source: ntrip/trunk/BNC/src/RTCM3/bits.h@ 10583

Last change on this file since 10583 was 10551, checked in by stuerze, 3 months ago

minor changes

File size: 7.8 KB
Line 
1// Part of BNC, a utility for retrieving decoding and
2// converting GNSS data streams from NTRIP broadcasters.
3//
4// Copyright (C) 2015
5// German Federal Agency for Cartography and Geodesy (BKG)
6// http://www.bkg.bund.de
7// Alberding GmbH
8// http://www.alberding.eu
9//
10// Email: euref-ip@bkg.bund.de
11//
12// This program is free software; you can redistribute it and/or
13// modify it under the terms of the GNU General Public License
14// as published by the Free Software Foundation, version 2.
15//
16// This program is distributed in the hope that it will be useful,
17// but WITHOUT ANY WARRANTY; without even the implied warranty of
18// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19// GNU General Public License for more details.
20//
21// You should have received a copy of the GNU General Public License
22// along with this program; if not, write to the Free Software
23// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24
25#ifndef BITS_H
26#define BITS_H
27
28#define LOADBITS(a) { \
29 while((a) > numbits) { \
30 if(!size--) return false; \
31 bitfield = (bitfield<<8)|*(data++); \
32 numbits += 8; \
33 } \
34}
35
36/* extract bits from data stream
37 b = variable to store result, a = number of bits */
38#define GETBITS64(b, a) { \
39 if(((a) > 56) && ((a)-56) > numbits) { \
40 uint64_t x; \
41 GETBITS(x, 56) \
42 LOADBITS((a)-56) \
43 b = ((x<<((a)-56)) | (bitfield<<(sizeof(bitfield)*8-numbits)) \
44 >>(sizeof(bitfield)*8-((a)-56))); \
45 numbits -= ((a)-56); \
46 } \
47 else { \
48 GETBITS(b, a) \
49 } \
50}
51
52/* extract bits from data stream
53 b = variable to store result, a = number of bits */
54#define GETBITS(b, a) { \
55 LOADBITS(a) \
56 b = (bitfield<<(64-numbits))>>(64-(a)); \
57 numbits -= (a); \
58}
59
60/* extract bits from data stream
61 b = variable to store result, a = number of bits */
62#define GETBITSFACTOR(b, a, c) { \
63 LOADBITS(a) \
64 b = ((bitfield<<(sizeof(bitfield)*8-numbits))>>(sizeof(bitfield)*8-(a)))*(c); \
65 numbits -= (a); \
66}
67
68/* extract floating value from data stream
69 b = variable to store result, a = number of bits */
70#define GETFLOAT(b, a, c) { \
71 LOADBITS(a) \
72 b = ((double)((bitfield<<(64-numbits))>>(64-(a))))*(c); \
73 numbits -= (a); \
74}
75
76/* extract signed floating value from data stream
77 b = variable to store result, a = number of bits */
78#define GETFLOATSIGN(b, a, c) { \
79 LOADBITS(a) \
80 b = ((double)(((int64_t)(bitfield<<(64-numbits)))>>(64-(a))))*(c); \
81 numbits -= (a); \
82}
83
84/* extract bits from data stream
85 b = variable to store result, a = number of bits */
86#define GETBITSSIGN(b, a) { \
87 LOADBITS(a) \
88 b = ((int64_t)(bitfield<<(64-numbits)))>>(64-(a)); \
89 numbits -= (a); \
90}
91
92#define GETFLOATSIGNM(b, a, c) { \
93 int l; \
94 LOADBITS(a) \
95 l = (bitfield<<(64-numbits))>>(64-1); \
96 b = ((double)(((bitfield<<(64-(numbits-1))))>>(64-(a-1))))*(c); \
97 numbits -= (a); \
98 if(l) b *= -1.0; \
99}
100
101#define SKIPBITS(b) { LOADBITS(b) numbits -= (b); }
102
103/* extract byte-aligned byte from data stream,
104 b = variable to store size, s = variable to store string pointer */
105#define GETSTRING(b, s) { \
106 b = *(data++); \
107 s = (char *) data; \
108 data += b; \
109 size -= b+1; \
110}
111
112#define STARTDATA \
113 size_t ressize=0; \
114 char *blockstart=0; \
115 int numbits=0; \
116 uint64_t bitbuffer=0;
117
118
119#define STOREBITS \
120 while(numbits >= 8) { \
121 if(!size) return 0; \
122 *(buffer++) = bitbuffer>>(numbits-8); \
123 numbits -= 8; \
124 ++ressize; \
125 --size; \
126 }
127
128#define ADDBITS(a, b) { \
129 bitbuffer = (bitbuffer<<(a))|((b)&((1<<a)-1)); \
130 numbits += (a); \
131 STOREBITS \
132 }
133
134
135#define INITBLOCK \
136 numbits = 0; \
137 blockstart = buffer; \
138 ADDBITS(8, 0xD3) \
139 ADDBITS(6, 0) \
140 ADDBITS(10, 0)
141
142#define ENDBLOCK \
143 if(numbits) { ADDBITS((8-numbits), 0) } { \
144 int len = buffer-blockstart-3; \
145 blockstart[1] |= len>>8; \
146 blockstart[2] = len; \
147 if(len > 1023) \
148 return 0; \
149 len = CRC24(len+3, (const unsigned char *) blockstart); \
150 ADDBITS(24, len) \
151 }
152
153#define SCALEADDBITS(a, b, c) ADDBITS(a, (int64_t)(c > 0 ? b*c+0.5 : b*c-0.5))
154
155
156// RTCM3 CRS encoding
157//////////////////////////////////////////////////////////
158#define CRSTOINT(type, value) static_cast<type>(round(value))
159
160#define CRSADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
161 |(CRSTOINT(long long,b)&((1ULL<<a)-1)); \
162 numbits += (a); \
163 while(numbits >= 8) { \
164 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
165
166#define CRSADDBITSFLOAT(a,b,c) {long long i = CRSTOINT(long long,(b)/(c)); \
167 CRSADDBITS(a,i)};
168
169// RTCM3 GPS EPH encoding
170//////////////////////////////////////////////////////////
171#define GPSTOINT(type, value) static_cast<type>(round(value))
172
173#define GPSADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
174 |(GPSTOINT(long long,b)&((1ULL<<a)-1)); \
175 numbits += (a); \
176 while(numbits >= 8) { \
177 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
178
179#define GPSADDBITSFLOAT(a,b,c) {long long i = GPSTOINT(long long,(b)/(c)); \
180 GPSADDBITS(a,i)};
181
182// RTCM3 GLONASS EPH encoding
183//////////////////////////////////////////////////////////
184#define GLONASSTOINT(type, value) static_cast<type>(round(value))
185
186#define GLONASSADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
187 |(GLONASSTOINT(long long,b)&((1ULL<<(a))-1)); \
188 numbits += (a); \
189 while(numbits >= 8) { \
190 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
191
192#define GLONASSADDBITSFLOATM(a,b,c) {int s; long long i; \
193 if(b < 0.0) \
194 { \
195 s = 1; \
196 i = GLONASSTOINT(long long,(-b)/(c)); \
197 if(!i) s = 0; \
198 } \
199 else \
200 { \
201 s = 0; \
202 i = GLONASSTOINT(long long,(b)/(c)); \
203 } \
204 GLONASSADDBITS(1,s) \
205 GLONASSADDBITS(a-1,i)}
206
207// RTCM3 Galileo EPH encoding
208//////////////////////////////////////////////////////////
209#define GALILEOTOINT(type, value) static_cast<type>(round(value))
210
211#define GALILEOADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
212 |(GALILEOTOINT(long long,b)&((1LL<<a)-1)); \
213 numbits += (a); \
214 while(numbits >= 8) { \
215 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
216
217#define GALILEOADDBITSFLOAT(a,b,c) {long long i = GALILEOTOINT(long long,(b)/(c)); \
218 GALILEOADDBITS(a,i)};
219
220// RTCM3 BDS EPH encoding
221//////////////////////////////////////////////////////////
222#define BDSTOINT(type, value) static_cast<type>(round(value))
223
224#define BDSADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
225 |(BDSTOINT(long long,b)&((1ULL<<a)-1)); \
226 numbits += (a); \
227 while(numbits >= 8) { \
228 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
229
230#define BDSADDBITSFLOAT(a,b,c) {long long i = BDSTOINT(long long,(b)/(c)); \
231 BDSADDBITS(a,i)};
232
233// RTCM3 SBAS EPH encoding
234//////////////////////////////////////////////////////////
235#define SBASTOINT(type, value) static_cast<type>(round(value))
236
237#define SBASADDBITS(a, b) {bitbuffer = (bitbuffer<<(a)) \
238 |(SBASTOINT(long long,b)&((1ULL<<a)-1)); \
239 numbits += (a); \
240 while(numbits >= 8) { \
241 buffer[size++] = bitbuffer>>(numbits-8);numbits -= 8;}}
242
243#define SBASADDBITSFLOAT(a,b,c) {long long i = SBASTOINT(long long,(b)/(c)); \
244 SBASADDBITS(a,i)};
245
246#endif /* BITS_H */
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