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
232
233
234
|
/*
* Siren Encoder/Decoder library
*
* @author: Youness Alaoui <kakaroto@kakaroto.homelinux.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "siren7.h"
SirenDecoder Siren7_NewDecoder(int sample_rate) {
SirenDecoder decoder = (SirenDecoder) malloc(sizeof(struct stSirenDecoder));
decoder->sample_rate = sample_rate;
decoder->WavHeader.riff.RiffId = ME_TO_LE32(RIFF_ID);
decoder->WavHeader.riff.RiffSize = sizeof(PCMWavHeader) - 2*sizeof(int);
decoder->WavHeader.riff.RiffSize = ME_TO_LE32(decoder->WavHeader.riff.RiffSize);
decoder->WavHeader.WaveId = ME_TO_LE32(WAVE_ID);
decoder->WavHeader.FmtId = ME_TO_LE32(FMT__ID);
decoder->WavHeader.FmtSize = ME_TO_LE32(sizeof(FmtChunk));
decoder->WavHeader.fmt.Format = ME_TO_LE16(0x01);
decoder->WavHeader.fmt.Channels = ME_TO_LE16(1);
decoder->WavHeader.fmt.SampleRate = ME_TO_LE32(16000);
decoder->WavHeader.fmt.ByteRate = ME_TO_LE32(32000);
decoder->WavHeader.fmt.BlockAlign = ME_TO_LE16(2);
decoder->WavHeader.fmt.BitsPerSample = ME_TO_LE16(16);
decoder->WavHeader.FactId = ME_TO_LE32(FACT_ID);
decoder->WavHeader.FactSize = ME_TO_LE32(sizeof(int));
decoder->WavHeader.Samples = ME_TO_LE32(0);
decoder->WavHeader.DataId = ME_TO_LE32(DATA_ID);
decoder->WavHeader.DataSize = ME_TO_LE32(0);
memset(decoder->context, 0, sizeof(decoder->context));
memset(decoder->backup_frame, 0, sizeof(decoder->backup_frame));
decoder->dw1 = 1;
decoder->dw2 = 1;
decoder->dw3 = 1;
decoder->dw4 = 1;
siren_init();
return decoder;
}
void Siren7_CloseDecoder(SirenDecoder decoder) {
free(decoder);
}
int Siren7_DecodeFrame(SirenDecoder decoder, unsigned char *DataIn, unsigned char *DataOut) {
int number_of_coefs,
sample_rate_bits,
rate_control_bits,
rate_control_possibilities,
checksum_bits,
esf_adjustment,
scale_factor,
number_of_regions,
sample_rate_code,
bits_per_frame;
int decoded_sample_rate_code;
static int absolute_region_power_index[28] = {0};
static float decoder_standard_deviation[28] = {0};
static int power_categories[28] = {0};
static int category_balance[28] = {0};
int ChecksumTable[4] = {0x7F80, 0x7878, 0x6666, 0x5555};
int i, j;
int dwRes = 0;
int envelope_bits = 0;
int rate_control = 0;
int number_of_available_bits;
int number_of_valid_coefs;
int frame_error = 0;
int In[20];
float coefs[320];
float BufferOut[320];
int sum;
int checksum;
int calculated_checksum;
int idx;
int temp1;
int temp2;
for (i = 0; i < 20; i++)
#ifdef __BIG_ENDIAN__
In[i] = ((short *) DataIn)[i];
#else
In[i] = ((((short *) DataIn)[i] << 8) & 0xFF00) | ((((short *) DataIn)[i] >> 8) & 0x00FF);
#endif
dwRes = GetSirenCodecInfo(1, decoder->sample_rate, &number_of_coefs, &sample_rate_bits, &rate_control_bits, &rate_control_possibilities, &checksum_bits, &esf_adjustment, &scale_factor, &number_of_regions, &sample_rate_code, &bits_per_frame );
if (dwRes != 0)
return dwRes;
set_bitstream(In);
decoded_sample_rate_code = 0;
for (i = 0; i < sample_rate_bits; i++) {
decoded_sample_rate_code <<= 1;
decoded_sample_rate_code |= next_bit();
}
if (decoded_sample_rate_code != sample_rate_code)
return 7;
number_of_valid_coefs = region_size * number_of_regions;
number_of_available_bits = bits_per_frame - sample_rate_bits - checksum_bits ;
envelope_bits = decode_envelope(number_of_regions, decoder_standard_deviation, absolute_region_power_index, esf_adjustment);
number_of_available_bits -= envelope_bits;
for (i = 0; i < rate_control_bits; i++) {
rate_control <<= 1;
rate_control |= next_bit();
}
number_of_available_bits -= rate_control_bits;
categorize_regions(number_of_regions, number_of_available_bits, absolute_region_power_index, power_categories, category_balance);
for (i = 0; i < rate_control; i++) {
power_categories[category_balance[i]]++;
}
number_of_available_bits = decode_vector(decoder, number_of_regions, number_of_available_bits, decoder_standard_deviation, power_categories, coefs, scale_factor);
frame_error = 0;
if (number_of_available_bits > 0) {
for (i = 0; i < number_of_available_bits; i++) {
if (next_bit() == 0)
frame_error = 1;
}
} else if (number_of_available_bits < 0 && rate_control + 1 < rate_control_possibilities) {
frame_error |= 2;
}
for (i = 0; i < number_of_regions; i++) {
if (absolute_region_power_index[i] > 33 || absolute_region_power_index[i] < -31)
frame_error |= 4;
}
if (checksum_bits > 0) {
bits_per_frame >>= 4;
checksum = In[bits_per_frame - 1] & ((1 << checksum_bits) - 1);
In[bits_per_frame - 1] &= ~checksum;
sum = 0;
idx = 0;
do {
sum ^= (In[idx] & 0xFFFF) << (idx % 15);
} while (++idx < bits_per_frame);
sum = (sum >> 15) ^ (sum & 0x7FFF);
calculated_checksum = 0;
for (i = 0; i < 4; i++) {
temp1 = ChecksumTable[i] & sum;
for (j = 8; j > 0; j >>= 1) {
temp2 = temp1 >> j;
temp1 ^= temp2;
}
calculated_checksum <<= 1;
calculated_checksum |= temp1 & 1;
}
if (checksum != calculated_checksum)
frame_error |= 8;
}
if (frame_error != 0) {
for (i = 0; i < number_of_valid_coefs; i++) {
coefs[i] = decoder->backup_frame[i];
decoder->backup_frame[i] = 0;
}
} else {
for (i = 0; i < number_of_valid_coefs; i++)
decoder->backup_frame[i] = coefs[i];
}
for (i = number_of_valid_coefs; i < number_of_coefs; i++)
coefs[i] = 0;
dwRes = siren_rmlt_decode_samples(coefs, decoder->context, 320, BufferOut);
for (i = 0; i < 320; i++) {
if (BufferOut[i] > 32767.0)
((short *)DataOut)[i] = (short) ME_TO_LE16((short) 32767);
else if (BufferOut[i] <= -32768.0)
((short *)DataOut)[i] = (short) ME_TO_LE16((short) 32768);
else
((short *)DataOut)[i] = (short) ME_TO_LE16((short) BufferOut[i]);
}
decoder->WavHeader.Samples = ME_FROM_LE32(decoder->WavHeader.Samples);
decoder->WavHeader.Samples += 320;
decoder->WavHeader.Samples = ME_TO_LE32(decoder->WavHeader.Samples);
decoder->WavHeader.DataSize = ME_FROM_LE32(decoder->WavHeader.DataSize);
decoder->WavHeader.DataSize += 640;
decoder->WavHeader.DataSize = ME_TO_LE32(decoder->WavHeader.DataSize);
decoder->WavHeader.riff.RiffSize = ME_FROM_LE32(decoder->WavHeader.riff.RiffSize);
decoder->WavHeader.riff.RiffSize += 640;
decoder->WavHeader.riff.RiffSize = ME_TO_LE32(decoder->WavHeader.riff.RiffSize);
return 0;
}
|
