aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/hqxdsp.c
blob: 2a02299a29ba4be7bfc0ec00cfeb821b5e4f73b5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/*
 * HQX DSP routines
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdint.h>

#include "libavutil/common.h"

#include "hqxdsp.h"

static inline void idct_col(int16_t *blk, const uint8_t *quant)
{
    int t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, tA, tB, tC, tD, tE, tF;
    int t10, t11, t12, t13;
    int s0, s1, s2, s3, s4, s5, s6, s7;

    s0 = (int) blk[0 * 8] * quant[0 * 8];
    s1 = (int) blk[1 * 8] * quant[1 * 8];
    s2 = (int) blk[2 * 8] * quant[2 * 8];
    s3 = (int) blk[3 * 8] * quant[3 * 8];
    s4 = (int) blk[4 * 8] * quant[4 * 8];
    s5 = (int) blk[5 * 8] * quant[5 * 8];
    s6 = (int) blk[6 * 8] * quant[6 * 8];
    s7 = (int) blk[7 * 8] * quant[7 * 8];

    t0  =  (s3 * 19266 + s5 * 12873) >> 15;
    t1  =  (s5 * 19266 - s3 * 12873) >> 15;
    t2  = ((s7 * 4520  + s1 * 22725) >> 15) - t0;
    t3  = ((s1 * 4520  - s7 * 22725) >> 15) - t1;
    t4  = t0 * 2 + t2;
    t5  = t1 * 2 + t3;
    t6  = t2 - t3;
    t7  = t3 * 2 + t6;
    t8  = (t6 * 11585) >> 14;
    t9  = (t7 * 11585) >> 14;
    tA  = (s2 * 8867 - s6 * 21407) >> 14;
    tB  = (s6 * 8867 + s2 * 21407) >> 14;
    tC  = (s0 >> 1) - (s4 >> 1);
    tD  = (s4 >> 1) * 2 + tC;
    tE  = tC - (tA >> 1);
    tF  = tD - (tB >> 1);
    t10 = tF - t5;
    t11 = tE - t8;
    t12 = tE + (tA >> 1) * 2 - t9;
    t13 = tF + (tB >> 1) * 2 - t4;

    blk[0 * 8] = t13 + t4 * 2;
    blk[1 * 8] = t12 + t9 * 2;
    blk[2 * 8] = t11 + t8 * 2;
    blk[3 * 8] = t10 + t5 * 2;
    blk[4 * 8] = t10;
    blk[5 * 8] = t11;
    blk[6 * 8] = t12;
    blk[7 * 8] = t13;
}

static inline void idct_row(int16_t *blk)
{
    int t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, tA, tB, tC, tD, tE, tF;
    int t10, t11, t12, t13;

    t0  =  (blk[3] * 19266 + blk[5] * 12873) >> 14;
    t1  =  (blk[5] * 19266 - blk[3] * 12873) >> 14;
    t2  = ((blk[7] * 4520  + blk[1] * 22725) >> 14) - t0;
    t3  = ((blk[1] * 4520  - blk[7] * 22725) >> 14) - t1;
    t4  = t0 * 2 + t2;
    t5  = t1 * 2 + t3;
    t6  = t2 - t3;
    t7  = t3 * 2 + t6;
    t8  = (t6 * 11585) >> 14;
    t9  = (t7 * 11585) >> 14;
    tA  = (blk[2] * 8867 - blk[6] * 21407) >> 14;
    tB  = (blk[6] * 8867 + blk[2] * 21407) >> 14;
    tC  = blk[0] - blk[4];
    tD  = blk[4] * 2 + tC;
    tE  = tC - tA;
    tF  = tD - tB;
    t10 = tF - t5;
    t11 = tE - t8;
    t12 = tE + tA * 2 - t9;
    t13 = tF + tB * 2 - t4;

    blk[0] = (t13 + t4 * 2 + 4) >> 3;
    blk[1] = (t12 + t9 * 2 + 4) >> 3;
    blk[2] = (t11 + t8 * 2 + 4) >> 3;
    blk[3] = (t10 + t5 * 2 + 4) >> 3;
    blk[4] = (t10          + 4) >> 3;
    blk[5] = (t11          + 4) >> 3;
    blk[6] = (t12          + 4) >> 3;
    blk[7] = (t13          + 4) >> 3;
}

static void hqx_idct_put(uint16_t *dst, ptrdiff_t stride,
                         int16_t *block, const uint8_t *quant)
{
    int i, j;

    for (i = 0; i < 8; i++)
        idct_col(block + i, quant + i);
    for (i = 0; i < 8; i++)
        idct_row(block + i * 8);

    for (i = 0; i < 8; i++) {
        for (j = 0; j < 8; j++) {
            int v = av_clip(block[j + i * 8] + 0x800, 0, 0xFFF);
            dst[j] = (v << 4) | (v >> 8);
        }
        dst += stride >> 1;
    }
}

av_cold void ff_hqxdsp_init(HQXDSPContext *c)
{
    c->idct_put = hqx_idct_put;
}