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lossless_videodsp.c
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1 /*
2  * Lossless video DSP utils
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 #include "avcodec.h"
21 #include "lossless_videodsp.h"
22 #include "libavcodec/mathops.h"
23 
24 static void add_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, int w){
25  long i;
26  unsigned long pw_lsb = (mask >> 1) * 0x0001000100010001ULL;
27  unsigned long pw_msb = pw_lsb + 0x0001000100010001ULL;
28  for (i = 0; i <= w - (int)sizeof(long)/2; i += sizeof(long)/2) {
29  long a = *(long*)(src+i);
30  long b = *(long*)(dst+i);
31  *(long*)(dst+i) = ((a&pw_lsb) + (b&pw_lsb)) ^ ((a^b)&pw_msb);
32  }
33  for(; i<w; i++)
34  dst[i] = (dst[i] + src[i]) & mask;
35 }
36 
37 static void diff_int16_c(uint16_t *dst, const uint16_t *src1, const uint16_t *src2, unsigned mask, int w){
38  long i;
39 #if !HAVE_FAST_UNALIGNED
40  if((long)src2 & (sizeof(long)-1)){
41  for(i=0; i+3<w; i+=4){
42  dst[i+0] = (src1[i+0]-src2[i+0]) & mask;
43  dst[i+1] = (src1[i+1]-src2[i+1]) & mask;
44  dst[i+2] = (src1[i+2]-src2[i+2]) & mask;
45  dst[i+3] = (src1[i+3]-src2[i+3]) & mask;
46  }
47  }else
48 #endif
49  {
50  unsigned long pw_lsb = (mask >> 1) * 0x0001000100010001ULL;
51  unsigned long pw_msb = pw_lsb + 0x0001000100010001ULL;
52 
53  for (i = 0; i <= w - (int)sizeof(long)/2; i += sizeof(long)/2) {
54  long a = *(long*)(src1+i);
55  long b = *(long*)(src2+i);
56  *(long*)(dst+i) = ((a|pw_msb) - (b&pw_lsb)) ^ ((a^b^pw_msb)&pw_msb);
57  }
58  }
59  for (; i<w; i++)
60  dst[i] = (src1[i] - src2[i]) & mask;
61 }
62 
63 static void add_hfyu_median_prediction_int16_c(uint16_t *dst, const uint16_t *src, const uint16_t *diff, unsigned mask, int w, int *left, int *left_top){
64  int i;
65  uint16_t l, lt;
66 
67  l = *left;
68  lt = *left_top;
69 
70  for(i=0; i<w; i++){
71  l = (mid_pred(l, src[i], (l + src[i] - lt) & mask) + diff[i]) & mask;
72  lt = src[i];
73  dst[i] = l;
74  }
75 
76  *left = l;
77  *left_top = lt;
78 }
79 
80 static void sub_hfyu_median_prediction_int16_c(uint16_t *dst, const uint16_t *src1, const uint16_t *src2, unsigned mask, int w, int *left, int *left_top){
81  int i;
82  uint16_t l, lt;
83 
84  l = *left;
85  lt = *left_top;
86 
87  for(i=0; i<w; i++){
88  const int pred = mid_pred(l, src1[i], (l + src1[i] - lt) & mask);
89  lt = src1[i];
90  l = src2[i];
91  dst[i] = (l - pred) & mask;
92  }
93 
94  *left = l;
95  *left_top = lt;
96 }
97 
98 static int add_hfyu_left_prediction_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, int w, unsigned acc){
99  int i;
100 
101  for(i=0; i<w-1; i++){
102  acc+= src[i];
103  dst[i]= acc & mask;
104  i++;
105  acc+= src[i];
106  dst[i]= acc & mask;
107  }
108 
109  for(; i<w; i++){
110  acc+= src[i];
111  dst[i]= acc & mask;
112  }
113 
114  return acc;
115 }
116 
117 
119 {
120  c->add_int16 = add_int16_c;
125 
126  if (ARCH_X86)
127  ff_llviddsp_init_x86(c, avctx);
128 }