• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 /* Based upon some commented-out C code from mpeg2dec (idct_mmx.c
29  * written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>). */
30 
31 #include "simple_idct.h"
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 22725 // 90901
69 #define W2 21407 //  85627
70 #define W3 19265 //  77062
71 #define W4 16384 //  65535
72 #define W5 12873 //  51491
73 #define W6  8867 //  35468
74 #define W7  4520 //  18081
75 
76 #   ifdef EXTRA_SHIFT
77 #define ROW_SHIFT 13
78 #define COL_SHIFT 18
79 #define DC_SHIFT  1
80 #   elif IN_IDCT_DEPTH == 32
81 #define ROW_SHIFT 13
82 #define COL_SHIFT 21
83 #define DC_SHIFT  2
84 #   else
85 #define ROW_SHIFT 12
86 #define COL_SHIFT 19
87 #define DC_SHIFT  2
88 #   endif
89 
90 # else
91 #define W1 45451
92 #define W2 42813
93 #define W3 38531
94 #define W4 32767
95 #define W5 25746
96 #define W6 17734
97 #define W7 9041
98 
99 #define ROW_SHIFT 16
100 #define COL_SHIFT 17
101 #define DC_SHIFT -1
102 # endif
103 
104 #define MUL(a, b)    ((int)((SUINT)(a) * (b)))
105 #define MAC(a, b, c) ((a) += (SUINT)(b) * (c))
106 
107 #else
108 
109 #error "Unsupported bitdepth"
110 
111 #endif
112 
113 #ifdef EXTRA_SHIFT
FUNC(idctRowCondDC_extrashift)114 static inline void FUNC(idctRowCondDC_extrashift)(int16_t *row, int extra_shift)
115 #else
116 static inline void FUNC6(idctRowCondDC)(idctin *row, int extra_shift)
117 #endif
118 {
119     SUINT a0, a1, a2, a3, b0, b1, b2, b3;
120 
121 // TODO: Add DC-only support for int32_t input
122 #if IN_IDCT_DEPTH == 16
123 #if HAVE_FAST_64BIT
124 #define ROW0_MASK (0xffffULL << 48 * HAVE_BIGENDIAN)
125     if (((AV_RN64A(row) & ~ROW0_MASK) | AV_RN64A(row+4)) == 0) {
126         uint64_t temp;
127         if (DC_SHIFT - extra_shift >= 0) {
128             temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
129         } else {
130             temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
131         }
132         temp += temp * (1 << 16);
133         temp += temp * ((uint64_t) 1 << 32);
134         AV_WN64A(row, temp);
135         AV_WN64A(row + 4, temp);
136         return;
137     }
138 #else
139     if (!(AV_RN32A(row+2) |
140           AV_RN32A(row+4) |
141           AV_RN32A(row+6) |
142           row[1])) {
143         uint32_t temp;
144         if (DC_SHIFT - extra_shift >= 0) {
145             temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
146         } else {
147             temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
148         }
149         temp += temp * (1 << 16);
150         AV_WN32A(row, temp);
151         AV_WN32A(row+2, temp);
152         AV_WN32A(row+4, temp);
153         AV_WN32A(row+6, temp);
154         return;
155     }
156 #endif
157 #endif
158 
159     a0 = ((SUINT)W4 * row[0]) + (1 << (ROW_SHIFT + extra_shift - 1));
160     a1 = a0;
161     a2 = a0;
162     a3 = a0;
163 
164     a0 += (SUINT)W2 * row[2];
165     a1 += (SUINT)W6 * row[2];
166     a2 -= (SUINT)W6 * row[2];
167     a3 -= (SUINT)W2 * row[2];
168 
169     b0 = MUL(W1, row[1]);
170     MAC(b0, W3, row[3]);
171     b1 = MUL(W3, row[1]);
172     MAC(b1, -W7, row[3]);
173     b2 = MUL(W5, row[1]);
174     MAC(b2, -W1, row[3]);
175     b3 = MUL(W7, row[1]);
176     MAC(b3, -W5, row[3]);
177 
178 #if IN_IDCT_DEPTH == 32
179     if (AV_RN64A(row + 4) | AV_RN64A(row + 6)) {
180 #else
181     if (AV_RN64A(row + 4)) {
182 #endif
183         a0 += (SUINT)  W4*row[4] + (SUINT)W6*row[6];
184         a1 += (SUINT)- W4*row[4] - (SUINT)W2*row[6];
185         a2 += (SUINT)- W4*row[4] + (SUINT)W2*row[6];
186         a3 += (SUINT)  W4*row[4] - (SUINT)W6*row[6];
187 
188         MAC(b0,  W5, row[5]);
189         MAC(b0,  W7, row[7]);
190 
191         MAC(b1, -W1, row[5]);
192         MAC(b1, -W5, row[7]);
193 
194         MAC(b2,  W7, row[5]);
195         MAC(b2,  W3, row[7]);
196 
197         MAC(b3,  W3, row[5]);
198         MAC(b3, -W1, row[7]);
199     }
200 
201     row[0] = (int)(a0 + b0) >> (ROW_SHIFT + extra_shift);
202     row[7] = (int)(a0 - b0) >> (ROW_SHIFT + extra_shift);
203     row[1] = (int)(a1 + b1) >> (ROW_SHIFT + extra_shift);
204     row[6] = (int)(a1 - b1) >> (ROW_SHIFT + extra_shift);
205     row[2] = (int)(a2 + b2) >> (ROW_SHIFT + extra_shift);
206     row[5] = (int)(a2 - b2) >> (ROW_SHIFT + extra_shift);
207     row[3] = (int)(a3 + b3) >> (ROW_SHIFT + extra_shift);
208     row[4] = (int)(a3 - b3) >> (ROW_SHIFT + extra_shift);
209 }
210 
211 #define IDCT_COLS do {                                  \
212         a0 = (SUINT)W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4)); \
213         a1 = a0;                                        \
214         a2 = a0;                                        \
215         a3 = a0;                                        \
216                                                         \
217         a0 += (SUINT) W2*col[8*2];                             \
218         a1 += (SUINT) W6*col[8*2];                             \
219         a2 += (SUINT)-W6*col[8*2];                             \
220         a3 += (SUINT)-W2*col[8*2];                             \
221                                                         \
222         b0 = MUL(W1, col[8*1]);                         \
223         b1 = MUL(W3, col[8*1]);                         \
224         b2 = MUL(W5, col[8*1]);                         \
225         b3 = MUL(W7, col[8*1]);                         \
226                                                         \
227         MAC(b0,  W3, col[8*3]);                         \
228         MAC(b1, -W7, col[8*3]);                         \
229         MAC(b2, -W1, col[8*3]);                         \
230         MAC(b3, -W5, col[8*3]);                         \
231                                                         \
232         if (col[8*4]) {                                 \
233             a0 += (SUINT) W4*col[8*4];                         \
234             a1 += (SUINT)-W4*col[8*4];                         \
235             a2 += (SUINT)-W4*col[8*4];                         \
236             a3 += (SUINT) W4*col[8*4];                         \
237         }                                               \
238                                                         \
239         if (col[8*5]) {                                 \
240             MAC(b0,  W5, col[8*5]);                     \
241             MAC(b1, -W1, col[8*5]);                     \
242             MAC(b2,  W7, col[8*5]);                     \
243             MAC(b3,  W3, col[8*5]);                     \
244         }                                               \
245                                                         \
246         if (col[8*6]) {                                 \
247             a0 += (SUINT) W6*col[8*6];                         \
248             a1 += (SUINT)-W2*col[8*6];                         \
249             a2 += (SUINT) W2*col[8*6];                         \
250             a3 += (SUINT)-W6*col[8*6];                         \
251         }                                               \
252                                                         \
253         if (col[8*7]) {                                 \
254             MAC(b0,  W7, col[8*7]);                     \
255             MAC(b1, -W5, col[8*7]);                     \
256             MAC(b2,  W3, col[8*7]);                     \
257             MAC(b3, -W1, col[8*7]);                     \
258         }                                               \
259     } while (0)
260 
261 #ifdef EXTRA_SHIFT
262 static inline void FUNC(idctSparseCol_extrashift)(int16_t *col)
263 #else
264 static inline void FUNC6(idctSparseColPut)(pixel *dest, ptrdiff_t line_size,
265                                           idctin *col)
266 {
267     SUINT a0, a1, a2, a3, b0, b1, b2, b3;
268 
269     IDCT_COLS;
270 
271     dest[0] = av_clip_pixel((int)(a0 + b0) >> COL_SHIFT);
272     dest += line_size;
273     dest[0] = av_clip_pixel((int)(a1 + b1) >> COL_SHIFT);
274     dest += line_size;
275     dest[0] = av_clip_pixel((int)(a2 + b2) >> COL_SHIFT);
276     dest += line_size;
277     dest[0] = av_clip_pixel((int)(a3 + b3) >> COL_SHIFT);
278     dest += line_size;
279     dest[0] = av_clip_pixel((int)(a3 - b3) >> COL_SHIFT);
280     dest += line_size;
281     dest[0] = av_clip_pixel((int)(a2 - b2) >> COL_SHIFT);
282     dest += line_size;
283     dest[0] = av_clip_pixel((int)(a1 - b1) >> COL_SHIFT);
284     dest += line_size;
285     dest[0] = av_clip_pixel((int)(a0 - b0) >> COL_SHIFT);
286 }
287 
288 static inline void FUNC6(idctSparseColAdd)(pixel *dest, ptrdiff_t line_size,
289                                           idctin *col)
290 {
291     unsigned a0, a1, a2, a3, b0, b1, b2, b3;
292 
293     IDCT_COLS;
294 
295     dest[0] = av_clip_pixel(dest[0] + ((int)(a0 + b0) >> COL_SHIFT));
296     dest += line_size;
297     dest[0] = av_clip_pixel(dest[0] + ((int)(a1 + b1) >> COL_SHIFT));
298     dest += line_size;
299     dest[0] = av_clip_pixel(dest[0] + ((int)(a2 + b2) >> COL_SHIFT));
300     dest += line_size;
301     dest[0] = av_clip_pixel(dest[0] + ((int)(a3 + b3) >> COL_SHIFT));
302     dest += line_size;
303     dest[0] = av_clip_pixel(dest[0] + ((int)(a3 - b3) >> COL_SHIFT));
304     dest += line_size;
305     dest[0] = av_clip_pixel(dest[0] + ((int)(a2 - b2) >> COL_SHIFT));
306     dest += line_size;
307     dest[0] = av_clip_pixel(dest[0] + ((int)(a1 - b1) >> COL_SHIFT));
308     dest += line_size;
309     dest[0] = av_clip_pixel(dest[0] + ((int)(a0 - b0) >> COL_SHIFT));
310 }
311 
312 static inline void FUNC6(idctSparseCol)(idctin *col)
313 #endif
314 {
315     unsigned a0, a1, a2, a3, b0, b1, b2, b3;
316 
317     IDCT_COLS;
318 
319     col[0 ] = ((int)(a0 + b0) >> COL_SHIFT);
320     col[8 ] = ((int)(a1 + b1) >> COL_SHIFT);
321     col[16] = ((int)(a2 + b2) >> COL_SHIFT);
322     col[24] = ((int)(a3 + b3) >> COL_SHIFT);
323     col[32] = ((int)(a3 - b3) >> COL_SHIFT);
324     col[40] = ((int)(a2 - b2) >> COL_SHIFT);
325     col[48] = ((int)(a1 - b1) >> COL_SHIFT);
326     col[56] = ((int)(a0 - b0) >> COL_SHIFT);
327 }
328 
329 #ifndef EXTRA_SHIFT
330 void FUNC6(ff_simple_idct_put)(uint8_t *dest_, ptrdiff_t line_size, int16_t *block_)
331 {
332     idctin *block = (idctin *)block_;
333     pixel *dest = (pixel *)dest_;
334     int i;
335 
336     line_size /= sizeof(pixel);
337 
338     for (i = 0; i < 8; i++)
339         FUNC6(idctRowCondDC)(block + i*8, 0);
340 
341     for (i = 0; i < 8; i++)
342         FUNC6(idctSparseColPut)(dest + i, line_size, block + i);
343 }
344 
345 #if IN_IDCT_DEPTH == 16
346 void FUNC6(ff_simple_idct_add)(uint8_t *dest_, ptrdiff_t line_size, int16_t *block)
347 {
348     pixel *dest = (pixel *)dest_;
349     int i;
350 
351     line_size /= sizeof(pixel);
352 
353     for (i = 0; i < 8; i++)
354         FUNC6(idctRowCondDC)(block + i*8, 0);
355 
356     for (i = 0; i < 8; i++)
357         FUNC6(idctSparseColAdd)(dest + i, line_size, block + i);
358 }
359 
360 void FUNC6(ff_simple_idct)(int16_t *block)
361 {
362     int i;
363 
364     for (i = 0; i < 8; i++)
365         FUNC6(idctRowCondDC)(block + i*8, 0);
366 
367     for (i = 0; i < 8; i++)
368         FUNC6(idctSparseCol)(block + i);
369 }
370 #endif
371 #endif
372