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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/*
* AC-3 DSP utils
* Copyright (c) 2011 Justin Ruggles
*
* 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 "libavutil/avassert.h"
#include "avcodec.h"
#include "ac3.h"
#include "ac3dsp.h"
#include "mathops.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, unsigned int len,
unsigned int shift)
{
uint32_t *src32 = (uint32_t *)src;
const uint32_t mask = ~(((1 << shift) - 1) << 16);
int i;
len >>= 1;
for (i = 0; i < len; i += 8) {
src32[i ] = (src32[i ] << shift) & mask;
src32[i+1] = (src32[i+1] << shift) & mask;
src32[i+2] = (src32[i+2] << shift) & mask;
src32[i+3] = (src32[i+3] << shift) & mask;
src32[i+4] = (src32[i+4] << shift) & mask;
src32[i+5] = (src32[i+5] << shift) & mask;
src32[i+6] = (src32[i+6] << shift) & mask;
src32[i+7] = (src32[i+7] << shift) & mask;
}
}
static void ac3_rshift_int32_c(int32_t *src, unsigned int len,
unsigned int shift)
{
do {
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
len -= 8;
} while (len > 0);
}
static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
{
const float scale = 1 << 24;
do {
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
*dst++ = lrintf(*src++ * scale);
len -= 8;
} while (len > 0);
}
static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
int start, int end,
int snr_offset, int floor,
const uint8_t *bap_tab, uint8_t *bap)
{
int bin, band, band_end;
/* special case, if snr offset is -960, set all bap's to zero */
if (snr_offset == -960) {
memset(bap, 0, AC3_MAX_COEFS);
return;
}
bin = start;
band = ff_ac3_bin_to_band_tab[start];
do {
int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
band_end = ff_ac3_band_start_tab[++band];
band_end = FFMIN(band_end, end);
for (; bin < band_end; bin++) {
int address = av_clip((psd[bin] - m) >> 5, 0, 63);
bap[bin] = bap_tab[address];
}
} while (end > band_end);
}
static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap,
int len)
{
while (len-- > 0)
mant_cnt[bap[len]]++;
}
DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = {
0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
};
static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
{
int blk, bap;
int bits = 0;
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
// bap=1 : 3 mantissas in 5 bits
bits += (mant_cnt[blk][1] / 3) * 5;
// bap=2 : 3 mantissas in 7 bits
// bap=4 : 2 mantissas in 7 bits
bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7;
// bap=3 : 1 mantissa in 3 bits
bits += mant_cnt[blk][3] * 3;
// bap=5 to 15 : get bits per mantissa from table
for (bap = 5; bap < 16; bap++)
bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap];
}
return bits;
}
static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
{
int i;
for (i = 0; i < nb_coefs; i++) {
int v = abs(coef[i]);
exp[i] = v ? 23 - av_log2(v) : 24;
}
}
static void ac3_downmix_c(float **samples, float (*matrix)[2],
int out_ch, int in_ch, int len)
{
int i, j;
float v0, v1;
if (out_ch == 2) {
for (i = 0; i < len; i++) {
v0 = v1 = 0.0f;
for (j = 0; j < in_ch; j++) {
v0 += samples[j][i] * matrix[j][0];
v1 += samples[j][i] * matrix[j][1];
}
samples[0][i] = v0;
samples[1][i] = v1;
}
} else if (out_ch == 1) {
for (i = 0; i < len; i++) {
v0 = 0.0f;
for (j = 0; j < in_ch; j++)
v0 += samples[j][i] * matrix[j][0];
samples[0][i] = v0;
}
}
}
static void apply_window_int16_c(int16_t *output, const int16_t *input,
const int16_t *window, unsigned int len)
{
int i;
int len2 = len >> 1;
for (i = 0; i < len2; i++) {
int16_t w = window[i];
output[i] = (MUL16(input[i], w) + (1 << 14)) >> 15;
output[len-i-1] = (MUL16(input[len-i-1], w) + (1 << 14)) >> 15;
}
}
av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
{
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_rshift_int32 = ac3_rshift_int32_c;
c->float_to_fixed24 = float_to_fixed24_c;
c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
c->update_bap_counts = ac3_update_bap_counts_c;
c->compute_mantissa_size = ac3_compute_mantissa_size_c;
c->extract_exponents = ac3_extract_exponents_c;
c->downmix = ac3_downmix_c;
c->apply_window_int16 = apply_window_int16_c;
if (ARCH_ARM)
ff_ac3dsp_init_arm(c, bit_exact);
if (ARCH_X86)
ff_ac3dsp_init_x86(c, bit_exact);
}
|
