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