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simple_idct_template.c
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1 /*
2  * Simple IDCT
3  *
4  * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
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 /**
24  * @file
25  * simpleidct in C.
26  */
27 
28 /*
29  based upon some outcommented c code from mpeg2dec (idct_mmx.c
30  written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)
31  */
32 
33 #include "simple_idct.h"
34 
35 #include "bit_depth_template.c"
36 
37 #undef W1
38 #undef W2
39 #undef W3
40 #undef W4
41 #undef W5
42 #undef W6
43 #undef W7
44 #undef ROW_SHIFT
45 #undef COL_SHIFT
46 #undef DC_SHIFT
47 #undef MUL
48 #undef MAC
49 
50 #if BIT_DEPTH == 8
51 
52 #define W1 22725 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
53 #define W2 21407 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
54 #define W3 19266 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
55 #define W4 16383 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
56 #define W5 12873 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
57 #define W6 8867 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
58 #define W7 4520 //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
59 
60 #define ROW_SHIFT 11
61 #define COL_SHIFT 20
62 #define DC_SHIFT 3
63 
64 #define MUL(a, b) MUL16(a, b)
65 #define MAC(a, b, c) MAC16(a, b, c)
66 
67 #elif BIT_DEPTH == 10 || BIT_DEPTH == 12
68 
69 #if BIT_DEPTH == 10
70 #define W1 (22725*4) // 90901
71 #define W2 (21407*4) // 85627
72 #define W3 (19265*4) // 77062
73 #define W4 (16384*4) // 65535
74 #define W5 (12873*4) // 51491
75 #define W6 ( 8867*4) // 35468
76 #define W7 ( 4520*4) // 18081
77 
78 #define ROW_SHIFT 15
79 #define COL_SHIFT 20
80 #define DC_SHIFT 1
81 #else
82 #define W1 45451
83 #define W2 42813
84 #define W3 38531
85 #define W4 32767
86 #define W5 25746
87 #define W6 17734
88 #define W7 9041
89 
90 #define ROW_SHIFT 16
91 #define COL_SHIFT 17
92 #define DC_SHIFT -1
93 #endif
94 
95 #define MUL(a, b) ((a) * (b))
96 #define MAC(a, b, c) ((a) += (b) * (c))
97 
98 #else
99 
100 #error "Unsupported bitdepth"
101 
102 #endif
103 
104 static inline void FUNC(idctRowCondDC)(int16_t *row, int extra_shift)
105 {
106  int a0, a1, a2, a3, b0, b1, b2, b3;
107 
108 #if HAVE_FAST_64BIT
109 #define ROW0_MASK (0xffffLL << 48 * HAVE_BIGENDIAN)
110  if (((((uint64_t *)row)[0] & ~ROW0_MASK) | ((uint64_t *)row)[1]) == 0) {
111  uint64_t temp;
112  if (DC_SHIFT - extra_shift >= 0) {
113  temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
114  } else {
115  temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
116  }
117  temp += temp * (1 << 16);
118  temp += temp * ((uint64_t) 1 << 32);
119  ((uint64_t *)row)[0] = temp;
120  ((uint64_t *)row)[1] = temp;
121  return;
122  }
123 #else
124  if (!(((uint32_t*)row)[1] |
125  ((uint32_t*)row)[2] |
126  ((uint32_t*)row)[3] |
127  row[1])) {
128  uint32_t temp;
129  if (DC_SHIFT - extra_shift >= 0) {
130  temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
131  } else {
132  temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
133  }
134  temp += temp * (1 << 16);
135  ((uint32_t*)row)[0]=((uint32_t*)row)[1] =
136  ((uint32_t*)row)[2]=((uint32_t*)row)[3] = temp;
137  return;
138  }
139 #endif
140 
141  a0 = (W4 * row[0]) + (1 << (ROW_SHIFT + extra_shift - 1));
142  a1 = a0;
143  a2 = a0;
144  a3 = a0;
145 
146  a0 += W2 * row[2];
147  a1 += W6 * row[2];
148  a2 -= W6 * row[2];
149  a3 -= W2 * row[2];
150 
151  b0 = MUL(W1, row[1]);
152  MAC(b0, W3, row[3]);
153  b1 = MUL(W3, row[1]);
154  MAC(b1, -W7, row[3]);
155  b2 = MUL(W5, row[1]);
156  MAC(b2, -W1, row[3]);
157  b3 = MUL(W7, row[1]);
158  MAC(b3, -W5, row[3]);
159 
160  if (AV_RN64A(row + 4)) {
161  a0 += W4*row[4] + W6*row[6];
162  a1 += - W4*row[4] - W2*row[6];
163  a2 += - W4*row[4] + W2*row[6];
164  a3 += W4*row[4] - W6*row[6];
165 
166  MAC(b0, W5, row[5]);
167  MAC(b0, W7, row[7]);
168 
169  MAC(b1, -W1, row[5]);
170  MAC(b1, -W5, row[7]);
171 
172  MAC(b2, W7, row[5]);
173  MAC(b2, W3, row[7]);
174 
175  MAC(b3, W3, row[5]);
176  MAC(b3, -W1, row[7]);
177  }
178 
179  row[0] = (a0 + b0) >> (ROW_SHIFT + extra_shift);
180  row[7] = (a0 - b0) >> (ROW_SHIFT + extra_shift);
181  row[1] = (a1 + b1) >> (ROW_SHIFT + extra_shift);
182  row[6] = (a1 - b1) >> (ROW_SHIFT + extra_shift);
183  row[2] = (a2 + b2) >> (ROW_SHIFT + extra_shift);
184  row[5] = (a2 - b2) >> (ROW_SHIFT + extra_shift);
185  row[3] = (a3 + b3) >> (ROW_SHIFT + extra_shift);
186  row[4] = (a3 - b3) >> (ROW_SHIFT + extra_shift);
187 }
188 
189 #define IDCT_COLS do { \
190  a0 = W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4)); \
191  a1 = a0; \
192  a2 = a0; \
193  a3 = a0; \
194  \
195  a0 += W2*col[8*2]; \
196  a1 += W6*col[8*2]; \
197  a2 += -W6*col[8*2]; \
198  a3 += -W2*col[8*2]; \
199  \
200  b0 = MUL(W1, col[8*1]); \
201  b1 = MUL(W3, col[8*1]); \
202  b2 = MUL(W5, col[8*1]); \
203  b3 = MUL(W7, col[8*1]); \
204  \
205  MAC(b0, W3, col[8*3]); \
206  MAC(b1, -W7, col[8*3]); \
207  MAC(b2, -W1, col[8*3]); \
208  MAC(b3, -W5, col[8*3]); \
209  \
210  if (col[8*4]) { \
211  a0 += W4*col[8*4]; \
212  a1 += -W4*col[8*4]; \
213  a2 += -W4*col[8*4]; \
214  a3 += W4*col[8*4]; \
215  } \
216  \
217  if (col[8*5]) { \
218  MAC(b0, W5, col[8*5]); \
219  MAC(b1, -W1, col[8*5]); \
220  MAC(b2, W7, col[8*5]); \
221  MAC(b3, W3, col[8*5]); \
222  } \
223  \
224  if (col[8*6]) { \
225  a0 += W6*col[8*6]; \
226  a1 += -W2*col[8*6]; \
227  a2 += W2*col[8*6]; \
228  a3 += -W6*col[8*6]; \
229  } \
230  \
231  if (col[8*7]) { \
232  MAC(b0, W7, col[8*7]); \
233  MAC(b1, -W5, col[8*7]); \
234  MAC(b2, W3, col[8*7]); \
235  MAC(b3, -W1, col[8*7]); \
236  } \
237  } while (0)
238 
239 static inline void FUNC(idctSparseColPut)(pixel *dest, int line_size,
240  int16_t *col)
241 {
242  int a0, a1, a2, a3, b0, b1, b2, b3;
243 
244  IDCT_COLS;
245 
246  dest[0] = av_clip_pixel((a0 + b0) >> COL_SHIFT);
247  dest += line_size;
248  dest[0] = av_clip_pixel((a1 + b1) >> COL_SHIFT);
249  dest += line_size;
250  dest[0] = av_clip_pixel((a2 + b2) >> COL_SHIFT);
251  dest += line_size;
252  dest[0] = av_clip_pixel((a3 + b3) >> COL_SHIFT);
253  dest += line_size;
254  dest[0] = av_clip_pixel((a3 - b3) >> COL_SHIFT);
255  dest += line_size;
256  dest[0] = av_clip_pixel((a2 - b2) >> COL_SHIFT);
257  dest += line_size;
258  dest[0] = av_clip_pixel((a1 - b1) >> COL_SHIFT);
259  dest += line_size;
260  dest[0] = av_clip_pixel((a0 - b0) >> COL_SHIFT);
261 }
262 
263 static inline void FUNC(idctSparseColAdd)(pixel *dest, int line_size,
264  int16_t *col)
265 {
266  int a0, a1, a2, a3, b0, b1, b2, b3;
267 
268  IDCT_COLS;
269 
270  dest[0] = av_clip_pixel(dest[0] + ((a0 + b0) >> COL_SHIFT));
271  dest += line_size;
272  dest[0] = av_clip_pixel(dest[0] + ((a1 + b1) >> COL_SHIFT));
273  dest += line_size;
274  dest[0] = av_clip_pixel(dest[0] + ((a2 + b2) >> COL_SHIFT));
275  dest += line_size;
276  dest[0] = av_clip_pixel(dest[0] + ((a3 + b3) >> COL_SHIFT));
277  dest += line_size;
278  dest[0] = av_clip_pixel(dest[0] + ((a3 - b3) >> COL_SHIFT));
279  dest += line_size;
280  dest[0] = av_clip_pixel(dest[0] + ((a2 - b2) >> COL_SHIFT));
281  dest += line_size;
282  dest[0] = av_clip_pixel(dest[0] + ((a1 - b1) >> COL_SHIFT));
283  dest += line_size;
284  dest[0] = av_clip_pixel(dest[0] + ((a0 - b0) >> COL_SHIFT));
285 }
286 
287 static inline void FUNC(idctSparseCol)(int16_t *col)
288 {
289  int a0, a1, a2, a3, b0, b1, b2, b3;
290 
291  IDCT_COLS;
292 
293  col[0 ] = ((a0 + b0) >> COL_SHIFT);
294  col[8 ] = ((a1 + b1) >> COL_SHIFT);
295  col[16] = ((a2 + b2) >> COL_SHIFT);
296  col[24] = ((a3 + b3) >> COL_SHIFT);
297  col[32] = ((a3 - b3) >> COL_SHIFT);
298  col[40] = ((a2 - b2) >> COL_SHIFT);
299  col[48] = ((a1 - b1) >> COL_SHIFT);
300  col[56] = ((a0 - b0) >> COL_SHIFT);
301 }
302 
303 void FUNC(ff_simple_idct_put)(uint8_t *dest_, int line_size, int16_t *block)
304 {
305  pixel *dest = (pixel *)dest_;
306  int i;
307 
308  line_size /= sizeof(pixel);
309 
310  for (i = 0; i < 8; i++)
311  FUNC(idctRowCondDC)(block + i*8, 0);
312 
313  for (i = 0; i < 8; i++)
314  FUNC(idctSparseColPut)(dest + i, line_size, block + i);
315 }
316 
317 void FUNC(ff_simple_idct_add)(uint8_t *dest_, int line_size, int16_t *block)
318 {
319  pixel *dest = (pixel *)dest_;
320  int i;
321 
322  line_size /= sizeof(pixel);
323 
324  for (i = 0; i < 8; i++)
325  FUNC(idctRowCondDC)(block + i*8, 0);
326 
327  for (i = 0; i < 8; i++)
328  FUNC(idctSparseColAdd)(dest + i, line_size, block + i);
329 }
330 
331 void FUNC(ff_simple_idct)(int16_t *block)
332 {
333  int i;
334 
335  for (i = 0; i < 8; i++)
336  FUNC(idctRowCondDC)(block + i*8, 0);
337 
338  for (i = 0; i < 8; i++)
339  FUNC(idctSparseCol)(block + i);
340 }
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