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1da177e4 LT |
1 | /* $Id: isdn_audio.c,v 1.1.2.2 2004/01/12 22:37:18 keil Exp $ |
2 | * | |
3 | * Linux ISDN subsystem, audio conversion and compression (linklevel). | |
4 | * | |
5 | * Copyright 1994-1999 by Fritz Elfert (fritz@isdn4linux.de) | |
6 | * DTMF code (c) 1996 by Christian Mock (cm@kukuruz.ping.at) | |
7 | * Silence detection (c) 1998 by Armin Schindler (mac@gismo.telekom.de) | |
8 | * | |
9 | * This software may be used and distributed according to the terms | |
10 | * of the GNU General Public License, incorporated herein by reference. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/isdn.h> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
1da177e4 LT |
16 | #include "isdn_audio.h" |
17 | #include "isdn_common.h" | |
18 | ||
19 | char *isdn_audio_revision = "$Revision: 1.1.2.2 $"; | |
20 | ||
21 | /* | |
22 | * Misc. lookup-tables. | |
23 | */ | |
24 | ||
25 | /* ulaw -> signed 16-bit */ | |
26 | static short isdn_audio_ulaw_to_s16[] = | |
27 | { | |
28 | 0x8284, 0x8684, 0x8a84, 0x8e84, 0x9284, 0x9684, 0x9a84, 0x9e84, | |
29 | 0xa284, 0xa684, 0xaa84, 0xae84, 0xb284, 0xb684, 0xba84, 0xbe84, | |
30 | 0xc184, 0xc384, 0xc584, 0xc784, 0xc984, 0xcb84, 0xcd84, 0xcf84, | |
31 | 0xd184, 0xd384, 0xd584, 0xd784, 0xd984, 0xdb84, 0xdd84, 0xdf84, | |
32 | 0xe104, 0xe204, 0xe304, 0xe404, 0xe504, 0xe604, 0xe704, 0xe804, | |
33 | 0xe904, 0xea04, 0xeb04, 0xec04, 0xed04, 0xee04, 0xef04, 0xf004, | |
34 | 0xf0c4, 0xf144, 0xf1c4, 0xf244, 0xf2c4, 0xf344, 0xf3c4, 0xf444, | |
35 | 0xf4c4, 0xf544, 0xf5c4, 0xf644, 0xf6c4, 0xf744, 0xf7c4, 0xf844, | |
36 | 0xf8a4, 0xf8e4, 0xf924, 0xf964, 0xf9a4, 0xf9e4, 0xfa24, 0xfa64, | |
37 | 0xfaa4, 0xfae4, 0xfb24, 0xfb64, 0xfba4, 0xfbe4, 0xfc24, 0xfc64, | |
38 | 0xfc94, 0xfcb4, 0xfcd4, 0xfcf4, 0xfd14, 0xfd34, 0xfd54, 0xfd74, | |
39 | 0xfd94, 0xfdb4, 0xfdd4, 0xfdf4, 0xfe14, 0xfe34, 0xfe54, 0xfe74, | |
40 | 0xfe8c, 0xfe9c, 0xfeac, 0xfebc, 0xfecc, 0xfedc, 0xfeec, 0xfefc, | |
41 | 0xff0c, 0xff1c, 0xff2c, 0xff3c, 0xff4c, 0xff5c, 0xff6c, 0xff7c, | |
42 | 0xff88, 0xff90, 0xff98, 0xffa0, 0xffa8, 0xffb0, 0xffb8, 0xffc0, | |
43 | 0xffc8, 0xffd0, 0xffd8, 0xffe0, 0xffe8, 0xfff0, 0xfff8, 0x0000, | |
44 | 0x7d7c, 0x797c, 0x757c, 0x717c, 0x6d7c, 0x697c, 0x657c, 0x617c, | |
45 | 0x5d7c, 0x597c, 0x557c, 0x517c, 0x4d7c, 0x497c, 0x457c, 0x417c, | |
46 | 0x3e7c, 0x3c7c, 0x3a7c, 0x387c, 0x367c, 0x347c, 0x327c, 0x307c, | |
47 | 0x2e7c, 0x2c7c, 0x2a7c, 0x287c, 0x267c, 0x247c, 0x227c, 0x207c, | |
48 | 0x1efc, 0x1dfc, 0x1cfc, 0x1bfc, 0x1afc, 0x19fc, 0x18fc, 0x17fc, | |
49 | 0x16fc, 0x15fc, 0x14fc, 0x13fc, 0x12fc, 0x11fc, 0x10fc, 0x0ffc, | |
50 | 0x0f3c, 0x0ebc, 0x0e3c, 0x0dbc, 0x0d3c, 0x0cbc, 0x0c3c, 0x0bbc, | |
51 | 0x0b3c, 0x0abc, 0x0a3c, 0x09bc, 0x093c, 0x08bc, 0x083c, 0x07bc, | |
52 | 0x075c, 0x071c, 0x06dc, 0x069c, 0x065c, 0x061c, 0x05dc, 0x059c, | |
53 | 0x055c, 0x051c, 0x04dc, 0x049c, 0x045c, 0x041c, 0x03dc, 0x039c, | |
54 | 0x036c, 0x034c, 0x032c, 0x030c, 0x02ec, 0x02cc, 0x02ac, 0x028c, | |
55 | 0x026c, 0x024c, 0x022c, 0x020c, 0x01ec, 0x01cc, 0x01ac, 0x018c, | |
56 | 0x0174, 0x0164, 0x0154, 0x0144, 0x0134, 0x0124, 0x0114, 0x0104, | |
57 | 0x00f4, 0x00e4, 0x00d4, 0x00c4, 0x00b4, 0x00a4, 0x0094, 0x0084, | |
58 | 0x0078, 0x0070, 0x0068, 0x0060, 0x0058, 0x0050, 0x0048, 0x0040, | |
59 | 0x0038, 0x0030, 0x0028, 0x0020, 0x0018, 0x0010, 0x0008, 0x0000 | |
60 | }; | |
61 | ||
62 | /* alaw -> signed 16-bit */ | |
63 | static short isdn_audio_alaw_to_s16[] = | |
64 | { | |
65 | 0x13fc, 0xec04, 0x0144, 0xfebc, 0x517c, 0xae84, 0x051c, 0xfae4, | |
66 | 0x0a3c, 0xf5c4, 0x0048, 0xffb8, 0x287c, 0xd784, 0x028c, 0xfd74, | |
67 | 0x1bfc, 0xe404, 0x01cc, 0xfe34, 0x717c, 0x8e84, 0x071c, 0xf8e4, | |
68 | 0x0e3c, 0xf1c4, 0x00c4, 0xff3c, 0x387c, 0xc784, 0x039c, 0xfc64, | |
69 | 0x0ffc, 0xf004, 0x0104, 0xfefc, 0x417c, 0xbe84, 0x041c, 0xfbe4, | |
70 | 0x083c, 0xf7c4, 0x0008, 0xfff8, 0x207c, 0xdf84, 0x020c, 0xfdf4, | |
71 | 0x17fc, 0xe804, 0x018c, 0xfe74, 0x617c, 0x9e84, 0x061c, 0xf9e4, | |
72 | 0x0c3c, 0xf3c4, 0x0084, 0xff7c, 0x307c, 0xcf84, 0x030c, 0xfcf4, | |
73 | 0x15fc, 0xea04, 0x0164, 0xfe9c, 0x597c, 0xa684, 0x059c, 0xfa64, | |
74 | 0x0b3c, 0xf4c4, 0x0068, 0xff98, 0x2c7c, 0xd384, 0x02cc, 0xfd34, | |
75 | 0x1dfc, 0xe204, 0x01ec, 0xfe14, 0x797c, 0x8684, 0x07bc, 0xf844, | |
76 | 0x0f3c, 0xf0c4, 0x00e4, 0xff1c, 0x3c7c, 0xc384, 0x03dc, 0xfc24, | |
77 | 0x11fc, 0xee04, 0x0124, 0xfedc, 0x497c, 0xb684, 0x049c, 0xfb64, | |
78 | 0x093c, 0xf6c4, 0x0028, 0xffd8, 0x247c, 0xdb84, 0x024c, 0xfdb4, | |
79 | 0x19fc, 0xe604, 0x01ac, 0xfe54, 0x697c, 0x9684, 0x069c, 0xf964, | |
80 | 0x0d3c, 0xf2c4, 0x00a4, 0xff5c, 0x347c, 0xcb84, 0x034c, 0xfcb4, | |
81 | 0x12fc, 0xed04, 0x0134, 0xfecc, 0x4d7c, 0xb284, 0x04dc, 0xfb24, | |
82 | 0x09bc, 0xf644, 0x0038, 0xffc8, 0x267c, 0xd984, 0x026c, 0xfd94, | |
83 | 0x1afc, 0xe504, 0x01ac, 0xfe54, 0x6d7c, 0x9284, 0x06dc, 0xf924, | |
84 | 0x0dbc, 0xf244, 0x00b4, 0xff4c, 0x367c, 0xc984, 0x036c, 0xfc94, | |
85 | 0x0f3c, 0xf0c4, 0x00f4, 0xff0c, 0x3e7c, 0xc184, 0x03dc, 0xfc24, | |
86 | 0x07bc, 0xf844, 0x0008, 0xfff8, 0x1efc, 0xe104, 0x01ec, 0xfe14, | |
87 | 0x16fc, 0xe904, 0x0174, 0xfe8c, 0x5d7c, 0xa284, 0x05dc, 0xfa24, | |
88 | 0x0bbc, 0xf444, 0x0078, 0xff88, 0x2e7c, 0xd184, 0x02ec, 0xfd14, | |
89 | 0x14fc, 0xeb04, 0x0154, 0xfeac, 0x557c, 0xaa84, 0x055c, 0xfaa4, | |
90 | 0x0abc, 0xf544, 0x0058, 0xffa8, 0x2a7c, 0xd584, 0x02ac, 0xfd54, | |
91 | 0x1cfc, 0xe304, 0x01cc, 0xfe34, 0x757c, 0x8a84, 0x075c, 0xf8a4, | |
92 | 0x0ebc, 0xf144, 0x00d4, 0xff2c, 0x3a7c, 0xc584, 0x039c, 0xfc64, | |
93 | 0x10fc, 0xef04, 0x0114, 0xfeec, 0x457c, 0xba84, 0x045c, 0xfba4, | |
94 | 0x08bc, 0xf744, 0x0018, 0xffe8, 0x227c, 0xdd84, 0x022c, 0xfdd4, | |
95 | 0x18fc, 0xe704, 0x018c, 0xfe74, 0x657c, 0x9a84, 0x065c, 0xf9a4, | |
96 | 0x0cbc, 0xf344, 0x0094, 0xff6c, 0x327c, 0xcd84, 0x032c, 0xfcd4 | |
97 | }; | |
98 | ||
99 | /* alaw -> ulaw */ | |
100 | static char isdn_audio_alaw_to_ulaw[] = | |
101 | { | |
102 | 0xab, 0x2b, 0xe3, 0x63, 0x8b, 0x0b, 0xc9, 0x49, | |
103 | 0xba, 0x3a, 0xf6, 0x76, 0x9b, 0x1b, 0xd7, 0x57, | |
104 | 0xa3, 0x23, 0xdd, 0x5d, 0x83, 0x03, 0xc1, 0x41, | |
105 | 0xb2, 0x32, 0xeb, 0x6b, 0x93, 0x13, 0xcf, 0x4f, | |
106 | 0xaf, 0x2f, 0xe7, 0x67, 0x8f, 0x0f, 0xcd, 0x4d, | |
107 | 0xbe, 0x3e, 0xfe, 0x7e, 0x9f, 0x1f, 0xdb, 0x5b, | |
108 | 0xa7, 0x27, 0xdf, 0x5f, 0x87, 0x07, 0xc5, 0x45, | |
109 | 0xb6, 0x36, 0xef, 0x6f, 0x97, 0x17, 0xd3, 0x53, | |
110 | 0xa9, 0x29, 0xe1, 0x61, 0x89, 0x09, 0xc7, 0x47, | |
111 | 0xb8, 0x38, 0xf2, 0x72, 0x99, 0x19, 0xd5, 0x55, | |
112 | 0xa1, 0x21, 0xdc, 0x5c, 0x81, 0x01, 0xbf, 0x3f, | |
113 | 0xb0, 0x30, 0xe9, 0x69, 0x91, 0x11, 0xce, 0x4e, | |
114 | 0xad, 0x2d, 0xe5, 0x65, 0x8d, 0x0d, 0xcb, 0x4b, | |
115 | 0xbc, 0x3c, 0xfa, 0x7a, 0x9d, 0x1d, 0xd9, 0x59, | |
116 | 0xa5, 0x25, 0xde, 0x5e, 0x85, 0x05, 0xc3, 0x43, | |
117 | 0xb4, 0x34, 0xed, 0x6d, 0x95, 0x15, 0xd1, 0x51, | |
118 | 0xac, 0x2c, 0xe4, 0x64, 0x8c, 0x0c, 0xca, 0x4a, | |
119 | 0xbb, 0x3b, 0xf8, 0x78, 0x9c, 0x1c, 0xd8, 0x58, | |
120 | 0xa4, 0x24, 0xde, 0x5e, 0x84, 0x04, 0xc2, 0x42, | |
121 | 0xb3, 0x33, 0xec, 0x6c, 0x94, 0x14, 0xd0, 0x50, | |
122 | 0xb0, 0x30, 0xe8, 0x68, 0x90, 0x10, 0xce, 0x4e, | |
123 | 0xbf, 0x3f, 0xfe, 0x7e, 0xa0, 0x20, 0xdc, 0x5c, | |
124 | 0xa8, 0x28, 0xe0, 0x60, 0x88, 0x08, 0xc6, 0x46, | |
125 | 0xb7, 0x37, 0xf0, 0x70, 0x98, 0x18, 0xd4, 0x54, | |
126 | 0xaa, 0x2a, 0xe2, 0x62, 0x8a, 0x0a, 0xc8, 0x48, | |
127 | 0xb9, 0x39, 0xf4, 0x74, 0x9a, 0x1a, 0xd6, 0x56, | |
128 | 0xa2, 0x22, 0xdd, 0x5d, 0x82, 0x02, 0xc0, 0x40, | |
129 | 0xb1, 0x31, 0xea, 0x6a, 0x92, 0x12, 0xcf, 0x4f, | |
130 | 0xae, 0x2e, 0xe6, 0x66, 0x8e, 0x0e, 0xcc, 0x4c, | |
131 | 0xbd, 0x3d, 0xfc, 0x7c, 0x9e, 0x1e, 0xda, 0x5a, | |
132 | 0xa6, 0x26, 0xdf, 0x5f, 0x86, 0x06, 0xc4, 0x44, | |
133 | 0xb5, 0x35, 0xee, 0x6e, 0x96, 0x16, 0xd2, 0x52 | |
134 | }; | |
135 | ||
136 | /* ulaw -> alaw */ | |
137 | static char isdn_audio_ulaw_to_alaw[] = | |
138 | { | |
139 | 0xab, 0x55, 0xd5, 0x15, 0x95, 0x75, 0xf5, 0x35, | |
140 | 0xb5, 0x45, 0xc5, 0x05, 0x85, 0x65, 0xe5, 0x25, | |
141 | 0xa5, 0x5d, 0xdd, 0x1d, 0x9d, 0x7d, 0xfd, 0x3d, | |
142 | 0xbd, 0x4d, 0xcd, 0x0d, 0x8d, 0x6d, 0xed, 0x2d, | |
143 | 0xad, 0x51, 0xd1, 0x11, 0x91, 0x71, 0xf1, 0x31, | |
144 | 0xb1, 0x41, 0xc1, 0x01, 0x81, 0x61, 0xe1, 0x21, | |
145 | 0x59, 0xd9, 0x19, 0x99, 0x79, 0xf9, 0x39, 0xb9, | |
146 | 0x49, 0xc9, 0x09, 0x89, 0x69, 0xe9, 0x29, 0xa9, | |
147 | 0xd7, 0x17, 0x97, 0x77, 0xf7, 0x37, 0xb7, 0x47, | |
148 | 0xc7, 0x07, 0x87, 0x67, 0xe7, 0x27, 0xa7, 0xdf, | |
149 | 0x9f, 0x7f, 0xff, 0x3f, 0xbf, 0x4f, 0xcf, 0x0f, | |
150 | 0x8f, 0x6f, 0xef, 0x2f, 0x53, 0x13, 0x73, 0x33, | |
151 | 0xb3, 0x43, 0xc3, 0x03, 0x83, 0x63, 0xe3, 0x23, | |
152 | 0xa3, 0x5b, 0xdb, 0x1b, 0x9b, 0x7b, 0xfb, 0x3b, | |
153 | 0xbb, 0xbb, 0x4b, 0x4b, 0xcb, 0xcb, 0x0b, 0x0b, | |
154 | 0x8b, 0x8b, 0x6b, 0x6b, 0xeb, 0xeb, 0x2b, 0x2b, | |
155 | 0xab, 0x54, 0xd4, 0x14, 0x94, 0x74, 0xf4, 0x34, | |
156 | 0xb4, 0x44, 0xc4, 0x04, 0x84, 0x64, 0xe4, 0x24, | |
157 | 0xa4, 0x5c, 0xdc, 0x1c, 0x9c, 0x7c, 0xfc, 0x3c, | |
158 | 0xbc, 0x4c, 0xcc, 0x0c, 0x8c, 0x6c, 0xec, 0x2c, | |
159 | 0xac, 0x50, 0xd0, 0x10, 0x90, 0x70, 0xf0, 0x30, | |
160 | 0xb0, 0x40, 0xc0, 0x00, 0x80, 0x60, 0xe0, 0x20, | |
161 | 0x58, 0xd8, 0x18, 0x98, 0x78, 0xf8, 0x38, 0xb8, | |
162 | 0x48, 0xc8, 0x08, 0x88, 0x68, 0xe8, 0x28, 0xa8, | |
163 | 0xd6, 0x16, 0x96, 0x76, 0xf6, 0x36, 0xb6, 0x46, | |
164 | 0xc6, 0x06, 0x86, 0x66, 0xe6, 0x26, 0xa6, 0xde, | |
165 | 0x9e, 0x7e, 0xfe, 0x3e, 0xbe, 0x4e, 0xce, 0x0e, | |
166 | 0x8e, 0x6e, 0xee, 0x2e, 0x52, 0x12, 0x72, 0x32, | |
167 | 0xb2, 0x42, 0xc2, 0x02, 0x82, 0x62, 0xe2, 0x22, | |
168 | 0xa2, 0x5a, 0xda, 0x1a, 0x9a, 0x7a, 0xfa, 0x3a, | |
169 | 0xba, 0xba, 0x4a, 0x4a, 0xca, 0xca, 0x0a, 0x0a, | |
170 | 0x8a, 0x8a, 0x6a, 0x6a, 0xea, 0xea, 0x2a, 0x2a | |
171 | }; | |
172 | ||
173 | #define NCOEFF 8 /* number of frequencies to be analyzed */ | |
174 | #define DTMF_TRESH 4000 /* above this is dtmf */ | |
175 | #define SILENCE_TRESH 200 /* below this is silence */ | |
176 | #define AMP_BITS 9 /* bits per sample, reduced to avoid overflow */ | |
177 | #define LOGRP 0 | |
178 | #define HIGRP 1 | |
179 | ||
180 | /* For DTMF recognition: | |
181 | * 2 * cos(2 * PI * k / N) precalculated for all k | |
182 | */ | |
183 | static int cos2pik[NCOEFF] = | |
184 | { | |
185 | 55813, 53604, 51193, 48591, 38114, 33057, 25889, 18332 | |
186 | }; | |
187 | ||
188 | static char dtmf_matrix[4][4] = | |
189 | { | |
190 | {'1', '2', '3', 'A'}, | |
191 | {'4', '5', '6', 'B'}, | |
192 | {'7', '8', '9', 'C'}, | |
193 | {'*', '0', '#', 'D'} | |
194 | }; | |
195 | ||
196 | static inline void | |
197 | isdn_audio_tlookup(const u_char *table, u_char *buff, unsigned long n) | |
198 | { | |
199 | #ifdef __i386__ | |
200 | unsigned long d0, d1, d2, d3; | |
201 | __asm__ __volatile__( | |
202 | "cld\n" | |
203 | "1:\tlodsb\n\t" | |
204 | "xlatb\n\t" | |
205 | "stosb\n\t" | |
206 | "loop 1b\n\t" | |
207 | : "=&b"(d0), "=&c"(d1), "=&D"(d2), "=&S"(d3) | |
208 | : "0"((long) table), "1"(n), "2"((long) buff), "3"((long) buff) | |
209 | : "memory", "ax"); | |
210 | #else | |
211 | while (n--) | |
212 | *buff = table[*(unsigned char *)buff], buff++; | |
213 | #endif | |
214 | } | |
215 | ||
216 | void | |
217 | isdn_audio_ulaw2alaw(unsigned char *buff, unsigned long len) | |
218 | { | |
219 | isdn_audio_tlookup(isdn_audio_ulaw_to_alaw, buff, len); | |
220 | } | |
221 | ||
222 | void | |
223 | isdn_audio_alaw2ulaw(unsigned char *buff, unsigned long len) | |
224 | { | |
225 | isdn_audio_tlookup(isdn_audio_alaw_to_ulaw, buff, len); | |
226 | } | |
227 | ||
228 | /* | |
229 | * linear <-> adpcm conversion stuff | |
230 | * Most parts from the mgetty-package. | |
231 | * (C) by Gert Doering and Klaus Weidner | |
232 | * Used by permission of Gert Doering | |
233 | */ | |
234 | ||
235 | ||
236 | #define ZEROTRAP /* turn on the trap as per the MIL-STD */ | |
237 | #undef ZEROTRAP | |
238 | #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ | |
239 | #define CLIP 32635 | |
240 | ||
241 | static unsigned char | |
242 | isdn_audio_linear2ulaw(int sample) | |
243 | { | |
244 | static int exp_lut[256] = | |
245 | { | |
246 | 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, | |
247 | 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, | |
248 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
249 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, | |
250 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
251 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
252 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
253 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, | |
254 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
255 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
256 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
257 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
258 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
259 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
260 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, | |
261 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 | |
262 | }; | |
263 | int sign, | |
264 | exponent, | |
265 | mantissa; | |
266 | unsigned char ulawbyte; | |
267 | ||
268 | /* Get the sample into sign-magnitude. */ | |
269 | sign = (sample >> 8) & 0x80; /* set aside the sign */ | |
270 | if (sign != 0) | |
271 | sample = -sample; /* get magnitude */ | |
272 | if (sample > CLIP) | |
273 | sample = CLIP; /* clip the magnitude */ | |
274 | ||
275 | /* Convert from 16 bit linear to ulaw. */ | |
276 | sample = sample + BIAS; | |
277 | exponent = exp_lut[(sample >> 7) & 0xFF]; | |
278 | mantissa = (sample >> (exponent + 3)) & 0x0F; | |
279 | ulawbyte = ~(sign | (exponent << 4) | mantissa); | |
280 | #ifdef ZEROTRAP | |
281 | /* optional CCITT trap */ | |
282 | if (ulawbyte == 0) | |
283 | ulawbyte = 0x02; | |
284 | #endif | |
285 | return (ulawbyte); | |
286 | } | |
287 | ||
288 | ||
289 | static int Mx[3][8] = | |
290 | { | |
291 | {0x3800, 0x5600, 0, 0, 0, 0, 0, 0}, | |
292 | {0x399a, 0x3a9f, 0x4d14, 0x6607, 0, 0, 0, 0}, | |
293 | {0x3556, 0x3556, 0x399A, 0x3A9F, 0x4200, 0x4D14, 0x6607, 0x6607}, | |
294 | }; | |
295 | ||
296 | static int bitmask[9] = | |
297 | { | |
298 | 0, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff | |
299 | }; | |
300 | ||
301 | static int | |
302 | isdn_audio_get_bits(adpcm_state * s, unsigned char **in, int *len) | |
303 | { | |
304 | while (s->nleft < s->nbits) { | |
305 | int d = *((*in)++); | |
306 | (*len)--; | |
307 | s->word = (s->word << 8) | d; | |
308 | s->nleft += 8; | |
309 | } | |
310 | s->nleft -= s->nbits; | |
311 | return (s->word >> s->nleft) & bitmask[s->nbits]; | |
312 | } | |
313 | ||
314 | static void | |
315 | isdn_audio_put_bits(int data, int nbits, adpcm_state * s, | |
316 | unsigned char **out, int *len) | |
317 | { | |
318 | s->word = (s->word << nbits) | (data & bitmask[nbits]); | |
319 | s->nleft += nbits; | |
320 | while (s->nleft >= 8) { | |
321 | int d = (s->word >> (s->nleft - 8)); | |
322 | *(out[0]++) = d & 255; | |
323 | (*len)++; | |
324 | s->nleft -= 8; | |
325 | } | |
326 | } | |
327 | ||
328 | adpcm_state * | |
329 | isdn_audio_adpcm_init(adpcm_state * s, int nbits) | |
330 | { | |
331 | if (!s) | |
5cbded58 | 332 | s = kmalloc(sizeof(adpcm_state), GFP_ATOMIC); |
1da177e4 LT |
333 | if (s) { |
334 | s->a = 0; | |
335 | s->d = 5; | |
336 | s->word = 0; | |
337 | s->nleft = 0; | |
338 | s->nbits = nbits; | |
339 | } | |
340 | return s; | |
341 | } | |
342 | ||
343 | dtmf_state * | |
344 | isdn_audio_dtmf_init(dtmf_state * s) | |
345 | { | |
346 | if (!s) | |
5cbded58 | 347 | s = kmalloc(sizeof(dtmf_state), GFP_ATOMIC); |
1da177e4 LT |
348 | if (s) { |
349 | s->idx = 0; | |
350 | s->last = ' '; | |
351 | } | |
352 | return s; | |
353 | } | |
354 | ||
355 | /* | |
356 | * Decompression of adpcm data to a/u-law | |
357 | * | |
358 | */ | |
359 | ||
360 | int | |
361 | isdn_audio_adpcm2xlaw(adpcm_state * s, int fmt, unsigned char *in, | |
362 | unsigned char *out, int len) | |
363 | { | |
364 | int a = s->a; | |
365 | int d = s->d; | |
366 | int nbits = s->nbits; | |
367 | int olen = 0; | |
368 | ||
369 | while (len) { | |
370 | int e = isdn_audio_get_bits(s, &in, &len); | |
371 | int sign; | |
372 | ||
373 | if (nbits == 4 && e == 0) | |
374 | d = 4; | |
375 | sign = (e >> (nbits - 1)) ? -1 : 1; | |
376 | e &= bitmask[nbits - 1]; | |
377 | a += sign * ((e << 1) + 1) * d >> 1; | |
378 | if (d & 1) | |
379 | a++; | |
380 | if (fmt) | |
381 | *out++ = isdn_audio_ulaw_to_alaw[ | |
382 | isdn_audio_linear2ulaw(a << 2)]; | |
383 | else | |
384 | *out++ = isdn_audio_linear2ulaw(a << 2); | |
385 | olen++; | |
386 | d = (d * Mx[nbits - 2][e] + 0x2000) >> 14; | |
387 | if (d < 5) | |
388 | d = 5; | |
389 | } | |
390 | s->a = a; | |
391 | s->d = d; | |
392 | return olen; | |
393 | } | |
394 | ||
1da177e4 LT |
395 | int |
396 | isdn_audio_xlaw2adpcm(adpcm_state * s, int fmt, unsigned char *in, | |
397 | unsigned char *out, int len) | |
398 | { | |
399 | int a = s->a; | |
400 | int d = s->d; | |
401 | int nbits = s->nbits; | |
402 | int olen = 0; | |
403 | ||
404 | while (len--) { | |
405 | int e = 0, | |
406 | nmax = 1 << (nbits - 1); | |
407 | int sign, | |
408 | delta; | |
409 | ||
410 | if (fmt) | |
411 | delta = (isdn_audio_alaw_to_s16[*in++] >> 2) - a; | |
412 | else | |
413 | delta = (isdn_audio_ulaw_to_s16[*in++] >> 2) - a; | |
414 | if (delta < 0) { | |
415 | e = nmax; | |
416 | delta = -delta; | |
417 | } | |
418 | while (--nmax && delta > d) { | |
419 | delta -= d; | |
420 | e++; | |
421 | } | |
422 | if (nbits == 4 && ((e & 0x0f) == 0)) | |
423 | e = 8; | |
424 | isdn_audio_put_bits(e, nbits, s, &out, &olen); | |
425 | sign = (e >> (nbits - 1)) ? -1 : 1; | |
426 | e &= bitmask[nbits - 1]; | |
427 | ||
428 | a += sign * ((e << 1) + 1) * d >> 1; | |
429 | if (d & 1) | |
430 | a++; | |
431 | d = (d * Mx[nbits - 2][e] + 0x2000) >> 14; | |
432 | if (d < 5) | |
433 | d = 5; | |
434 | } | |
435 | s->a = a; | |
436 | s->d = d; | |
437 | return olen; | |
438 | } | |
439 | ||
440 | /* | |
441 | * Goertzel algorithm. | |
631dd1a8 | 442 | * See http://ptolemy.eecs.berkeley.edu/papers/96/dtmf_ict/ |
1da177e4 LT |
443 | * for more info. |
444 | * Result is stored into an sk_buff and queued up for later | |
445 | * evaluation. | |
446 | */ | |
447 | static void | |
448 | isdn_audio_goertzel(int *sample, modem_info * info) | |
449 | { | |
450 | int sk, | |
451 | sk1, | |
452 | sk2; | |
453 | int k, | |
454 | n; | |
455 | struct sk_buff *skb; | |
456 | int *result; | |
457 | ||
458 | skb = dev_alloc_skb(sizeof(int) * NCOEFF); | |
459 | if (!skb) { | |
460 | printk(KERN_WARNING | |
461 | "isdn_audio: Could not alloc DTMF result for ttyI%d\n", | |
462 | info->line); | |
463 | return; | |
464 | } | |
465 | result = (int *) skb_put(skb, sizeof(int) * NCOEFF); | |
466 | for (k = 0; k < NCOEFF; k++) { | |
467 | sk = sk1 = sk2 = 0; | |
468 | for (n = 0; n < DTMF_NPOINTS; n++) { | |
469 | sk = sample[n] + ((cos2pik[k] * sk1) >> 15) - sk2; | |
470 | sk2 = sk1; | |
471 | sk1 = sk; | |
472 | } | |
473 | /* Avoid overflows */ | |
474 | sk >>= 1; | |
475 | sk2 >>= 1; | |
476 | /* compute |X(k)|**2 */ | |
477 | /* report overflows. This should not happen. */ | |
478 | /* Comment this out if desired */ | |
479 | if (sk < -32768 || sk > 32767) | |
480 | printk(KERN_DEBUG | |
481 | "isdn_audio: dtmf goertzel overflow, sk=%d\n", sk); | |
482 | if (sk2 < -32768 || sk2 > 32767) | |
483 | printk(KERN_DEBUG | |
484 | "isdn_audio: dtmf goertzel overflow, sk2=%d\n", sk2); | |
485 | result[k] = | |
486 | ((sk * sk) >> AMP_BITS) - | |
487 | ((((cos2pik[k] * sk) >> 15) * sk2) >> AMP_BITS) + | |
488 | ((sk2 * sk2) >> AMP_BITS); | |
489 | } | |
490 | skb_queue_tail(&info->dtmf_queue, skb); | |
491 | isdn_timer_ctrl(ISDN_TIMER_MODEMREAD, 1); | |
492 | } | |
493 | ||
494 | void | |
495 | isdn_audio_eval_dtmf(modem_info * info) | |
496 | { | |
497 | struct sk_buff *skb; | |
498 | int *result; | |
499 | dtmf_state *s; | |
500 | int silence; | |
501 | int i; | |
502 | int di; | |
503 | int ch; | |
504 | int grp[2]; | |
505 | char what; | |
506 | char *p; | |
507 | int thresh; | |
508 | ||
509 | while ((skb = skb_dequeue(&info->dtmf_queue))) { | |
510 | result = (int *) skb->data; | |
511 | s = info->dtmf_state; | |
512 | grp[LOGRP] = grp[HIGRP] = -1; | |
513 | silence = 0; | |
514 | thresh = 0; | |
515 | for (i = 0; i < NCOEFF; i++) { | |
516 | if (result[i] > DTMF_TRESH) { | |
517 | if (result[i] > thresh) | |
518 | thresh = result[i]; | |
519 | } | |
520 | else if (result[i] < SILENCE_TRESH) | |
521 | silence++; | |
522 | } | |
523 | if (silence == NCOEFF) | |
524 | what = ' '; | |
525 | else { | |
526 | if (thresh > 0) { | |
527 | thresh = thresh >> 4; /* touchtones must match within 12 dB */ | |
528 | for (i = 0; i < NCOEFF; i++) { | |
529 | if (result[i] < thresh) | |
530 | continue; /* ignore */ | |
531 | /* good level found. This is allowed only one time per group */ | |
532 | if (i < NCOEFF / 2) { | |
533 | /* lowgroup*/ | |
534 | if (grp[LOGRP] >= 0) { | |
535 | // Bad. Another tone found. */ | |
536 | grp[LOGRP] = -1; | |
537 | break; | |
538 | } | |
539 | else | |
540 | grp[LOGRP] = i; | |
541 | } | |
542 | else { /* higroup */ | |
543 | if (grp[HIGRP] >= 0) { // Bad. Another tone found. */ | |
544 | grp[HIGRP] = -1; | |
545 | break; | |
546 | } | |
547 | else | |
548 | grp[HIGRP] = i - NCOEFF/2; | |
549 | } | |
550 | } | |
551 | if ((grp[LOGRP] >= 0) && (grp[HIGRP] >= 0)) { | |
552 | what = dtmf_matrix[grp[LOGRP]][grp[HIGRP]]; | |
553 | if (s->last != ' ' && s->last != '.') | |
554 | s->last = what; /* min. 1 non-DTMF between DTMF */ | |
555 | } else | |
556 | what = '.'; | |
557 | } | |
558 | else | |
559 | what = '.'; | |
560 | } | |
561 | if ((what != s->last) && (what != ' ') && (what != '.')) { | |
562 | printk(KERN_DEBUG "dtmf: tt='%c'\n", what); | |
563 | p = skb->data; | |
564 | *p++ = 0x10; | |
565 | *p = what; | |
566 | skb_trim(skb, 2); | |
567 | ISDN_AUDIO_SKB_DLECOUNT(skb) = 0; | |
568 | ISDN_AUDIO_SKB_LOCK(skb) = 0; | |
569 | di = info->isdn_driver; | |
570 | ch = info->isdn_channel; | |
571 | __skb_queue_tail(&dev->drv[di]->rpqueue[ch], skb); | |
572 | dev->drv[di]->rcvcount[ch] += 2; | |
573 | /* Schedule dequeuing */ | |
574 | if ((dev->modempoll) && (info->rcvsched)) | |
575 | isdn_timer_ctrl(ISDN_TIMER_MODEMREAD, 1); | |
576 | wake_up_interruptible(&dev->drv[di]->rcv_waitq[ch]); | |
577 | } else | |
578 | kfree_skb(skb); | |
579 | s->last = what; | |
580 | } | |
581 | } | |
582 | ||
583 | /* | |
584 | * Decode DTMF tones, queue result in separate sk_buf for | |
585 | * later examination. | |
586 | * Parameters: | |
587 | * s = pointer to state-struct. | |
588 | * buf = input audio data | |
589 | * len = size of audio data. | |
590 | * fmt = audio data format (0 = ulaw, 1 = alaw) | |
591 | */ | |
592 | void | |
593 | isdn_audio_calc_dtmf(modem_info * info, unsigned char *buf, int len, int fmt) | |
594 | { | |
595 | dtmf_state *s = info->dtmf_state; | |
596 | int i; | |
597 | int c; | |
598 | ||
599 | while (len) { | |
600 | c = DTMF_NPOINTS - s->idx; | |
601 | if (c > len) | |
602 | c = len; | |
603 | if (c <= 0) | |
604 | break; | |
605 | for (i = 0; i < c; i++) { | |
606 | if (fmt) | |
607 | s->buf[s->idx++] = | |
608 | isdn_audio_alaw_to_s16[*buf++] >> (15 - AMP_BITS); | |
609 | else | |
610 | s->buf[s->idx++] = | |
611 | isdn_audio_ulaw_to_s16[*buf++] >> (15 - AMP_BITS); | |
612 | } | |
613 | if (s->idx == DTMF_NPOINTS) { | |
614 | isdn_audio_goertzel(s->buf, info); | |
615 | s->idx = 0; | |
616 | } | |
617 | len -= c; | |
618 | } | |
619 | } | |
620 | ||
621 | silence_state * | |
622 | isdn_audio_silence_init(silence_state * s) | |
623 | { | |
624 | if (!s) | |
5cbded58 | 625 | s = kmalloc(sizeof(silence_state), GFP_ATOMIC); |
1da177e4 LT |
626 | if (s) { |
627 | s->idx = 0; | |
628 | s->state = 0; | |
629 | } | |
630 | return s; | |
631 | } | |
632 | ||
633 | void | |
634 | isdn_audio_calc_silence(modem_info * info, unsigned char *buf, int len, int fmt) | |
635 | { | |
636 | silence_state *s = info->silence_state; | |
637 | int i; | |
638 | signed char c; | |
639 | ||
640 | if (!info->emu.vpar[1]) return; | |
641 | ||
642 | for (i = 0; i < len; i++) { | |
643 | if (fmt) | |
644 | c = isdn_audio_alaw_to_ulaw[*buf++]; | |
645 | else | |
646 | c = *buf++; | |
647 | ||
648 | if (c > 0) c -= 128; | |
649 | c = abs(c); | |
650 | ||
651 | if (c > (info->emu.vpar[1] * 4)) { | |
652 | s->idx = 0; | |
653 | s->state = 1; | |
654 | } else { | |
655 | if (s->idx < 210000) s->idx++; | |
656 | } | |
657 | } | |
658 | } | |
659 | ||
660 | void | |
661 | isdn_audio_put_dle_code(modem_info * info, u_char code) | |
662 | { | |
663 | struct sk_buff *skb; | |
664 | int di; | |
665 | int ch; | |
666 | char *p; | |
667 | ||
668 | skb = dev_alloc_skb(2); | |
669 | if (!skb) { | |
670 | printk(KERN_WARNING | |
671 | "isdn_audio: Could not alloc skb for ttyI%d\n", | |
672 | info->line); | |
673 | return; | |
674 | } | |
675 | p = (char *) skb_put(skb, 2); | |
676 | p[0] = 0x10; | |
677 | p[1] = code; | |
678 | ISDN_AUDIO_SKB_DLECOUNT(skb) = 0; | |
679 | ISDN_AUDIO_SKB_LOCK(skb) = 0; | |
680 | di = info->isdn_driver; | |
681 | ch = info->isdn_channel; | |
682 | __skb_queue_tail(&dev->drv[di]->rpqueue[ch], skb); | |
683 | dev->drv[di]->rcvcount[ch] += 2; | |
684 | /* Schedule dequeuing */ | |
685 | if ((dev->modempoll) && (info->rcvsched)) | |
686 | isdn_timer_ctrl(ISDN_TIMER_MODEMREAD, 1); | |
687 | wake_up_interruptible(&dev->drv[di]->rcv_waitq[ch]); | |
688 | } | |
689 | ||
690 | void | |
691 | isdn_audio_eval_silence(modem_info * info) | |
692 | { | |
693 | silence_state *s = info->silence_state; | |
694 | char what; | |
695 | ||
696 | what = ' '; | |
697 | ||
698 | if (s->idx > (info->emu.vpar[2] * 800)) { | |
699 | s->idx = 0; | |
700 | if (!s->state) { /* silence from beginning of rec */ | |
701 | what = 's'; | |
702 | } else { | |
703 | what = 'q'; | |
704 | } | |
705 | } | |
706 | if ((what == 's') || (what == 'q')) { | |
707 | printk(KERN_DEBUG "ttyI%d: %s\n", info->line, | |
708 | (what=='s') ? "silence":"quiet"); | |
709 | isdn_audio_put_dle_code(info, what); | |
710 | } | |
711 | } |