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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 "config.h"
34 
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "libavutil/attributes.h"
39 #include "libavutil/cpu.h"
40 #include "libavutil/ppc/cpu.h"
41 #include "libavutil/ppc/util_altivec.h"
42 
43 #include "libavcodec/idctdsp.h"
44 
45 #if HAVE_ALTIVEC
46 
47 #define IDCT_HALF                                       \
48     /* 1st stage */                                     \
49     t1 = vec_mradds(a1, vx7, vx1);                      \
50     t8 = vec_mradds(a1, vx1, vec_subs(zero, vx7));      \
51     t7 = vec_mradds(a2, vx5, vx3);                      \
52     t3 = vec_mradds(ma2, vx3, vx5);                     \
53                                                         \
54     /* 2nd stage */                                     \
55     t5 = vec_adds(vx0, vx4);                            \
56     t0 = vec_subs(vx0, vx4);                            \
57     t2 = vec_mradds(a0, vx6, vx2);                      \
58     t4 = vec_mradds(a0, vx2, vec_subs(zero, vx6));      \
59     t6 = vec_adds(t8, t3);                              \
60     t3 = vec_subs(t8, t3);                              \
61     t8 = vec_subs(t1, t7);                              \
62     t1 = vec_adds(t1, t7);                              \
63                                                         \
64     /* 3rd stage */                                     \
65     t7 = vec_adds(t5, t2);                              \
66     t2 = vec_subs(t5, t2);                              \
67     t5 = vec_adds(t0, t4);                              \
68     t0 = vec_subs(t0, t4);                              \
69     t4 = vec_subs(t8, t3);                              \
70     t3 = vec_adds(t8, t3);                              \
71                                                         \
72     /* 4th stage */                                     \
73     vy0 = vec_adds(t7, t1);                             \
74     vy7 = vec_subs(t7, t1);                             \
75     vy1 = vec_mradds(c4, t3, t5);                       \
76     vy6 = vec_mradds(mc4, t3, t5);                      \
77     vy2 = vec_mradds(c4, t4, t0);                       \
78     vy5 = vec_mradds(mc4, t4, t0);                      \
79     vy3 = vec_adds(t2, t6);                             \
80     vy4 = vec_subs(t2, t6)
81 
82 #define IDCT                                                                \
83     vec_s16 vy0, vy1, vy2, vy3, vy4, vy5, vy6, vy7;                         \
84     vec_s16 t0, t1, t2, t3, t4, t5, t6, t7, t8;                             \
85                                                                             \
86     vec_s16 c4   = vec_splat(constants[0], 0);                              \
87     vec_s16 a0   = vec_splat(constants[0], 1);                              \
88     vec_s16 a1   = vec_splat(constants[0], 2);                              \
89     vec_s16 a2   = vec_splat(constants[0], 3);                              \
90     vec_s16 mc4  = vec_splat(constants[0], 4);                              \
91     vec_s16 ma2  = vec_splat(constants[0], 5);                              \
92     vec_s16 bias = (vec_s16) vec_splat((vec_s32) constants[0], 3);          \
93                                                                             \
94     vec_s16 zero  = vec_splat_s16(0);                                       \
95     vec_u16 shift = vec_splat_u16(4);                                       \
96                                                                             \
97     vec_s16 vx0 = vec_mradds(vec_sl(block[0], shift), constants[1], zero);  \
98     vec_s16 vx1 = vec_mradds(vec_sl(block[1], shift), constants[2], zero);  \
99     vec_s16 vx2 = vec_mradds(vec_sl(block[2], shift), constants[3], zero);  \
100     vec_s16 vx3 = vec_mradds(vec_sl(block[3], shift), constants[4], zero);  \
101     vec_s16 vx4 = vec_mradds(vec_sl(block[4], shift), constants[1], zero);  \
102     vec_s16 vx5 = vec_mradds(vec_sl(block[5], shift), constants[4], zero);  \
103     vec_s16 vx6 = vec_mradds(vec_sl(block[6], shift), constants[3], zero);  \
104     vec_s16 vx7 = vec_mradds(vec_sl(block[7], shift), constants[2], zero);  \
105                                                                             \
106     IDCT_HALF;                                                              \
107                                                                             \
108     vx0 = vec_mergeh(vy0, vy4);                                             \
109     vx1 = vec_mergel(vy0, vy4);                                             \
110     vx2 = vec_mergeh(vy1, vy5);                                             \
111     vx3 = vec_mergel(vy1, vy5);                                             \
112     vx4 = vec_mergeh(vy2, vy6);                                             \
113     vx5 = vec_mergel(vy2, vy6);                                             \
114     vx6 = vec_mergeh(vy3, vy7);                                             \
115     vx7 = vec_mergel(vy3, vy7);                                             \
116                                                                             \
117     vy0 = vec_mergeh(vx0, vx4);                                             \
118     vy1 = vec_mergel(vx0, vx4);                                             \
119     vy2 = vec_mergeh(vx1, vx5);                                             \
120     vy3 = vec_mergel(vx1, vx5);                                             \
121     vy4 = vec_mergeh(vx2, vx6);                                             \
122     vy5 = vec_mergel(vx2, vx6);                                             \
123     vy6 = vec_mergeh(vx3, vx7);                                             \
124     vy7 = vec_mergel(vx3, vx7);                                             \
125                                                                             \
126     vx0 = vec_adds(vec_mergeh(vy0, vy4), bias);                             \
127     vx1 = vec_mergel(vy0, vy4);                                             \
128     vx2 = vec_mergeh(vy1, vy5);                                             \
129     vx3 = vec_mergel(vy1, vy5);                                             \
130     vx4 = vec_mergeh(vy2, vy6);                                             \
131     vx5 = vec_mergel(vy2, vy6);                                             \
132     vx6 = vec_mergeh(vy3, vy7);                                             \
133     vx7 = vec_mergel(vy3, vy7);                                             \
134                                                                             \
135     IDCT_HALF;                                                              \
136                                                                             \
137     shift = vec_splat_u16(6);                                               \
138     vx0 = vec_sra(vy0, shift);                                              \
139     vx1 = vec_sra(vy1, shift);                                              \
140     vx2 = vec_sra(vy2, shift);                                              \
141     vx3 = vec_sra(vy3, shift);                                              \
142     vx4 = vec_sra(vy4, shift);                                              \
143     vx5 = vec_sra(vy5, shift);                                              \
144     vx6 = vec_sra(vy6, shift);                                              \
145     vx7 = vec_sra(vy7, shift)
146 
147 static const vec_s16 constants[5] = {
148     { 23170, 13573,  6518, 21895, -23170, -21895,    32,    31 },
149     { 16384, 22725, 21407, 19266,  16384,  19266, 21407, 22725 },
150     { 22725, 31521, 29692, 26722,  22725,  26722, 29692, 31521 },
151     { 21407, 29692, 27969, 25172,  21407,  25172, 27969, 29692 },
152     { 19266, 26722, 25172, 22654,  19266,  22654, 25172, 26722 }
153 };
154 
idct_altivec(int16_t * blk)155 static void idct_altivec(int16_t *blk)
156 {
157     vec_s16 *block = (vec_s16 *) blk;
158 
159     IDCT;
160 
161     block[0] = vx0;
162     block[1] = vx1;
163     block[2] = vx2;
164     block[3] = vx3;
165     block[4] = vx4;
166     block[5] = vx5;
167     block[6] = vx6;
168     block[7] = vx7;
169 }
170 
idct_put_altivec(uint8_t * dest,ptrdiff_t stride,int16_t * blk)171 static void idct_put_altivec(uint8_t *dest, ptrdiff_t stride, int16_t *blk)
172 {
173     vec_s16 *block = (vec_s16 *) blk;
174     vec_u8 tmp;
175 
176     IDCT;
177 
178 #define COPY(dest, src)                                     \
179     tmp = vec_packsu(src, src);                             \
180     vec_ste((vec_u32) tmp, 0, (unsigned int *) dest);       \
181     vec_ste((vec_u32) tmp, 4, (unsigned int *) dest)
182 
183     COPY(dest, vx0);
184     dest += stride;
185     COPY(dest, vx1);
186     dest += stride;
187     COPY(dest, vx2);
188     dest += stride;
189     COPY(dest, vx3);
190     dest += stride;
191     COPY(dest, vx4);
192     dest += stride;
193     COPY(dest, vx5);
194     dest += stride;
195     COPY(dest, vx6);
196     dest += stride;
197     COPY(dest, vx7);
198 }
199 
idct_add_altivec(uint8_t * dest,ptrdiff_t stride,int16_t * blk)200 static void idct_add_altivec(uint8_t *dest, ptrdiff_t stride, int16_t *blk)
201 {
202     vec_s16 *block = (vec_s16 *) blk;
203     vec_u8 tmp;
204     vec_s16 tmp2, tmp3;
205     vec_u8 perm0;
206     vec_u8 perm1;
207     vec_u8 p0, p1, p;
208 
209     IDCT;
210 
211 #if HAVE_BIGENDIAN
212     p0    = vec_lvsl(0, dest);
213     p1    = vec_lvsl(stride, dest);
214     p     = vec_splat_u8(-1);
215     perm0 = vec_mergeh(p, p0);
216     perm1 = vec_mergeh(p, p1);
217 #endif
218 
219 #if HAVE_BIGENDIAN
220 #define GET_TMP2(dest, prm)                                 \
221     tmp  = vec_ld(0, dest);                                 \
222     tmp2 = (vec_s16) vec_perm(tmp, (vec_u8) zero, prm);
223 #else
224 #define GET_TMP2(dest, prm)                                 \
225     tmp  = vec_vsx_ld(0, dest);                             \
226     tmp2 = (vec_s16) vec_mergeh(tmp, (vec_u8) zero)
227 #endif
228 
229 #define ADD(dest, src, perm)                                \
230     GET_TMP2(dest, perm);                                   \
231     tmp3 = vec_adds(tmp2, src);                             \
232     tmp  = vec_packsu(tmp3, tmp3);                          \
233     vec_ste((vec_u32) tmp, 0, (unsigned int *) dest);       \
234     vec_ste((vec_u32) tmp, 4, (unsigned int *) dest)
235 
236     ADD(dest, vx0, perm0);
237     dest += stride;
238     ADD(dest, vx1, perm1);
239     dest += stride;
240     ADD(dest, vx2, perm0);
241     dest += stride;
242     ADD(dest, vx3, perm1);
243     dest += stride;
244     ADD(dest, vx4, perm0);
245     dest += stride;
246     ADD(dest, vx5, perm1);
247     dest += stride;
248     ADD(dest, vx6, perm0);
249     dest += stride;
250     ADD(dest, vx7, perm1);
251 }
252 
253 #endif /* HAVE_ALTIVEC */
254 
ff_idctdsp_init_ppc(IDCTDSPContext * c,AVCodecContext * avctx,unsigned high_bit_depth)255 av_cold void ff_idctdsp_init_ppc(IDCTDSPContext *c, AVCodecContext *avctx,
256                                  unsigned high_bit_depth)
257 {
258 #if HAVE_ALTIVEC
259     if (!PPC_ALTIVEC(av_get_cpu_flags()))
260         return;
261 
262     if (!high_bit_depth && avctx->lowres == 0) {
263         if ((avctx->idct_algo == FF_IDCT_AUTO && !(avctx->flags & AV_CODEC_FLAG_BITEXACT)) ||
264             (avctx->idct_algo == FF_IDCT_ALTIVEC)) {
265             c->idct      = idct_altivec;
266             c->idct_add  = idct_add_altivec;
267             c->idct_put  = idct_put_altivec;
268             c->perm_type = FF_IDCT_PERM_TRANSPOSE;
269         }
270     }
271 #endif /* HAVE_ALTIVEC */
272 }
273