1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include <stdint.h>
20
21#include "config.h"
22#include "libavutil/attributes.h"
23#include "mathops.h"
24#include "huffyuvdsp.h"
25
26// 0x00010001 or 0x0001000100010001 or whatever, depending on the cpu's native arithmetic size
27#define pw_1 (ULONG_MAX / UINT16_MAX)
28
29static void add_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, int w){
30    long i;
31    unsigned long pw_lsb = (mask >> 1) * pw_1;
32    unsigned long pw_msb = pw_lsb +  pw_1;
33    for (i = 0; i <= w - (int)sizeof(long)/2; i += sizeof(long)/2) {
34        long a = *(long*)(src+i);
35        long b = *(long*)(dst+i);
36        *(long*)(dst+i) = ((a&pw_lsb) + (b&pw_lsb)) ^ ((a^b)&pw_msb);
37    }
38    for(; i<w; i++)
39        dst[i] = (dst[i] + src[i]) & mask;
40}
41
42static void add_hfyu_median_pred_int16_c(uint16_t *dst, const uint16_t *src, const uint16_t *diff, unsigned mask, int w, int *left, int *left_top){
43    int i;
44    uint16_t l, lt;
45
46    l  = *left;
47    lt = *left_top;
48
49    for(i=0; i<w; i++){
50        l  = (mid_pred(l, src[i], (l + src[i] - lt) & mask) + diff[i]) & mask;
51        lt = src[i];
52        dst[i] = l;
53    }
54
55    *left     = l;
56    *left_top = lt;
57}
58
59static void add_hfyu_left_pred_bgr32_c(uint8_t *dst, const uint8_t *src,
60                                       intptr_t w, uint8_t *left)
61{
62    int i;
63    uint8_t r = left[R], g = left[G], b = left[B], a = left[A];
64
65    for (i = 0; i < w; i++) {
66        b += src[4 * i + B];
67        g += src[4 * i + G];
68        r += src[4 * i + R];
69        a += src[4 * i + A];
70
71        dst[4 * i + B] = b;
72        dst[4 * i + G] = g;
73        dst[4 * i + R] = r;
74        dst[4 * i + A] = a;
75    }
76
77    left[B] = b;
78    left[G] = g;
79    left[R] = r;
80    left[A] = a;
81}
82
83av_cold void ff_huffyuvdsp_init(HuffYUVDSPContext *c, enum AVPixelFormat pix_fmt)
84{
85    c->add_int16 = add_int16_c;
86    c->add_hfyu_median_pred_int16 = add_hfyu_median_pred_int16_c;
87    c->add_hfyu_left_pred_bgr32 = add_hfyu_left_pred_bgr32_c;
88
89#if ARCH_X86
90    ff_huffyuvdsp_init_x86(c, pix_fmt);
91#endif
92}
93