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
|
/*
* AC-3 DSP utils
* Copyright (c) 2011 Justin Ruggles
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "ac3dsp.h"
static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
{
int blk, i;
if (!num_reuse_blocks)
return;
for (i = 0; i < nb_coefs; i++) {
uint8_t min_exp = *exp;
uint8_t *exp1 = exp + 256;
for (blk = 0; blk < num_reuse_blocks; blk++) {
uint8_t next_exp = *exp1;
if (next_exp < min_exp)
min_exp = next_exp;
exp1 += 256;
}
*exp++ = min_exp;
}
}
static int ac3_max_msb_abs_int16_c(const int16_t *src, int len)
{
int i, v = 0;
for (i = 0; i < len; i++)
v |= abs(src[i]);
return v;
}
static void ac3_lshift_int16_c(int16_t *src, int len, unsigned int shift)
{
int i;
if (shift > 0) {
for (i = 0; i < len; i++)
src[i] <<= shift;
}
}
static void ac3_shift_int32_c(int32_t *src, int len, int shift)
{
int i;
if (shift > 0) {
for (i = 0; i < len; i++)
src[i] <<= shift;
} else if (shift < 0) {
shift = -shift;
for (i = 0; i < len; i++)
src[i] >>= shift;
}
}
av_cold void ff_ac3dsp_init(AC3DSPContext *c)
{
c->ac3_exponent_min = ac3_exponent_min_c;
c->ac3_max_msb_abs_int16 = ac3_max_msb_abs_int16_c;
c->ac3_lshift_int16 = ac3_lshift_int16_c;
c->ac3_shift_int32 = ac3_shift_int32_c;
if (HAVE_MMX)
ff_ac3dsp_init_x86(c);
}
|
