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
104static 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
239static 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
263static 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
287static 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
303void 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
317void 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
331void 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}
341