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Add P_FCS checksum check for incoming header

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This commit is contained in:
Ed Gonzalez 2015-06-17 11:21:26 -05:00
parent 5eb520fcce
commit 13d4d64014
3 changed files with 87 additions and 25 deletions
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101
DSP_API/ThumbDV/dstar.c
View file

@ -141,6 +141,40 @@ static const unsigned int INTERLEAVE_TABLE[] = {
362, 389, 416, 443, 470, 497, 524, 551, 578, 605, 632, 659, 27, 55, 83, 111, 139,
167, 195, 223, 251, 279, 307, 335};
static const unsigned short ccittTab[] = {
0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf,
0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7,
0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e,
0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876,
0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd,
0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5,
0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c,
0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974,
0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb,
0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3,
0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a,
0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72,
0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9,
0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1,
0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738,
0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70,
0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7,
0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff,
0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036,
0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e,
0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5,
0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd,
0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134,
0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c,
0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3,
0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb,
0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232,
0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a,
0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1,
0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9,
0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330,
0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78};
void dstar_scramble(BOOL * in, BOOL * out, uint32 length, uint32 * scramble_count)
{
if ( out == NULL || in == NULL || scramble_count == NULL) {
@ -552,6 +586,20 @@ BOOL dstar_stateMachine(DSTAR_MACHINE machine, BOOL in_bit, unsigned char * ambe
// output("outLen = %d\n" ,outLen);
gmsk_bitsToBytes(decoded, bytes, outLen);
// thumbDV_dump("FEC: ", bytes, outLen/8);
uint32 i = 0;
dstar_pfcs pfcs;
pfcs.crc16 = 0xFFFF;
for ( i = 0 ; i < 312 ; i += 8) {
dstar_pfcsUpdate(&pfcs, decoded + i);
}
BOOL pfcs_match = FALSE;
pfcs_match = dstar_pfcsCheck(&pfcs, decoded + 312);
if ( pfcs_match ) {
output(ANSI_GREEN "P_FCS Mathces!\n" ANSI_WHITE);
} else {
output(ANSI_RED "P_FCS Does Not Match!\n" ANSI_WHITE);
}
dstar_processHeader(bytes, &machine->incoming_header);
@ -663,34 +711,43 @@ BOOL dstar_stateMachine(DSTAR_MACHINE machine, BOOL in_bit, unsigned char * ambe
return have_audio_packet;
}
void dstar_pfcsUpdate(DSTAR_PFCS pfcs, BOOL * bits )
{
unsigned char byte;
gmsk_bitsToByte(bits, &byte);
pfcs->crc16 = (uint16)pfcs->crc8[1] ^ ccittTab[ pfcs->crc8[0] ^ byte ];
}
void dstar_pfcsResult( DSTAR_PFCS pfcs, BOOL * bits )
{
pfcs->crc16 = ~pfcs->crc16;
unsigned char mask = 0x80;
uint32 i = 0;
for ( i = 0 ; i < 8 ; i++, mask >>= 1 ) {
bits[i + 0] = (pfcs->crc8[0] & mask) ? TRUE : FALSE;
}
mask = 0x80;
for ( i = 0 ; i < 8 ; i++ , mask >>= 1 ) {
bits[i + 8] = (pfcs->crc8[1] & mask) ? TRUE : FALSE;
}
}
BOOL dstar_pfcsCheck(DSTAR_PFCS pfcs, BOOL * bits )
{
uint32 i = 0;
BOOL sum[16];
dstar_pfcsResult(pfcs, sum);
for ( i = 0 ; i < 16 ; i++ ) {
if ( sum[i] != bits[i] ) {
return FALSE;
}
}
return TRUE;
}

9
DSP_API/ThumbDV/dstar.h
View file

@ -85,12 +85,19 @@ typedef struct _dstar_fec
int metric[4];
} dstar_fec, * DSTAR_FEC;
typedef union _dstar_pfcs
{
uint16 crc16;
uint8 crc8[2];
} dstar_pfcs, * DSTAR_PFCS;
DSTAR_MACHINE dstar_createMachine(void);
void dstar_destroyMachine(DSTAR_MACHINE machine);
BOOL dstar_stateMachine(DSTAR_MACHINE machine, BOOL in_bit, unsigned char * ambe_out, uint32 ambe_buf_len);
void dstar_pfcsUpdate(DSTAR_PFCS pfcs, BOOL * bits );
BOOL dstar_pfcsCheck(DSTAR_PFCS pfcs, BOOL * bits );
void dstar_FECTest(void);
void dstar_scramble(BOOL * in, BOOL * out, uint32 length, uint32 * scramble_count);

2
DSP_API/ThumbDV/gmsk_modem.c
View file

@ -307,10 +307,8 @@ uint32 gmsk_encode(GMSK_MOD mod, BOOL bit, float * buffer, unsigned int length)
for (i = 0; i < DSTAR_RADIO_BIT_LENGTH; i++) {
if (bit) {
//buffer[i] = -0.5f;//gmsk_FilterProcessSingle(mod->filter, -0.5f);
buffer[i] = gmsk_FilterProcessSingle(mod->filter, -0.5f);
} else {
//buffer[i] = 0.5f;//gmsk_FilterProcessSingle(mod->filter, 0.5f);
buffer[i] = gmsk_FilterProcessSingle(mod->filter, 0.5f);
}
}