FFmpeg  4.0
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 "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 
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 
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 
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 
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 }
FF_IDCT_ALTIVEC
#define FF_IDCT_ALTIVEC
Definition: avcodec.h:2719
blk
#define blk(i)
Definition: sha.c:185
stride
int stride
Definition: mace.c:144
attributes.h
Macro definitions for various function/variable attributes.
ff_idctdsp_init_ppc
av_cold void ff_idctdsp_init_ppc(IDCTDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: idctdsp.c:255
block
static int16_t block[64]
Definition: dct.c:115
uint8_t
uint8_t
Definition: audio_convert.c:194
av_cold
#define av_cold
Definition: attributes.h:82
AVCodecContext::lowres
int lowres
low resolution decoding, 1-> 1/2 size, 2->1/4 size
Definition: avcodec.h:2749
FF_IDCT_AUTO
#define FF_IDCT_AUTO
Definition: avcodec.h:2714
vec_s16
#define vec_s16
Definition: util_altivec.h:37
ADD
#define ADD(a, b)
Definition: dct32_template.c:123
PPC_ALTIVEC
#define PPC_ALTIVEC(flags)
Definition: cpu.h:25
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1598
constants
static const struct @244 constants[]
AV_CODEC_FLAG_BITEXACT
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:886
AVCodecContext::idct_algo
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
Definition: avcodec.h:2713
IDCT
#define IDCT(H)
Definition: hevcdsp_template.c:240
IDCTDSPContext::idct_add
void(* idct_add)(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
block -> idct -> add dest -> clip to unsigned 8 bit -> dest.
Definition: idctdsp.h:79
vec_u8
#define vec_u8
Definition: util_altivec.h:34
IDCTDSPContext::idct_put
void(* idct_put)(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
block -> idct -> clip to unsigned 8 bit -> dest.
Definition: idctdsp.h:72
AVCodecContext
main external API structure.
Definition: avcodec.h:1518
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:93
util_altivec.h
Contains misc utility macros and inline functions.
COPY
#define COPY(src, name)
c
static double c[64]
Definition: vsrc_mptestsrc.c:87
IDCTDSPContext::idct
void(* idct)(int16_t *block)
Definition: idctdsp.h:65
IDCTDSPContext::perm_type
enum idct_permutation_type perm_type
Definition: idctdsp.h:97
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:26
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