1
0
mirror of https://github.com/f4exb/sdrangel.git synced 2024-12-24 19:00:36 -05:00

DSDplus library: basic implementation with DMR and DSTAR

This commit is contained in:
f4exb 2016-04-10 23:36:03 +02:00
parent f6ac20cbb0
commit e48b825741
3 changed files with 170 additions and 1 deletions

View File

@ -1,6 +1,7 @@
project(dsdplus)
set(dsdplus_SOURCES
descramble.cpp
dmr_voice.cpp
dsd_decoder.cpp
dsd_filters.cpp
@ -11,6 +12,7 @@ set(dsdplus_SOURCES
)
set(dsdplus_HEADERS
descramble.h
dmr_voice.h
dsd_decoder.h
dsd_filters.h

View File

@ -17,6 +17,7 @@
#include <string.h>
#include "dstar.h"
#include "dsd_decoder.h"
#include "descramble.h"
namespace DSDplus
{
@ -151,6 +152,7 @@ void DSDDstar::init()
sync_missed = 0;
bitbuffer = 0;
m_symbolIndex = 0;
m_symbolIndexHD = 0;
}
void DSDDstar::initVoiceFrame()
@ -160,6 +162,9 @@ void DSDDstar::initVoiceFrame()
w = dW;
x = dX;
}
void DSDDstar::initDataFrame()
{
}
void DSDDstar::process()
{
@ -173,7 +178,15 @@ void DSDDstar::process()
}
else if (m_symbolIndex < 97) // data frame
{
if (m_symbolIndex == 72) {
initDataFrame();
}
processData();
}
else
{
m_dsdDecoder->m_fsmState = DSDDecoder::DSDLookForSync; // end
}
m_symbolIndex++;
@ -181,6 +194,16 @@ void DSDDstar::process()
void DSDDstar::processHD()
{
int dibit = m_dsdDecoder->getDibit(); // get dibit from symbol and store it in HD cache
radioheaderbuffer[m_symbolIndexHD] = dibit;
if (m_symbolIndexHD == 660-1)
{
dstar_header_decode();
m_dsdDecoder->m_fsmState = DSDDecoder::DSDprocessDSTAR; // go to DSTAR
}
m_symbolIndexHD++;
}
void DSDDstar::processVoice()
@ -223,7 +246,148 @@ void DSDDstar::processVoice()
void DSDDstar::processData()
{
bool terminate = false;
int dibit = m_dsdDecoder->getDibit(); // get dibit from symbol and store it in cache
m_dibitCache[m_symbolIndex] = dibit;
if (m_symbolIndex == 97-1) // last dibit in data frame
{
for (int i = 73; i < 97; i++)
{
int dibit = m_dibitCache[i];
bitbuffer <<= 1;
if (dibit == 1) {
bitbuffer |= 0x01;
}
if ((bitbuffer & 0x00FFFFFF) == 0x00AAB468)
{
// looking if we're slipping bits
if (i != 96)
{
fprintf(m_dsdDecoder->m_state.logfile, "sync after i=%d\n", i);
break;
}
}
}
slowdata[0] = (bitbuffer >> 16) & 0x000000FF;
slowdata[1] = (bitbuffer >> 8) & 0x000000FF;
slowdata[2] = (bitbuffer) & 0x000000FF;
slowdata[3] = 0;
if ((bitbuffer & 0x00FFFFFF) == 0x00AAB468)
{
//We got sync!
//printf("Sync on framecount = %d\n", framecount);
sync_missed = 0;
}
else if ((bitbuffer & 0x00FFFFFF) == 0xAAAAAA)
{
//End of transmission
printf("End of transmission\n");
terminate = true;
}
else if (framecount % 21 == 0)
{
printf("Missed sync on framecount = %d, value = %x/%x/%x\n",
framecount, slowdata[0], slowdata[1], slowdata[2]);
sync_missed++;
}
else if (framecount != 0 && (bitbuffer & 0x00FFFFFF) != 0x000000)
{
slowdata[0] ^= 0x70;
slowdata[1] ^= 0x4f;
slowdata[2] ^= 0x93;
//printf("unscrambled- %s",slowdata);
}
else if (framecount == 0)
{
//printf("never scrambled-%s\n",slowdata);
}
if (terminate)
{
m_dsdDecoder->m_fsmState = DSDDecoder::DSDLookForSync; // end
}
else if (sync_missed < 3)
{
m_symbolIndex = 0; // restart a frame sequence
framecount++;
}
else
{
m_dsdDecoder->m_fsmState = DSDDecoder::DSDLookForSync; // end
}
}
}
void DSDDstar::dstar_header_decode()
{
int radioheaderbuffer2[660];
unsigned char radioheader[41];
int octetcount, bitcount, loop;
unsigned char bit2octet[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
unsigned int FCSinheader;
unsigned int FCScalculated;
int len;
Descramble::scramble(radioheaderbuffer, radioheaderbuffer2);
Descramble::deinterleave(radioheaderbuffer2, radioheaderbuffer);
len = Descramble::FECdecoder(radioheaderbuffer, radioheaderbuffer2);
memset(radioheader, 0, 41);
// note we receive 330 bits, but we only use 328 of them (41 octets)
// bits 329 and 330 are unused
octetcount = 0;
bitcount = 0;
for (loop = 0; loop < 328; loop++)
{
if (radioheaderbuffer2[loop])
{
radioheader[octetcount] |= bit2octet[bitcount];
};
bitcount++;
// increase octetcounter and reset bitcounter every 8 bits
if (bitcount >= 8)
{
octetcount++;
bitcount = 0;
}
}
// print header
printf("\nDSTAR HEADER: ");
//printf("FLAG1: %02X - FLAG2: %02X - FLAG3: %02X\n", radioheader[0],
// radioheader[1], radioheader[2]);
printf("RPT 2: %c%c%c%c%c%c%c%c ", radioheader[3], radioheader[4],
radioheader[5], radioheader[6], radioheader[7], radioheader[8],
radioheader[9], radioheader[10]);
printf("RPT 1: %c%c%c%c%c%c%c%c ", radioheader[11], radioheader[12],
radioheader[13], radioheader[14], radioheader[15], radioheader[16],
radioheader[17], radioheader[18]);
printf("YOUR: %c%c%c%c%c%c%c%c ", radioheader[19], radioheader[20],
radioheader[21], radioheader[22], radioheader[23], radioheader[24],
radioheader[25], radioheader[26]);
printf("MY: %c%c%c%c%c%c%c%c/%c%c%c%c\n", radioheader[27], radioheader[28],
radioheader[29], radioheader[30], radioheader[31], radioheader[32],
radioheader[33], radioheader[34], radioheader[35], radioheader[36],
radioheader[37], radioheader[38]);
//FCSinheader = ((radioheader[39] << 8) | radioheader[40]) & 0xFFFF;
//FCScalculated = calc_fcs((unsigned char*) radioheader, 39);
//printf("Check sum = %04X ", FCSinheader);
//if (FCSinheader == FCScalculated) {
// printf("(OK)\n");
//} else {
// printf("(NOT OK- Calculated FCS = %04X)\n", FCScalculated);
//}; // end else - if
}
} // namespace DSDplus

View File

@ -34,11 +34,14 @@ public:
private:
void initVoiceFrame();
void initDataFrame();
void processVoice();
void processData();
void dstar_header_decode();
DSDDecoder *m_dsdDecoder;
int m_symbolIndex; //!< Current symbol index
int m_symbolIndex; //!< Current symbol index in non HD sequence
int m_symbolIndexHD; //!< Current symbol index in HD sequence
int m_dibitCache[97]; // has to handle a voice + data frame (97 dibits)
int m_dibitIndex; // index in dibit cache