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Handle the P25 low speed data.

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This commit is contained in:
Jonathan Naylor
2016-09-20 06:53:30 +01:00
parent c8cb7a5429
commit 34bf8f18a7
8 changed files with 105 additions and 32 deletions
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9
P25Control.cpp
View File

@@ -17,7 +17,6 @@
*/
#include "P25Control.h"
#include "P25LowSpeedData.h"
#include "P25Defines.h"
#include "Sync.h"
#include "Log.h"
@@ -58,7 +57,9 @@ m_nid(nac),
m_lastDUID(P25_DUID_TERM),
m_audio(),
m_rfData(),
m_netData()
m_netData(),
m_lsd(),
m_fp(NULL)
{
assert(display != NULL);
assert(lookup != NULL);
@@ -173,7 +174,7 @@ bool CP25Control::writeModem(unsigned char* data, unsigned int len)
m_rfData.processLDU1(data + 2U);
// Regenerate the Low Speed Data
CP25LowSpeedData::process(data + 2U);
m_lsd.process(data + 2U);
// Regenerate Audio
unsigned int errors = m_audio.process(data + 2U);
@@ -222,7 +223,7 @@ bool CP25Control::writeModem(unsigned char* data, unsigned int len)
m_rfData.processLDU2(data + 2U);
// Regenerate the Low Speed Data
CP25LowSpeedData::process(data + 2U);
m_lsd.process(data + 2U);
// Regenerate Audio
unsigned int errors = m_audio.process(data + 2U);

2
P25Control.h
View File

@@ -19,6 +19,7 @@
#if !defined(P25Control_H)
#define P25Control_H
#include "P25LowSpeedData.h"
#include "RingBuffer.h"
#include "P25Network.h"
#include "DMRLookup.h"
@@ -69,6 +70,7 @@ private:
CP25Audio m_audio;
CP25Data m_rfData;
CP25Data m_netData;
CP25LowSpeedData m_lsd;
FILE* m_fp;
void writeQueueRF(const unsigned char* data, unsigned int length);

71
P25LowSpeedData.cpp
View File

@@ -18,16 +18,81 @@
#include "P25LowSpeedData.h"
#include "P25Utils.h"
#include "Utils.h"
#include "Log.h"
#include <cstdio>
#include <cassert>
const unsigned int MAX_CCS_ERRS = 4U;
CP25LowSpeedData::CP25LowSpeedData()
{
}
CP25LowSpeedData::~CP25LowSpeedData()
{
}
void CP25LowSpeedData::process(unsigned char* data)
{
assert(data != NULL);
unsigned char lsd[4U];
CP25Utils::decode(data, lsd, 1546U, 1578U);
CUtils::dump(1U, "P25, Low Speed Data", lsd, 4U);
for (unsigned int a = 0x00U; a < 0x100U; a++) {
unsigned char ccs[2U];
ccs[0U] = a;
ccs[1U] = encode(ccs[0U]);
unsigned int errs = CP25Utils::compare(ccs, lsd + 0U, 2U);
if (errs < MAX_CCS_ERRS) {
lsd[0U] = ccs[0U];
lsd[1U] = ccs[1U];
break;
}
}
for (unsigned int a = 0x00U; a < 0x100U; a++) {
unsigned char ccs[2U];
ccs[0U] = a;
ccs[1U] = encode(ccs[0U]);
unsigned int errs = CP25Utils::compare(ccs, lsd + 2U, 2U);
if (errs < MAX_CCS_ERRS) {
lsd[2U] = ccs[0U];
lsd[3U] = ccs[1U];
break;
}
}
}
unsigned char CP25LowSpeedData::encode(unsigned char in)
{
unsigned char result = 0x00U;
if ((in & 0x01U) == 0x01U)
result ^= 0x39U;
if ((in & 0x02U) == 0x02U)
result ^= 0x72U;
if ((in & 0x04U) == 0x04U)
result ^= 0xE4U;
if ((in & 0x08U) == 0x08U)
result ^= 0xF1U;
if ((in & 0x10U) == 0x10U)
result ^= 0xDBU;
if ((in & 0x20U) == 0x20U)
result ^= 0x8FU;
if ((in & 0x40U) == 0x40U)
result ^= 0x27U;
if ((in & 0x80U) == 0x80U)
result ^= 0x4EU;
return result;
}

7
P25LowSpeedData.h
View File

@@ -21,7 +21,12 @@
class CP25LowSpeedData {
public:
static void process(unsigned char* data);
CP25LowSpeedData();
~CP25LowSpeedData();
void process(unsigned char* data);
unsigned char encode(const unsigned char in);
private:
};

27
P25NID.cpp
View File

@@ -88,31 +88,31 @@ bool CP25NID::decode(const unsigned char* data)
unsigned char nid[P25_NID_LENGTH_BYTES];
CP25Utils::decode(data, nid, 48U, 114U);
unsigned int errs = compare(nid, m_ldu1);
unsigned int errs = CP25Utils::compare(nid, m_ldu1, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_LDU1;
return true;
}
errs = compare(nid, m_ldu2);
errs = CP25Utils::compare(nid, m_ldu2, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_LDU2;
return true;
}
errs = compare(nid, m_term);
errs = CP25Utils::compare(nid, m_term, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_TERM;
return true;
}
errs = compare(nid, m_termlc);
errs = CP25Utils::compare(nid, m_termlc, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_TERM_LC;
return true;
}
errs = compare(nid, m_hdr);
errs = CP25Utils::compare(nid, m_hdr, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_HEADER;
return true;
@@ -150,20 +150,3 @@ unsigned char CP25NID::getDUID() const
{
return m_duid;
}
unsigned int CP25NID::compare(const unsigned char* nid1, const unsigned char* nid2) const
{
assert(nid1 != NULL);
assert(nid2 != NULL);
unsigned int errs = 0U;
for (unsigned int i = 0U; i < P25_NID_LENGTH_BYTES; i++) {
unsigned char v = nid1[i] ^ nid2[i];
while (v != 0U) {
v &= v - 1U;
errs++;
}
}
return errs;
}

2
P25NID.h
View File

@@ -37,8 +37,6 @@ private:
unsigned char* m_ldu2;
unsigned char* m_termlc;
unsigned char* m_term;
unsigned int compare(const unsigned char* nid1, const unsigned char* nid2) const;
};
#endif

17
P25Utils.cpp
View File

@@ -82,3 +82,20 @@ void CP25Utils::encode(const unsigned char* in, unsigned char* out, unsigned int
}
}
}
unsigned int CP25Utils::compare(const unsigned char* data1, const unsigned char* data2, unsigned int length)
{
assert(data1 != NULL);
assert(data2 != NULL);
unsigned int errs = 0U;
for (unsigned int i = 0U; i < length; i++) {
unsigned char v = data1[i] ^ data2[i];
while (v != 0U) {
v &= v - 1U;
errs++;
}
}
return errs;
}

2
P25Utils.h
View File

@@ -25,6 +25,8 @@ public:
static void decode(const unsigned char* in, unsigned char* out, unsigned int start, unsigned int stop);
static unsigned int compare(const unsigned char* data1, const unsigned char* data2, unsigned int length);
private:
};