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
|
/*
* 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
*/
/**
* @file
* Common code for Vorbis I encoder and decoder
* @author Denes Balatoni ( dbalatoni programozo hu )
*/
#define BITSTREAM_READER_LE
#include "avcodec.h"
#include "get_bits.h"
#include "vorbis.h"
/* Helper functions */
// x^(1/n)
unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
{
unsigned int ret = 0, i, j;
do {
++ret;
for (i = 0, j = ret; i < n - 1; i++)
j *= ret;
} while (j <= x);
return ret - 1;
}
// Generate vlc codes from vorbis huffman code lengths
// the two bits[p] > 32 checks should be redundant, all calling code should
// already ensure that, but since it allows overwriting the stack it seems
// reasonable to check redundantly.
int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
{
uint32_t exit_at_level[33] = { 404 };
unsigned i, j, p, code;
#ifdef DEBUG
GetBitContext gb;
#endif
for (p = 0; (bits[p] == 0) && (p < num); ++p)
;
if (p == num) {
// av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
return 0;
}
codes[p] = 0;
if (bits[p] > 32)
return 1;
for (i = 0; i < bits[p]; ++i)
exit_at_level[i+1] = 1 << i;
#ifdef DEBUG
av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
for (i = 0; i < bits[p]; ++i)
av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
av_log(NULL, AV_LOG_INFO, "\n");
#endif
++p;
for (; p < num; ++p) {
if (bits[p] > 32)
return 1;
if (bits[p] == 0)
continue;
// find corresponding exit(node which the tree can grow further from)
for (i = bits[p]; i > 0; --i)
if (exit_at_level[i])
break;
if (!i) // overspecified tree
return 1;
code = exit_at_level[i];
exit_at_level[i] = 0;
// construct code (append 0s to end) and introduce new exits
for (j = i + 1 ;j <= bits[p]; ++j)
exit_at_level[j] = code + (1 << (j - 1));
codes[p] = code;
#ifdef DEBUG
av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
for (i = 0; i < bits[p]; ++i)
av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
av_log(NULL, AV_LOG_INFO, "\n");
#endif
}
//no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
for (p = 1; p < 33; p++)
if (exit_at_level[p])
return 1;
return 0;
}
void ff_vorbis_ready_floor1_list(vorbis_floor1_entry * list, int values)
{
int i;
list[0].sort = 0;
list[1].sort = 1;
for (i = 2; i < values; i++) {
int j;
list[i].low = 0;
list[i].high = 1;
list[i].sort = i;
for (j = 2; j < i; j++) {
int tmp = list[j].x;
if (tmp < list[i].x) {
if (tmp > list[list[i].low].x)
list[i].low = j;
} else {
if (tmp < list[list[i].high].x)
list[i].high = j;
}
}
}
for (i = 0; i < values - 1; i++) {
int j;
for (j = i + 1; j < values; j++) {
if (list[list[i].sort].x > list[list[j].sort].x) {
int tmp = list[i].sort;
list[i].sort = list[j].sort;
list[j].sort = tmp;
}
}
}
}
static inline void render_line_unrolled(intptr_t x, intptr_t y, int x1,
intptr_t sy, int ady, int adx,
float *buf)
{
int err = -adx;
x -= x1 - 1;
buf += x1 - 1;
while (++x < 0) {
err += ady;
if (err >= 0) {
err += ady - adx;
y += sy;
buf[x++] = ff_vorbis_floor1_inverse_db_table[y];
}
buf[x] = ff_vorbis_floor1_inverse_db_table[y];
}
if (x <= 0) {
if (err + ady >= 0)
y += sy;
buf[x] = ff_vorbis_floor1_inverse_db_table[y];
}
}
static void render_line(int x0, int y0, int x1, int y1, float *buf)
{
int dy = y1 - y0;
int adx = x1 - x0;
int ady = FFABS(dy);
int sy = dy < 0 ? -1 : 1;
buf[x0] = ff_vorbis_floor1_inverse_db_table[y0];
if (ady*2 <= adx) { // optimized common case
render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
} else {
int base = dy / adx;
int x = x0;
int y = y0;
int err = -adx;
ady -= FFABS(base) * adx;
while (++x < x1) {
y += base;
err += ady;
if (err >= 0) {
err -= adx;
y += sy;
}
buf[x] = ff_vorbis_floor1_inverse_db_table[y];
}
}
}
void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
uint16_t *y_list, int *flag,
int multiplier, float *out, int samples)
{
int lx, ly, i;
lx = 0;
ly = y_list[0] * multiplier;
for (i = 1; i < values; i++) {
int pos = list[i].sort;
if (flag[pos]) {
int x1 = list[pos].x;
int y1 = y_list[pos] * multiplier;
if (lx < samples)
render_line(lx, ly, FFMIN(x1,samples), y1, out);
lx = x1;
ly = y1;
}
if (lx >= samples)
break;
}
if (lx < samples)
render_line(lx, ly, samples, ly, out);
}
|
