04be0cef061287edfb5a33d2e515783331e7b1ff
[deb_ffmpeg.git] / simple_idct_alpha.c
1 /*
2 * Simple IDCT (Alpha optimized)
3 *
4 * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * based upon some outcommented C code from mpeg2dec (idct_mmx.c
7 * written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)
8 *
9 * Alpha optimizations by Måns Rullgård <mans@mansr.com>
10 * and Falk Hueffner <falk@debian.org>
11 *
12 * This file is part of FFmpeg.
13 *
14 * FFmpeg is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU Lesser General Public
16 * License as published by the Free Software Foundation; either
17 * version 2.1 of the License, or (at your option) any later version.
18 *
19 * FFmpeg is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * Lesser General Public License for more details.
23 *
24 * You should have received a copy of the GNU Lesser General Public
25 * License along with FFmpeg; if not, write to the Free Software
26 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 */
28
29 #include "idctdsp_alpha.h"
30 #include "asm.h"
31
32 // cos(i * M_PI / 16) * sqrt(2) * (1 << 14)
33 // W4 is actually exactly 16384, but using 16383 works around
34 // accumulating rounding errors for some encoders
35 #define W1 22725
36 #define W2 21407
37 #define W3 19266
38 #define W4 16383
39 #define W5 12873
40 #define W6 8867
41 #define W7 4520
42 #define ROW_SHIFT 11
43 #define COL_SHIFT 20
44
45 /* 0: all entries 0, 1: only first entry nonzero, 2: otherwise */
46 static inline int idct_row(int16_t *row)
47 {
48 int a0, a1, a2, a3, b0, b1, b2, b3, t;
49 uint64_t l, r, t2;
50 l = ldq(row);
51 r = ldq(row + 4);
52
53 if (l == 0 && r == 0)
54 return 0;
55
56 a0 = W4 * sextw(l) + (1 << (ROW_SHIFT - 1));
57
58 if (((l & ~0xffffUL) | r) == 0) {
59 a0 >>= ROW_SHIFT;
60 t2 = (uint16_t) a0;
61 t2 |= t2 << 16;
62 t2 |= t2 << 32;
63
64 stq(t2, row);
65 stq(t2, row + 4);
66 return 1;
67 }
68
69 a1 = a0;
70 a2 = a0;
71 a3 = a0;
72
73 t = extwl(l, 4); /* row[2] */
74 if (t != 0) {
75 t = sextw(t);
76 a0 += W2 * t;
77 a1 += W6 * t;
78 a2 -= W6 * t;
79 a3 -= W2 * t;
80 }
81
82 t = extwl(r, 0); /* row[4] */
83 if (t != 0) {
84 t = sextw(t);
85 a0 += W4 * t;
86 a1 -= W4 * t;
87 a2 -= W4 * t;
88 a3 += W4 * t;
89 }
90
91 t = extwl(r, 4); /* row[6] */
92 if (t != 0) {
93 t = sextw(t);
94 a0 += W6 * t;
95 a1 -= W2 * t;
96 a2 += W2 * t;
97 a3 -= W6 * t;
98 }
99
100 t = extwl(l, 2); /* row[1] */
101 if (t != 0) {
102 t = sextw(t);
103 b0 = W1 * t;
104 b1 = W3 * t;
105 b2 = W5 * t;
106 b3 = W7 * t;
107 } else {
108 b0 = 0;
109 b1 = 0;
110 b2 = 0;
111 b3 = 0;
112 }
113
114 t = extwl(l, 6); /* row[3] */
115 if (t) {
116 t = sextw(t);
117 b0 += W3 * t;
118 b1 -= W7 * t;
119 b2 -= W1 * t;
120 b3 -= W5 * t;
121 }
122
123
124 t = extwl(r, 2); /* row[5] */
125 if (t) {
126 t = sextw(t);
127 b0 += W5 * t;
128 b1 -= W1 * t;
129 b2 += W7 * t;
130 b3 += W3 * t;
131 }
132
133 t = extwl(r, 6); /* row[7] */
134 if (t) {
135 t = sextw(t);
136 b0 += W7 * t;
137 b1 -= W5 * t;
138 b2 += W3 * t;
139 b3 -= W1 * t;
140 }
141
142 row[0] = (a0 + b0) >> ROW_SHIFT;
143 row[1] = (a1 + b1) >> ROW_SHIFT;
144 row[2] = (a2 + b2) >> ROW_SHIFT;
145 row[3] = (a3 + b3) >> ROW_SHIFT;
146 row[4] = (a3 - b3) >> ROW_SHIFT;
147 row[5] = (a2 - b2) >> ROW_SHIFT;
148 row[6] = (a1 - b1) >> ROW_SHIFT;
149 row[7] = (a0 - b0) >> ROW_SHIFT;
150
151 return 2;
152 }
153
154 static inline void idct_col(int16_t *col)
155 {
156 int a0, a1, a2, a3, b0, b1, b2, b3;
157
158 col[0] += (1 << (COL_SHIFT - 1)) / W4;
159
160 a0 = W4 * col[8 * 0];
161 a1 = W4 * col[8 * 0];
162 a2 = W4 * col[8 * 0];
163 a3 = W4 * col[8 * 0];
164
165 if (col[8 * 2]) {
166 a0 += W2 * col[8 * 2];
167 a1 += W6 * col[8 * 2];
168 a2 -= W6 * col[8 * 2];
169 a3 -= W2 * col[8 * 2];
170 }
171
172 if (col[8 * 4]) {
173 a0 += W4 * col[8 * 4];
174 a1 -= W4 * col[8 * 4];
175 a2 -= W4 * col[8 * 4];
176 a3 += W4 * col[8 * 4];
177 }
178
179 if (col[8 * 6]) {
180 a0 += W6 * col[8 * 6];
181 a1 -= W2 * col[8 * 6];
182 a2 += W2 * col[8 * 6];
183 a3 -= W6 * col[8 * 6];
184 }
185
186 if (col[8 * 1]) {
187 b0 = W1 * col[8 * 1];
188 b1 = W3 * col[8 * 1];
189 b2 = W5 * col[8 * 1];
190 b3 = W7 * col[8 * 1];
191 } else {
192 b0 = 0;
193 b1 = 0;
194 b2 = 0;
195 b3 = 0;
196 }
197
198 if (col[8 * 3]) {
199 b0 += W3 * col[8 * 3];
200 b1 -= W7 * col[8 * 3];
201 b2 -= W1 * col[8 * 3];
202 b3 -= W5 * col[8 * 3];
203 }
204
205 if (col[8 * 5]) {
206 b0 += W5 * col[8 * 5];
207 b1 -= W1 * col[8 * 5];
208 b2 += W7 * col[8 * 5];
209 b3 += W3 * col[8 * 5];
210 }
211
212 if (col[8 * 7]) {
213 b0 += W7 * col[8 * 7];
214 b1 -= W5 * col[8 * 7];
215 b2 += W3 * col[8 * 7];
216 b3 -= W1 * col[8 * 7];
217 }
218
219 col[8 * 0] = (a0 + b0) >> COL_SHIFT;
220 col[8 * 7] = (a0 - b0) >> COL_SHIFT;
221 col[8 * 1] = (a1 + b1) >> COL_SHIFT;
222 col[8 * 6] = (a1 - b1) >> COL_SHIFT;
223 col[8 * 2] = (a2 + b2) >> COL_SHIFT;
224 col[8 * 5] = (a2 - b2) >> COL_SHIFT;
225 col[8 * 3] = (a3 + b3) >> COL_SHIFT;
226 col[8 * 4] = (a3 - b3) >> COL_SHIFT;
227 }
228
229 /* If all rows but the first one are zero after row transformation,
230 all rows will be identical after column transformation. */
231 static inline void idct_col2(int16_t *col)
232 {
233 int i;
234 uint64_t l, r;
235
236 for (i = 0; i < 8; ++i) {
237 int a0 = col[i] + (1 << (COL_SHIFT - 1)) / W4;
238
239 a0 *= W4;
240 col[i] = a0 >> COL_SHIFT;
241 }
242
243 l = ldq(col + 0 * 4); r = ldq(col + 1 * 4);
244 stq(l, col + 2 * 4); stq(r, col + 3 * 4);
245 stq(l, col + 4 * 4); stq(r, col + 5 * 4);
246 stq(l, col + 6 * 4); stq(r, col + 7 * 4);
247 stq(l, col + 8 * 4); stq(r, col + 9 * 4);
248 stq(l, col + 10 * 4); stq(r, col + 11 * 4);
249 stq(l, col + 12 * 4); stq(r, col + 13 * 4);
250 stq(l, col + 14 * 4); stq(r, col + 15 * 4);
251 }
252
253 void ff_simple_idct_axp(int16_t *block)
254 {
255
256 int i;
257 int rowsZero = 1; /* all rows except row 0 zero */
258 int rowsConstant = 1; /* all rows consist of a constant value */
259
260 for (i = 0; i < 8; i++) {
261 int sparseness = idct_row(block + 8 * i);
262
263 if (i > 0 && sparseness > 0)
264 rowsZero = 0;
265 if (sparseness == 2)
266 rowsConstant = 0;
267 }
268
269 if (rowsZero) {
270 idct_col2(block);
271 } else if (rowsConstant) {
272 idct_col(block);
273 for (i = 0; i < 8; i += 2) {
274 uint64_t v = (uint16_t) block[0];
275 uint64_t w = (uint16_t) block[8];
276
277 v |= v << 16;
278 w |= w << 16;
279 v |= v << 32;
280 w |= w << 32;
281 stq(v, block + 0 * 4);
282 stq(v, block + 1 * 4);
283 stq(w, block + 2 * 4);
284 stq(w, block + 3 * 4);
285 block += 4 * 4;
286 }
287 } else {
288 for (i = 0; i < 8; i++)
289 idct_col(block + i);
290 }
291 }
292
293 void ff_simple_idct_put_axp(uint8_t *dest, int line_size, int16_t *block)
294 {
295 ff_simple_idct_axp(block);
296 put_pixels_clamped_axp_p(block, dest, line_size);
297 }
298
299 void ff_simple_idct_add_axp(uint8_t *dest, int line_size, int16_t *block)
300 {
301 ff_simple_idct_axp(block);
302 add_pixels_clamped_axp_p(block, dest, line_size);
303 }