FFmpeg
simple_idct.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 #include "libavutil/intreadwrite.h"
29 #include "avcodec.h"
30 #include "mathops.h"
31 #include "simple_idct.h"
32 
33 #define IN_IDCT_DEPTH 16
34 
35 #define BIT_DEPTH 8
36 #include "simple_idct_template.c"
37 #undef BIT_DEPTH
38 
39 #define BIT_DEPTH 10
40 #include "simple_idct_template.c"
41 
42 #define EXTRA_SHIFT 2
43 #include "simple_idct_template.c"
44 
45 #undef EXTRA_SHIFT
46 #undef BIT_DEPTH
47 
48 #define BIT_DEPTH 12
49 #include "simple_idct_template.c"
50 #undef BIT_DEPTH
51 #undef IN_IDCT_DEPTH
52 
53 #define IN_IDCT_DEPTH 32
54 #define BIT_DEPTH 10
55 #include "simple_idct_template.c"
56 #undef BIT_DEPTH
57 #undef IN_IDCT_DEPTH
58 
59 /* 2x4x8 idct */
60 
61 #define CN_SHIFT 12
62 #define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
63 #define C1 C_FIX(0.6532814824)
64 #define C2 C_FIX(0.2705980501)
65 
66 /* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
67  and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
68 #define C_SHIFT (4+1+12)
69 
70 static inline void idct4col_put(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
71 {
72  int c0, c1, c2, c3, a0, a1, a2, a3;
73 
74  a0 = col[8*0];
75  a1 = col[8*2];
76  a2 = col[8*4];
77  a3 = col[8*6];
78  c0 = ((a0 + a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
79  c2 = ((a0 - a2) * (1 << CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
80  c1 = a1 * C1 + a3 * C2;
81  c3 = a1 * C2 - a3 * C1;
82  dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT);
83  dest += line_size;
84  dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT);
85  dest += line_size;
86  dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT);
87  dest += line_size;
88  dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT);
89 }
90 
91 #define BF(k) \
92 {\
93  int a0, a1;\
94  a0 = ptr[k];\
95  a1 = ptr[8 + k];\
96  ptr[k] = a0 + a1;\
97  ptr[8 + k] = a0 - a1;\
98 }
99 
100 /* only used by DV codec. The input must be interlaced. 128 is added
101  to the pixels before clamping to avoid systematic error
102  (1024*sqrt(2)) offset would be needed otherwise. */
103 /* XXX: I think a 1.0/sqrt(2) normalization should be needed to
104  compensate the extra butterfly stage - I don't have the full DV
105  specification */
106 void ff_simple_idct248_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
107 {
108  int i;
109  int16_t *ptr;
110 
111  /* butterfly */
112  ptr = block;
113  for(i=0;i<4;i++) {
114  BF(0);
115  BF(1);
116  BF(2);
117  BF(3);
118  BF(4);
119  BF(5);
120  BF(6);
121  BF(7);
122  ptr += 2 * 8;
123  }
124 
125  /* IDCT8 on each line */
126  for(i=0; i<8; i++) {
127  idctRowCondDC_int16_8bit(block + i*8, 0);
128  }
129 
130  /* IDCT4 and store */
131  for(i=0;i<8;i++) {
132  idct4col_put(dest + i, 2 * line_size, block + i);
133  idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i);
134  }
135 }
136 
137 /* 8x4 & 4x8 WMV2 IDCT */
138 #undef CN_SHIFT
139 #undef C_SHIFT
140 #undef C_FIX
141 #undef C1
142 #undef C2
143 #define CN_SHIFT 12
144 #define C_FIX(x) ((int)((x) * M_SQRT2 * (1 << CN_SHIFT) + 0.5))
145 #define C1 C_FIX(0.6532814824)
146 #define C2 C_FIX(0.2705980501)
147 #define C3 C_FIX(0.5)
148 #define C_SHIFT (4+1+12)
149 static inline void idct4col_add(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
150 {
151  int c0, c1, c2, c3, a0, a1, a2, a3;
152 
153  a0 = col[8*0];
154  a1 = col[8*1];
155  a2 = col[8*2];
156  a3 = col[8*3];
157  c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1));
158  c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1));
159  c1 = a1 * C1 + a3 * C2;
160  c3 = a1 * C2 - a3 * C1;
161  dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT));
162  dest += line_size;
163  dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT));
164  dest += line_size;
165  dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT));
166  dest += line_size;
167  dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT));
168 }
169 
170 #define RN_SHIFT 15
171 #define R_FIX(x) ((int)((x) * M_SQRT2 * (1 << RN_SHIFT) + 0.5))
172 #define R1 R_FIX(0.6532814824)
173 #define R2 R_FIX(0.2705980501)
174 #define R3 R_FIX(0.5)
175 #define R_SHIFT 11
176 static inline void idct4row(int16_t *row)
177 {
178  int c0, c1, c2, c3, a0, a1, a2, a3;
179 
180  a0 = row[0];
181  a1 = row[1];
182  a2 = row[2];
183  a3 = row[3];
184  c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1));
185  c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1));
186  c1 = a1 * R1 + a3 * R2;
187  c3 = a1 * R2 - a3 * R1;
188  row[0]= (c0 + c1) >> R_SHIFT;
189  row[1]= (c2 + c3) >> R_SHIFT;
190  row[2]= (c2 - c3) >> R_SHIFT;
191  row[3]= (c0 - c1) >> R_SHIFT;
192 }
193 
194 void ff_simple_idct84_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
195 {
196  int i;
197 
198  /* IDCT8 on each line */
199  for(i=0; i<4; i++) {
200  idctRowCondDC_int16_8bit(block + i*8, 0);
201  }
202 
203  /* IDCT4 and store */
204  for(i=0;i<8;i++) {
205  idct4col_add(dest + i, line_size, block + i);
206  }
207 }
208 
209 void ff_simple_idct48_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
210 {
211  int i;
212 
213  /* IDCT4 on each line */
214  for(i=0; i<8; i++) {
215  idct4row(block + i*8);
216  }
217 
218  /* IDCT8 and store */
219  for(i=0; i<4; i++){
220  idctSparseColAdd_int16_8bit(dest + i, line_size, block + i);
221  }
222 }
223 
224 void ff_simple_idct44_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
225 {
226  int i;
227 
228  /* IDCT4 on each line */
229  for(i=0; i<4; i++) {
230  idct4row(block + i*8);
231  }
232 
233  /* IDCT4 and store */
234  for(i=0; i<4; i++){
235  idct4col_add(dest + i, line_size, block + i);
236  }
237 }
238 
239 void ff_prores_idct_10(int16_t *block, const int16_t *qmat)
240 {
241  int i;
242 
243  for (i = 0; i < 64; i++)
244  block[i] *= qmat[i];
245 
246  for (i = 0; i < 8; i++)
247  idctRowCondDC_extrashift_10(block + i*8, 2);
248 
249  for (i = 0; i < 8; i++) {
250  block[i] += 8192;
251  idctSparseCol_extrashift_10(block + i);
252  }
253 }
254 
255 void ff_prores_idct_12(int16_t *block, const int16_t *qmat)
256 {
257  int i;
258 
259  for (i = 0; i < 64; i++)
260  block[i] *= qmat[i];
261 
262  for (i = 0; i < 8; i++)
263  idctRowCondDC_int16_12bit(block + i*8, 0);
264 
265  for (i = 0; i < 8; i++) {
266  block[i] += 8192;
267  idctSparseCol_int16_12bit(block + i);
268  }
269 }
#define a0
Definition: regdef.h:46
#define R2
Definition: simple_idct.c:173
#define a1
Definition: regdef.h:47
#define C2
Definition: simple_idct.c:146
#define CN_SHIFT
Definition: simple_idct.c:143
#define a3
Definition: regdef.h:49
The exact code depends on how similar the blocks are and how related they are to the block
uint8_t
void ff_prores_idct_12(int16_t *block, const int16_t *qmat)
Definition: simple_idct.c:255
static const uint64_t c1
Definition: murmur3.c:49
#define C1
Definition: simple_idct.c:145
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define C_SHIFT
Definition: simple_idct.c:148
void ff_prores_idct_10(int16_t *block, const int16_t *qmat)
Special version of ff_simple_idct_int16_10bit() which does dequantization and scales by a factor of 2...
Definition: simple_idct.c:239
static void idct4row(int16_t *row)
Definition: simple_idct.c:176
void ff_simple_idct44_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
Definition: simple_idct.c:224
simpleidct in C.
#define a2
Definition: regdef.h:48
static void idct4col_put(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
Definition: simple_idct.c:70
#define R1
Definition: simple_idct.c:172
#define R3
Definition: simple_idct.c:174
Libavcodec external API header.
void ff_simple_idct84_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
Definition: simple_idct.c:194
#define C3
Definition: simple_idct.c:147
void ff_simple_idct248_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
Definition: simple_idct.c:106
#define BF(k)
Definition: simple_idct.c:91
static const uint64_t c2
Definition: murmur3.c:50
simple idct header.
#define R_SHIFT
Definition: simple_idct.c:175
static void idct4col_add(uint8_t *dest, ptrdiff_t line_size, const int16_t *col)
Definition: simple_idct.c:149
void ff_simple_idct48_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
Definition: simple_idct.c:209