1 /*
2 * TAK decoder
3 * Copyright (c) 2015 Paul B Mahol
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/attributes.h"
23 #include "takdsp.h"
24 #include "config.h"
25
decorrelate_ls(int32_t * p1,int32_t * p2,int length)26 static void decorrelate_ls(int32_t *p1, int32_t *p2, int length)
27 {
28 int i;
29
30 for (i = 0; i < length; i++) {
31 int32_t a = p1[i];
32 int32_t b = p2[i];
33 p2[i] = a + b;
34 }
35 }
36
decorrelate_sr(int32_t * p1,int32_t * p2,int length)37 static void decorrelate_sr(int32_t *p1, int32_t *p2, int length)
38 {
39 int i;
40
41 for (i = 0; i < length; i++) {
42 int32_t a = p1[i];
43 int32_t b = p2[i];
44 p1[i] = b - a;
45 }
46 }
47
decorrelate_sm(int32_t * p1,int32_t * p2,int length)48 static void decorrelate_sm(int32_t *p1, int32_t *p2, int length)
49 {
50 int i;
51
52 for (i = 0; i < length; i++) {
53 int32_t a = p1[i];
54 int32_t b = p2[i];
55 a -= b >> 1;
56 p1[i] = a;
57 p2[i] = a + b;
58 }
59 }
60
decorrelate_sf(int32_t * p1,int32_t * p2,int length,int dshift,int dfactor)61 static void decorrelate_sf(int32_t *p1, int32_t *p2, int length, int dshift, int dfactor)
62 {
63 int i;
64
65 for (i = 0; i < length; i++) {
66 int32_t a = p1[i];
67 int32_t b = p2[i];
68 b = (unsigned)(dfactor * (b >> dshift) + 128 >> 8) << dshift;
69 p1[i] = b - a;
70 }
71 }
72
ff_takdsp_init(TAKDSPContext * c)73 av_cold void ff_takdsp_init(TAKDSPContext *c)
74 {
75 c->decorrelate_ls = decorrelate_ls;
76 c->decorrelate_sr = decorrelate_sr;
77 c->decorrelate_sm = decorrelate_sm;
78 c->decorrelate_sf = decorrelate_sf;
79
80 if (ARCH_X86)
81 ff_takdsp_init_x86(c);
82 }
83