm_type = FF_IDCT_PERM_TRANSPOSE;
270  }
271  }
272 #endif /* HAVE_ALTIVEC */
273 }
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