Commit | Line | Data |
---|---|---|
3712b42d KK |
1 | /* |
2 | ||
3 | * l1oip_codec.c generic codec using lookup table | |
4 | * -> conversion from a-Law to u-Law | |
5 | * -> conversion from u-Law to a-Law | |
6 | * -> compression by reducing the number of sample resolution to 4 | |
7 | * | |
8 | * NOTE: It is not compatible with any standard codec like ADPCM. | |
9 | * | |
10 | * Author Andreas Eversberg (jolly@eversberg.eu) | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2, or (at your option) | |
15 | * any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, | |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
25 | ||
26 | */ | |
27 | ||
28 | /* | |
29 | ||
30 | How the codec works: | |
31 | -------------------- | |
32 | ||
33 | The volume is increased to increase the dynamic range of the audio signal. | |
34 | Each sample is converted to a-LAW with only 16 steps of level resolution. | |
35 | A pair of two samples are stored in one byte. | |
36 | ||
37 | The first byte is stored in the upper bits, the second byte is stored in the | |
38 | lower bits. | |
39 | ||
40 | To speed up compression and decompression, two lookup tables are formed: | |
41 | ||
42 | - 16 bits index for two samples (law encoded) with 8 bit compressed result. | |
43 | - 8 bits index for one compressed data with 16 bits decompressed result. | |
44 | ||
45 | NOTE: The bytes are handled as they are law-encoded. | |
46 | ||
47 | */ | |
48 | ||
49 | #include <linux/vmalloc.h> | |
50 | #include <linux/mISDNif.h> | |
a5355c27 | 51 | #include <linux/in.h> |
3712b42d | 52 | #include "core.h" |
5b834354 | 53 | #include "l1oip.h" |
3712b42d KK |
54 | |
55 | /* definitions of codec. don't use calculations, code may run slower. */ | |
56 | ||
57 | static u8 *table_com; | |
58 | static u16 *table_dec; | |
59 | ||
60 | ||
61 | /* alaw -> ulaw */ | |
62 | static u8 alaw_to_ulaw[256] = | |
63 | { | |
64 | 0xab, 0x2b, 0xe3, 0x63, 0x8b, 0x0b, 0xc9, 0x49, | |
65 | 0xba, 0x3a, 0xf6, 0x76, 0x9b, 0x1b, 0xd7, 0x57, | |
66 | 0xa3, 0x23, 0xdd, 0x5d, 0x83, 0x03, 0xc1, 0x41, | |
67 | 0xb2, 0x32, 0xeb, 0x6b, 0x93, 0x13, 0xcf, 0x4f, | |
68 | 0xaf, 0x2f, 0xe7, 0x67, 0x8f, 0x0f, 0xcd, 0x4d, | |
69 | 0xbe, 0x3e, 0xfe, 0x7e, 0x9f, 0x1f, 0xdb, 0x5b, | |
70 | 0xa7, 0x27, 0xdf, 0x5f, 0x87, 0x07, 0xc5, 0x45, | |
71 | 0xb6, 0x36, 0xef, 0x6f, 0x97, 0x17, 0xd3, 0x53, | |
72 | 0xa9, 0x29, 0xe1, 0x61, 0x89, 0x09, 0xc7, 0x47, | |
73 | 0xb8, 0x38, 0xf2, 0x72, 0x99, 0x19, 0xd5, 0x55, | |
74 | 0xa1, 0x21, 0xdc, 0x5c, 0x81, 0x01, 0xbf, 0x3f, | |
75 | 0xb0, 0x30, 0xe9, 0x69, 0x91, 0x11, 0xce, 0x4e, | |
76 | 0xad, 0x2d, 0xe5, 0x65, 0x8d, 0x0d, 0xcb, 0x4b, | |
77 | 0xbc, 0x3c, 0xfa, 0x7a, 0x9d, 0x1d, 0xd9, 0x59, | |
78 | 0xa5, 0x25, 0xde, 0x5e, 0x85, 0x05, 0xc3, 0x43, | |
79 | 0xb4, 0x34, 0xed, 0x6d, 0x95, 0x15, 0xd1, 0x51, | |
80 | 0xac, 0x2c, 0xe4, 0x64, 0x8c, 0x0c, 0xca, 0x4a, | |
81 | 0xbb, 0x3b, 0xf8, 0x78, 0x9c, 0x1c, 0xd8, 0x58, | |
82 | 0xa4, 0x24, 0xde, 0x5e, 0x84, 0x04, 0xc2, 0x42, | |
83 | 0xb3, 0x33, 0xec, 0x6c, 0x94, 0x14, 0xd0, 0x50, | |
84 | 0xb0, 0x30, 0xe8, 0x68, 0x90, 0x10, 0xce, 0x4e, | |
85 | 0xbf, 0x3f, 0xfe, 0x7e, 0xa0, 0x20, 0xdc, 0x5c, | |
86 | 0xa8, 0x28, 0xe0, 0x60, 0x88, 0x08, 0xc6, 0x46, | |
87 | 0xb7, 0x37, 0xf0, 0x70, 0x98, 0x18, 0xd4, 0x54, | |
88 | 0xaa, 0x2a, 0xe2, 0x62, 0x8a, 0x0a, 0xc8, 0x48, | |
89 | 0xb9, 0x39, 0xf4, 0x74, 0x9a, 0x1a, 0xd6, 0x56, | |
90 | 0xa2, 0x22, 0xdd, 0x5d, 0x82, 0x02, 0xc0, 0x40, | |
91 | 0xb1, 0x31, 0xea, 0x6a, 0x92, 0x12, 0xcf, 0x4f, | |
92 | 0xae, 0x2e, 0xe6, 0x66, 0x8e, 0x0e, 0xcc, 0x4c, | |
93 | 0xbd, 0x3d, 0xfc, 0x7c, 0x9e, 0x1e, 0xda, 0x5a, | |
94 | 0xa6, 0x26, 0xdf, 0x5f, 0x86, 0x06, 0xc4, 0x44, | |
95 | 0xb5, 0x35, 0xee, 0x6e, 0x96, 0x16, 0xd2, 0x52 | |
96 | }; | |
97 | ||
98 | /* ulaw -> alaw */ | |
99 | static u8 ulaw_to_alaw[256] = | |
100 | { | |
101 | 0xab, 0x55, 0xd5, 0x15, 0x95, 0x75, 0xf5, 0x35, | |
102 | 0xb5, 0x45, 0xc5, 0x05, 0x85, 0x65, 0xe5, 0x25, | |
103 | 0xa5, 0x5d, 0xdd, 0x1d, 0x9d, 0x7d, 0xfd, 0x3d, | |
104 | 0xbd, 0x4d, 0xcd, 0x0d, 0x8d, 0x6d, 0xed, 0x2d, | |
105 | 0xad, 0x51, 0xd1, 0x11, 0x91, 0x71, 0xf1, 0x31, | |
106 | 0xb1, 0x41, 0xc1, 0x01, 0x81, 0x61, 0xe1, 0x21, | |
107 | 0x59, 0xd9, 0x19, 0x99, 0x79, 0xf9, 0x39, 0xb9, | |
108 | 0x49, 0xc9, 0x09, 0x89, 0x69, 0xe9, 0x29, 0xa9, | |
109 | 0xd7, 0x17, 0x97, 0x77, 0xf7, 0x37, 0xb7, 0x47, | |
110 | 0xc7, 0x07, 0x87, 0x67, 0xe7, 0x27, 0xa7, 0xdf, | |
111 | 0x9f, 0x7f, 0xff, 0x3f, 0xbf, 0x4f, 0xcf, 0x0f, | |
112 | 0x8f, 0x6f, 0xef, 0x2f, 0x53, 0x13, 0x73, 0x33, | |
113 | 0xb3, 0x43, 0xc3, 0x03, 0x83, 0x63, 0xe3, 0x23, | |
114 | 0xa3, 0x5b, 0xdb, 0x1b, 0x9b, 0x7b, 0xfb, 0x3b, | |
115 | 0xbb, 0xbb, 0x4b, 0x4b, 0xcb, 0xcb, 0x0b, 0x0b, | |
116 | 0x8b, 0x8b, 0x6b, 0x6b, 0xeb, 0xeb, 0x2b, 0x2b, | |
117 | 0xab, 0x54, 0xd4, 0x14, 0x94, 0x74, 0xf4, 0x34, | |
118 | 0xb4, 0x44, 0xc4, 0x04, 0x84, 0x64, 0xe4, 0x24, | |
119 | 0xa4, 0x5c, 0xdc, 0x1c, 0x9c, 0x7c, 0xfc, 0x3c, | |
120 | 0xbc, 0x4c, 0xcc, 0x0c, 0x8c, 0x6c, 0xec, 0x2c, | |
121 | 0xac, 0x50, 0xd0, 0x10, 0x90, 0x70, 0xf0, 0x30, | |
122 | 0xb0, 0x40, 0xc0, 0x00, 0x80, 0x60, 0xe0, 0x20, | |
123 | 0x58, 0xd8, 0x18, 0x98, 0x78, 0xf8, 0x38, 0xb8, | |
124 | 0x48, 0xc8, 0x08, 0x88, 0x68, 0xe8, 0x28, 0xa8, | |
125 | 0xd6, 0x16, 0x96, 0x76, 0xf6, 0x36, 0xb6, 0x46, | |
126 | 0xc6, 0x06, 0x86, 0x66, 0xe6, 0x26, 0xa6, 0xde, | |
127 | 0x9e, 0x7e, 0xfe, 0x3e, 0xbe, 0x4e, 0xce, 0x0e, | |
128 | 0x8e, 0x6e, 0xee, 0x2e, 0x52, 0x12, 0x72, 0x32, | |
129 | 0xb2, 0x42, 0xc2, 0x02, 0x82, 0x62, 0xe2, 0x22, | |
130 | 0xa2, 0x5a, 0xda, 0x1a, 0x9a, 0x7a, 0xfa, 0x3a, | |
131 | 0xba, 0xba, 0x4a, 0x4a, 0xca, 0xca, 0x0a, 0x0a, | |
132 | 0x8a, 0x8a, 0x6a, 0x6a, 0xea, 0xea, 0x2a, 0x2a | |
133 | }; | |
134 | ||
135 | /* alaw -> 4bit compression */ | |
136 | static u8 alaw_to_4bit[256] = { | |
137 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
138 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
139 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
140 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
141 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
142 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
143 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
144 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
145 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
146 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
147 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0d, 0x02, | |
148 | 0x0e, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
149 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
150 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
151 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
152 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
153 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
154 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
155 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
156 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
157 | 0x0e, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
158 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x01, 0x0a, 0x05, | |
159 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
160 | 0x0d, 0x02, 0x09, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
161 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
162 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
163 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
164 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
165 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
166 | 0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04, | |
167 | 0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03, | |
168 | 0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04, | |
169 | }; | |
170 | ||
171 | /* 4bit -> alaw decompression */ | |
172 | static u8 _4bit_to_alaw[16] = { | |
173 | 0x5d, 0x51, 0xd9, 0xd7, 0x5f, 0x53, 0xa3, 0x4b, | |
174 | 0x2a, 0x3a, 0x22, 0x2e, 0x26, 0x56, 0x20, 0x2c, | |
175 | }; | |
176 | ||
177 | /* ulaw -> 4bit compression */ | |
178 | static u8 ulaw_to_4bit[256] = { | |
179 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
180 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
181 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
182 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, | |
183 | 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, | |
184 | 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, | |
185 | 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, | |
186 | 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, | |
187 | 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, | |
188 | 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, | |
189 | 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, | |
190 | 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, | |
191 | 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, | |
192 | 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, | |
193 | 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, | |
194 | 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, | |
195 | 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, | |
196 | 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, | |
197 | 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, | |
198 | 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, | |
199 | 0x0f, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, | |
200 | 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, | |
201 | 0x0e, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, | |
202 | 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, | |
203 | 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, | |
204 | 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0b, 0x0b, | |
205 | 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, | |
206 | 0x0b, 0x0b, 0x0b, 0x0b, 0x0a, 0x0a, 0x0a, 0x0a, | |
207 | 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, | |
208 | 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, | |
209 | 0x09, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, | |
210 | 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, | |
211 | }; | |
212 | ||
213 | /* 4bit -> ulaw decompression */ | |
214 | static u8 _4bit_to_ulaw[16] = { | |
215 | 0x11, 0x21, 0x31, 0x40, 0x4e, 0x5c, 0x68, 0x71, | |
216 | 0xfe, 0xef, 0xe7, 0xdb, 0xcd, 0xbf, 0xaf, 0x9f, | |
217 | }; | |
218 | ||
219 | ||
220 | /* | |
221 | * Compresses data to the result buffer | |
222 | * The result size must be at least half of the input buffer. | |
223 | * The number of samples also must be even! | |
224 | */ | |
225 | int | |
226 | l1oip_law_to_4bit(u8 *data, int len, u8 *result, u32 *state) | |
227 | { | |
228 | int ii, i = 0, o = 0; | |
229 | ||
230 | if (!len) | |
231 | return 0; | |
232 | ||
233 | /* send saved byte and first input byte */ | |
234 | if (*state) { | |
235 | *result++ = table_com[(((*state)<<8)&0xff00) | (*data++)]; | |
236 | len--; | |
237 | o++; | |
238 | } | |
239 | ||
240 | ii = len >> 1; | |
241 | ||
242 | while (i < ii) { | |
243 | *result++ = table_com[(data[0]<<8) | (data[1])]; | |
244 | data += 2; | |
245 | i++; | |
246 | o++; | |
247 | } | |
248 | ||
249 | /* if len has an odd number, we save byte for next call */ | |
250 | if (len & 1) | |
251 | *state = 0x100 + *data; | |
252 | else | |
253 | *state = 0; | |
254 | ||
255 | return o; | |
256 | } | |
257 | ||
258 | /* Decompress data to the result buffer | |
259 | * The result size must be the number of sample in packet. (2 * input data) | |
260 | * The number of samples in the result are even! | |
261 | */ | |
262 | int | |
263 | l1oip_4bit_to_law(u8 *data, int len, u8 *result) | |
264 | { | |
265 | int i = 0; | |
266 | u16 r; | |
267 | ||
268 | while (i < len) { | |
269 | r = table_dec[*data++]; | |
270 | *result++ = r>>8; | |
271 | *result++ = r; | |
272 | i++; | |
273 | } | |
274 | ||
275 | return len << 1; | |
276 | } | |
277 | ||
278 | ||
279 | /* | |
280 | * law conversion | |
281 | */ | |
282 | int | |
283 | l1oip_alaw_to_ulaw(u8 *data, int len, u8 *result) | |
284 | { | |
285 | int i = 0; | |
286 | ||
287 | while (i < len) { | |
288 | *result++ = alaw_to_ulaw[*data++]; | |
289 | i++; | |
290 | } | |
291 | ||
292 | return len; | |
293 | } | |
294 | ||
295 | int | |
296 | l1oip_ulaw_to_alaw(u8 *data, int len, u8 *result) | |
297 | { | |
298 | int i = 0; | |
299 | ||
300 | while (i < len) { | |
301 | *result++ = ulaw_to_alaw[*data++]; | |
302 | i++; | |
303 | } | |
304 | ||
305 | return len; | |
306 | } | |
307 | ||
308 | ||
309 | /* | |
310 | * generate/free compression and decompression table | |
311 | */ | |
312 | void | |
313 | l1oip_4bit_free(void) | |
314 | { | |
315 | if (table_dec) | |
316 | vfree(table_dec); | |
317 | if (table_com) | |
318 | vfree(table_com); | |
319 | table_com = NULL; | |
320 | table_dec = NULL; | |
321 | } | |
322 | ||
323 | int | |
324 | l1oip_4bit_alloc(int ulaw) | |
325 | { | |
326 | int i1, i2, c, sample; | |
327 | ||
328 | /* in case, it is called again */ | |
329 | if (table_dec) | |
330 | return 0; | |
331 | ||
332 | /* alloc conversion tables */ | |
333 | table_com = vmalloc(65536); | |
334 | table_dec = vmalloc(512); | |
24ec68fb | 335 | if (!table_com || !table_dec) { |
3712b42d KK |
336 | l1oip_4bit_free(); |
337 | return -ENOMEM; | |
338 | } | |
339 | memset(table_com, 0, 65536); | |
340 | memset(table_dec, 0, 512); | |
341 | /* generate compression table */ | |
342 | i1 = 0; | |
343 | while (i1 < 256) { | |
344 | if (ulaw) | |
345 | c = ulaw_to_4bit[i1]; | |
346 | else | |
347 | c = alaw_to_4bit[i1]; | |
348 | i2 = 0; | |
349 | while (i2 < 256) { | |
350 | table_com[(i1<<8) | i2] |= (c<<4); | |
351 | table_com[(i2<<8) | i1] |= c; | |
352 | i2++; | |
353 | } | |
354 | i1++; | |
355 | } | |
356 | ||
357 | /* generate decompression table */ | |
358 | i1 = 0; | |
359 | while (i1 < 16) { | |
360 | if (ulaw) | |
361 | sample = _4bit_to_ulaw[i1]; | |
362 | else | |
363 | sample = _4bit_to_alaw[i1]; | |
364 | i2 = 0; | |
365 | while (i2 < 16) { | |
366 | table_dec[(i1<<4) | i2] |= (sample<<8); | |
367 | table_dec[(i2<<4) | i1] |= sample; | |
368 | i2++; | |
369 | } | |
370 | i1++; | |
371 | } | |
372 | ||
373 | return 0; | |
374 | } | |
375 | ||
376 |