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Clean up dependencies.

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Move ModeA/C demodulator to demod_2000 (decoding stays in mode_ac.c)
Remove dependency on interactive.c in stats.c
faup1090 then doesn't need interactive.c at all.
This commit is contained in:
Oliver Jowett 2015-06-26 18:35:42 +01:00
parent 99dd290352
commit 5c2ec7106e
4 changed files with 284 additions and 285 deletions
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4
Makefile
View file

@ -33,11 +33,11 @@ dump1090: dump1090.o anet.o interactive.o mode_ac.o mode_s.o net_io.o crc.o demo
view1090: view1090.o anet.o interactive.o mode_ac.o mode_s.o net_io.o crc.o stats.o cpr.o icao_filter.o track.o util.o
$(CC) -g -o $@ $^ $(LIBS) $(LDFLAGS)
faup1090: faup1090.o anet.o interactive.o mode_ac.o mode_s.o net_io.o crc.o stats.o cpr.o icao_filter.o track.o util.o
faup1090: faup1090.o anet.o mode_ac.o mode_s.o net_io.o crc.o stats.o cpr.o icao_filter.o track.o util.o
$(CC) -g -o $@ $^ $(LIBS) $(LDFLAGS)
clean:
rm -f *.o dump1090 view1090 cprtests crctests
rm -f *.o dump1090 view1090 faup1090 cprtests crctests
test: cprtests
./cprtests

282
demod_2000.c
View file

@ -51,6 +51,288 @@
// Mode S 2.0MHz demodulator
//
// ===================== Mode A/C detection and decoding ===================
//
//
// This table is used to build the Mode A/C variable called ModeABits.Each
// bit period is inspected, and if it's value exceeds the threshold limit,
// then the value in this table is or-ed into ModeABits.
//
// At the end of message processing, ModeABits will be the decoded ModeA value.
//
// We can also flag noise in bits that should be zeros - the xx bits. Noise in
// these bits cause bits (31-16) in ModeABits to be set. Then at the end of message
// processing we can test for errors by looking at these bits.
//
uint32_t ModeABitTable[24] = {
0x00000000, // F1 = 1
0x00000010, // C1
0x00001000, // A1
0x00000020, // C2
0x00002000, // A2
0x00000040, // C4
0x00004000, // A4
0x40000000, // xx = 0 Set bit 30 if we see this high
0x00000100, // B1
0x00000001, // D1
0x00000200, // B2
0x00000002, // D2
0x00000400, // B4
0x00000004, // D4
0x00000000, // F2 = 1
0x08000000, // xx = 0 Set bit 27 if we see this high
0x04000000, // xx = 0 Set bit 26 if we see this high
0x00000080, // SPI
0x02000000, // xx = 0 Set bit 25 if we see this high
0x01000000, // xx = 0 Set bit 24 if we see this high
0x00800000, // xx = 0 Set bit 23 if we see this high
0x00400000, // xx = 0 Set bit 22 if we see this high
0x00200000, // xx = 0 Set bit 21 if we see this high
0x00100000, // xx = 0 Set bit 20 if we see this high
};
//
// This table is used to produce an error variable called ModeAErrs.Each
// inter-bit period is inspected, and if it's value falls outside of the
// expected range, then the value in this table is or-ed into ModeAErrs.
//
// At the end of message processing, ModeAErrs will indicate if we saw
// any inter-bit anomolies, and the bits that are set will show which
// bits had them.
//
uint32_t ModeAMidTable[24] = {
0x80000000, // F1 = 1 Set bit 31 if we see F1_C1 error
0x00000010, // C1 Set bit 4 if we see C1_A1 error
0x00001000, // A1 Set bit 12 if we see A1_C2 error
0x00000020, // C2 Set bit 5 if we see C2_A2 error
0x00002000, // A2 Set bit 13 if we see A2_C4 error
0x00000040, // C4 Set bit 6 if we see C3_A4 error
0x00004000, // A4 Set bit 14 if we see A4_xx error
0x40000000, // xx = 0 Set bit 30 if we see xx_B1 error
0x00000100, // B1 Set bit 8 if we see B1_D1 error
0x00000001, // D1 Set bit 0 if we see D1_B2 error
0x00000200, // B2 Set bit 9 if we see B2_D2 error
0x00000002, // D2 Set bit 1 if we see D2_B4 error
0x00000400, // B4 Set bit 10 if we see B4_D4 error
0x00000004, // D4 Set bit 2 if we see D4_F2 error
0x20000000, // F2 = 1 Set bit 29 if we see F2_xx error
0x08000000, // xx = 0 Set bit 27 if we see xx_xx error
0x04000000, // xx = 0 Set bit 26 if we see xx_SPI error
0x00000080, // SPI Set bit 15 if we see SPI_xx error
0x02000000, // xx = 0 Set bit 25 if we see xx_xx error
0x01000000, // xx = 0 Set bit 24 if we see xx_xx error
0x00800000, // xx = 0 Set bit 23 if we see xx_xx error
0x00400000, // xx = 0 Set bit 22 if we see xx_xx error
0x00200000, // xx = 0 Set bit 21 if we see xx_xx error
0x00100000, // xx = 0 Set bit 20 if we see xx_xx error
};
//
// The "off air" format is,,
// _F1_C1_A1_C2_A2_C4_A4_xx_B1_D1_B2_D2_B4_D4_F2_xx_xx_SPI_
//
// Bit spacing is 1.45uS, with 0.45uS high, and 1.00us low. This is a problem
// because we ase sampling at 2Mhz (500nS) so we are below Nyquist.
//
// The bit spacings are..
// F1 : 0.00,
// 1.45, 2.90, 4.35, 5.80, 7.25, 8.70,
// X : 10.15,
// : 11.60, 13.05, 14.50, 15.95, 17.40, 18.85,
// F2 : 20.30,
// X : 21.75, 23.20, 24.65
//
// This equates to the following sample point centers at 2Mhz.
// [ 0.0],
// [ 2.9], [ 5.8], [ 8.7], [11.6], [14.5], [17.4],
// [20.3],
// [23.2], [26.1], [29.0], [31.9], [34.8], [37.7]
// [40.6]
// [43.5], [46.4], [49.3]
//
// We know that this is a supposed to be a binary stream, so the signal
// should either be a 1 or a 0. Therefore, any energy above the noise level
// in two adjacent samples must be from the same pulse, so we can simply
// add the values together..
//
int detectModeA(uint16_t *m, struct modesMessage *mm)
{
int j, lastBitWasOne;
int ModeABits = 0;
int ModeAErrs = 0;
int byte, bit;
int thisSample, lastBit, lastSpace = 0;
int m0, m1, m2, m3, mPhase;
int n0, n1, n2 ,n3;
int F1_sig, F1_noise;
int F2_sig, F2_noise;
int fSig, fNoise, fLevel, fLoLo;
// m[0] contains the energy from 0 -> 499 nS
// m[1] contains the energy from 500 -> 999 nS
// m[2] contains the energy from 1000 -> 1499 nS
// m[3] contains the energy from 1500 -> 1999 nS
//
// We are looking for a Frame bit (F1) whose width is 450nS, followed by
// 1000nS of quiet.
//
// The width of the frame bit is 450nS, which is 90% of our sample rate.
// Therefore, in an ideal world, all the energy for the frame bit will be
// in a single sample, preceeded by (at least) one zero, and followed by
// two zeros, Best case we can look for ...
//
// 0 - 1 - 0 - 0
//
// However, our samples are not phase aligned, so some of the energy from
// each bit could be spread over two consecutive samples. Worst case is
// that we sample half in one bit, and half in the next. In that case,
// we're looking for
//
// 0 - 0.5 - 0.5 - 0.
m0 = m[0]; m1 = m[1];
if (m0 >= m1) // m1 *must* be bigger than m0 for this to be F1
{return (0);}
m2 = m[2]; m3 = m[3];
//
// if (m2 <= m0), then assume the sample bob on (Phase == 0), so don't look at m3
if ((m2 <= m0) || (m2 < m3))
{m3 = m2; m2 = m0;}
if ( (m3 >= m1) // m1 must be bigger than m3
|| (m0 > m2) // m2 can be equal to m0 if ( 0,1,0,0 )
|| (m3 > m2) ) // m2 can be equal to m3 if ( 0,1,0,0 )
{return (0);}
// m0 = noise
// m1 = noise + (signal * X))
// m2 = noise + (signal * (1-X))
// m3 = noise
//
// Hence, assuming all 4 samples have similar amounts of noise in them
// signal = (m1 + m2) - ((m0 + m3) * 2)
// noise = (m0 + m3) / 2
//
F1_sig = (m1 + m2) - ((m0 + m3) << 1);
F1_noise = (m0 + m3) >> 1;
if ( (F1_sig < MODEAC_MSG_SQUELCH_LEVEL) // minimum required F1 signal amplitude
|| (F1_sig < (F1_noise << 2)) ) // minimum allowable Sig/Noise ratio 4:1
{return (0);}
// If we get here then we have a potential F1, so look for an equally valid F2 20.3uS later
//
// Our F1 is centered somewhere between samples m[1] and m[2]. We can guestimate where F2 is
// by comparing the ratio of m1 and m2, and adding on 20.3 uS (40.6 samples)
//
mPhase = ((m2 * 20) / (m1 + m2));
byte = (mPhase + 812) / 20;
n0 = m[byte++]; n1 = m[byte++];
if (n0 >= n1) // n1 *must* be bigger than n0 for this to be F2
{return (0);}
n2 = m[byte++];
//
// if the sample bob on (Phase == 0), don't look at n3
//
if ((mPhase + 812) % 20)
{n3 = m[byte++];}
else
{n3 = n2; n2 = n0;}
if ( (n3 >= n1) // n1 must be bigger than n3
|| (n0 > n2) // n2 can be equal to n0 ( 0,1,0,0 )
|| (n3 > n2) ) // n2 can be equal to n3 ( 0,1,0,0 )
{return (0);}
F2_sig = (n1 + n2) - ((n0 + n3) << 1);
F2_noise = (n0 + n3) >> 1;
if ( (F2_sig < MODEAC_MSG_SQUELCH_LEVEL) // minimum required F2 signal amplitude
|| (F2_sig < (F2_noise << 2)) ) // maximum allowable Sig/Noise ratio 4:1
{return (0);}
fSig = (F1_sig + F2_sig) >> 1;
fNoise = (F1_noise + F2_noise) >> 1;
fLoLo = fNoise + (fSig >> 2); // 1/2
fLevel = fNoise + (fSig >> 1);
lastBitWasOne = 1;
lastBit = F1_sig;
//
// Now step by a half ModeA bit, 0.725nS, which is 1.45 samples, which is 29/20
// No need to do bit 0 because we've already selected it as a valid F1
// Do several bits past the SPI to increase error rejection
//
for (j = 1, mPhase += 29; j < 48; mPhase += 29, j ++)
{
byte = 1 + (mPhase / 20);
thisSample = m[byte] - fNoise;
if (mPhase % 20) // If the bit is split over two samples...
{thisSample += (m[byte+1] - fNoise);} // add in the second sample's energy
// If we're calculating a space value
if (j & 1)
{lastSpace = thisSample;}
else
{// We're calculating a new bit value
bit = j >> 1;
if (thisSample >= fLevel)
{// We're calculating a new bit value, and its a one
ModeABits |= ModeABitTable[bit--]; // or in the correct bit
if (lastBitWasOne)
{ // This bit is one, last bit was one, so check the last space is somewhere less than one
if ( (lastSpace >= (thisSample>>1)) || (lastSpace >= lastBit) )
{ModeAErrs |= ModeAMidTable[bit];}
}
else
{// This bit,is one, last bit was zero, so check the last space is somewhere less than one
if (lastSpace >= (thisSample >> 1))
{ModeAErrs |= ModeAMidTable[bit];}
}
lastBitWasOne = 1;
}
else
{// We're calculating a new bit value, and its a zero
if (lastBitWasOne)
{ // This bit is zero, last bit was one, so check the last space is somewhere in between
if (lastSpace >= lastBit)
{ModeAErrs |= ModeAMidTable[bit];}
}
else
{// This bit,is zero, last bit was zero, so check the last space is zero too
if (lastSpace >= fLoLo)
{ModeAErrs |= ModeAMidTable[bit];}
}
lastBitWasOne = 0;
}
lastBit = (thisSample >> 1);
}
}
//
// Output format is : 00:A4:A2:A1:00:B4:B2:B1:00:C4:C2:C1:00:D4:D2:D1
//
if ((ModeABits < 3) || (ModeABits & 0xFFFF8808) || (ModeAErrs) )
{return (ModeABits = 0);}
mm->signalLevel = (fSig + fNoise) * (fSig + fNoise) / MAX_POWER;
return ModeABits;
}
// ============================== Debugging =================================
//
// Helper function for dumpMagnitudeVector().

281
mode_ac.c
View file

@ -30,287 +30,6 @@
#include "dump1090.h"
//
// ===================== Mode A/C detection and decoding ===================
//
//
// This table is used to build the Mode A/C variable called ModeABits.Each
// bit period is inspected, and if it's value exceeds the threshold limit,
// then the value in this table is or-ed into ModeABits.
//
// At the end of message processing, ModeABits will be the decoded ModeA value.
//
// We can also flag noise in bits that should be zeros - the xx bits. Noise in
// these bits cause bits (31-16) in ModeABits to be set. Then at the end of message
// processing we can test for errors by looking at these bits.
//
uint32_t ModeABitTable[24] = {
0x00000000, // F1 = 1
0x00000010, // C1
0x00001000, // A1
0x00000020, // C2
0x00002000, // A2
0x00000040, // C4
0x00004000, // A4
0x40000000, // xx = 0 Set bit 30 if we see this high
0x00000100, // B1
0x00000001, // D1
0x00000200, // B2
0x00000002, // D2
0x00000400, // B4
0x00000004, // D4
0x00000000, // F2 = 1
0x08000000, // xx = 0 Set bit 27 if we see this high
0x04000000, // xx = 0 Set bit 26 if we see this high
0x00000080, // SPI
0x02000000, // xx = 0 Set bit 25 if we see this high
0x01000000, // xx = 0 Set bit 24 if we see this high
0x00800000, // xx = 0 Set bit 23 if we see this high
0x00400000, // xx = 0 Set bit 22 if we see this high
0x00200000, // xx = 0 Set bit 21 if we see this high
0x00100000, // xx = 0 Set bit 20 if we see this high
};
//
// This table is used to produce an error variable called ModeAErrs.Each
// inter-bit period is inspected, and if it's value falls outside of the
// expected range, then the value in this table is or-ed into ModeAErrs.
//
// At the end of message processing, ModeAErrs will indicate if we saw
// any inter-bit anomolies, and the bits that are set will show which
// bits had them.
//
uint32_t ModeAMidTable[24] = {
0x80000000, // F1 = 1 Set bit 31 if we see F1_C1 error
0x00000010, // C1 Set bit 4 if we see C1_A1 error
0x00001000, // A1 Set bit 12 if we see A1_C2 error
0x00000020, // C2 Set bit 5 if we see C2_A2 error
0x00002000, // A2 Set bit 13 if we see A2_C4 error
0x00000040, // C4 Set bit 6 if we see C3_A4 error
0x00004000, // A4 Set bit 14 if we see A4_xx error
0x40000000, // xx = 0 Set bit 30 if we see xx_B1 error
0x00000100, // B1 Set bit 8 if we see B1_D1 error
0x00000001, // D1 Set bit 0 if we see D1_B2 error
0x00000200, // B2 Set bit 9 if we see B2_D2 error
0x00000002, // D2 Set bit 1 if we see D2_B4 error
0x00000400, // B4 Set bit 10 if we see B4_D4 error
0x00000004, // D4 Set bit 2 if we see D4_F2 error
0x20000000, // F2 = 1 Set bit 29 if we see F2_xx error
0x08000000, // xx = 0 Set bit 27 if we see xx_xx error
0x04000000, // xx = 0 Set bit 26 if we see xx_SPI error
0x00000080, // SPI Set bit 15 if we see SPI_xx error
0x02000000, // xx = 0 Set bit 25 if we see xx_xx error
0x01000000, // xx = 0 Set bit 24 if we see xx_xx error
0x00800000, // xx = 0 Set bit 23 if we see xx_xx error
0x00400000, // xx = 0 Set bit 22 if we see xx_xx error
0x00200000, // xx = 0 Set bit 21 if we see xx_xx error
0x00100000, // xx = 0 Set bit 20 if we see xx_xx error
};
//
// The "off air" format is,,
// _F1_C1_A1_C2_A2_C4_A4_xx_B1_D1_B2_D2_B4_D4_F2_xx_xx_SPI_
//
// Bit spacing is 1.45uS, with 0.45uS high, and 1.00us low. This is a problem
// because we ase sampling at 2Mhz (500nS) so we are below Nyquist.
//
// The bit spacings are..
// F1 : 0.00,
// 1.45, 2.90, 4.35, 5.80, 7.25, 8.70,
// X : 10.15,
// : 11.60, 13.05, 14.50, 15.95, 17.40, 18.85,
// F2 : 20.30,
// X : 21.75, 23.20, 24.65
//
// This equates to the following sample point centers at 2Mhz.
// [ 0.0],
// [ 2.9], [ 5.8], [ 8.7], [11.6], [14.5], [17.4],
// [20.3],
// [23.2], [26.1], [29.0], [31.9], [34.8], [37.7]
// [40.6]
// [43.5], [46.4], [49.3]
//
// We know that this is a supposed to be a binary stream, so the signal
// should either be a 1 or a 0. Therefore, any energy above the noise level
// in two adjacent samples must be from the same pulse, so we can simply
// add the values together..
//
int detectModeA(uint16_t *m, struct modesMessage *mm)
{
int j, lastBitWasOne;
int ModeABits = 0;
int ModeAErrs = 0;
int byte, bit;
int thisSample, lastBit, lastSpace = 0;
int m0, m1, m2, m3, mPhase;
int n0, n1, n2 ,n3;
int F1_sig, F1_noise;
int F2_sig, F2_noise;
int fSig, fNoise, fLevel, fLoLo;
// m[0] contains the energy from 0 -> 499 nS
// m[1] contains the energy from 500 -> 999 nS
// m[2] contains the energy from 1000 -> 1499 nS
// m[3] contains the energy from 1500 -> 1999 nS
//
// We are looking for a Frame bit (F1) whose width is 450nS, followed by
// 1000nS of quiet.
//
// The width of the frame bit is 450nS, which is 90% of our sample rate.
// Therefore, in an ideal world, all the energy for the frame bit will be
// in a single sample, preceeded by (at least) one zero, and followed by
// two zeros, Best case we can look for ...
//
// 0 - 1 - 0 - 0
//
// However, our samples are not phase aligned, so some of the energy from
// each bit could be spread over two consecutive samples. Worst case is
// that we sample half in one bit, and half in the next. In that case,
// we're looking for
//
// 0 - 0.5 - 0.5 - 0.
m0 = m[0]; m1 = m[1];
if (m0 >= m1) // m1 *must* be bigger than m0 for this to be F1
{return (0);}
m2 = m[2]; m3 = m[3];
//
// if (m2 <= m0), then assume the sample bob on (Phase == 0), so don't look at m3
if ((m2 <= m0) || (m2 < m3))
{m3 = m2; m2 = m0;}
if ( (m3 >= m1) // m1 must be bigger than m3
|| (m0 > m2) // m2 can be equal to m0 if ( 0,1,0,0 )
|| (m3 > m2) ) // m2 can be equal to m3 if ( 0,1,0,0 )
{return (0);}
// m0 = noise
// m1 = noise + (signal * X))
// m2 = noise + (signal * (1-X))
// m3 = noise
//
// Hence, assuming all 4 samples have similar amounts of noise in them
// signal = (m1 + m2) - ((m0 + m3) * 2)
// noise = (m0 + m3) / 2
//
F1_sig = (m1 + m2) - ((m0 + m3) << 1);
F1_noise = (m0 + m3) >> 1;
if ( (F1_sig < MODEAC_MSG_SQUELCH_LEVEL) // minimum required F1 signal amplitude
|| (F1_sig < (F1_noise << 2)) ) // minimum allowable Sig/Noise ratio 4:1
{return (0);}
// If we get here then we have a potential F1, so look for an equally valid F2 20.3uS later
//
// Our F1 is centered somewhere between samples m[1] and m[2]. We can guestimate where F2 is
// by comparing the ratio of m1 and m2, and adding on 20.3 uS (40.6 samples)
//
mPhase = ((m2 * 20) / (m1 + m2));
byte = (mPhase + 812) / 20;
n0 = m[byte++]; n1 = m[byte++];
if (n0 >= n1) // n1 *must* be bigger than n0 for this to be F2
{return (0);}
n2 = m[byte++];
//
// if the sample bob on (Phase == 0), don't look at n3
//
if ((mPhase + 812) % 20)
{n3 = m[byte++];}
else
{n3 = n2; n2 = n0;}
if ( (n3 >= n1) // n1 must be bigger than n3
|| (n0 > n2) // n2 can be equal to n0 ( 0,1,0,0 )
|| (n3 > n2) ) // n2 can be equal to n3 ( 0,1,0,0 )
{return (0);}
F2_sig = (n1 + n2) - ((n0 + n3) << 1);
F2_noise = (n0 + n3) >> 1;
if ( (F2_sig < MODEAC_MSG_SQUELCH_LEVEL) // minimum required F2 signal amplitude
|| (F2_sig < (F2_noise << 2)) ) // maximum allowable Sig/Noise ratio 4:1
{return (0);}
fSig = (F1_sig + F2_sig) >> 1;
fNoise = (F1_noise + F2_noise) >> 1;
fLoLo = fNoise + (fSig >> 2); // 1/2
fLevel = fNoise + (fSig >> 1);
lastBitWasOne = 1;
lastBit = F1_sig;
//
// Now step by a half ModeA bit, 0.725nS, which is 1.45 samples, which is 29/20
// No need to do bit 0 because we've already selected it as a valid F1
// Do several bits past the SPI to increase error rejection
//
for (j = 1, mPhase += 29; j < 48; mPhase += 29, j ++)
{
byte = 1 + (mPhase / 20);
thisSample = m[byte] - fNoise;
if (mPhase % 20) // If the bit is split over two samples...
{thisSample += (m[byte+1] - fNoise);} // add in the second sample's energy
// If we're calculating a space value
if (j & 1)
{lastSpace = thisSample;}
else
{// We're calculating a new bit value
bit = j >> 1;
if (thisSample >= fLevel)
{// We're calculating a new bit value, and its a one
ModeABits |= ModeABitTable[bit--]; // or in the correct bit
if (lastBitWasOne)
{ // This bit is one, last bit was one, so check the last space is somewhere less than one
if ( (lastSpace >= (thisSample>>1)) || (lastSpace >= lastBit) )
{ModeAErrs |= ModeAMidTable[bit];}
}
else
{// This bit,is one, last bit was zero, so check the last space is somewhere less than one
if (lastSpace >= (thisSample >> 1))
{ModeAErrs |= ModeAMidTable[bit];}
}
lastBitWasOne = 1;
}
else
{// We're calculating a new bit value, and its a zero
if (lastBitWasOne)
{ // This bit is zero, last bit was one, so check the last space is somewhere in between
if (lastSpace >= lastBit)
{ModeAErrs |= ModeAMidTable[bit];}
}
else
{// This bit,is zero, last bit was zero, so check the last space is zero too
if (lastSpace >= fLoLo)
{ModeAErrs |= ModeAMidTable[bit];}
}
lastBitWasOne = 0;
}
lastBit = (thisSample >> 1);
}
}
//
// Output format is : 00:A4:A2:A1:00:B4:B2:B1:00:C4:C2:C1:00:D4:D2:D1
//
if ((ModeABits < 3) || (ModeABits & 0xFFFF8808) || (ModeAErrs) )
{return (ModeABits = 0);}
mm->signalLevel = (fSig + fNoise) * (fSig + fNoise) / MAX_POWER;
return ModeABits;
}
//
//=========================================================================
//
// Input format is : 00:A4:A2:A1:00:B4:B2:B1:00:C4:C2:C1:00:D4:D2:D1

2
stats.c
View file

@ -66,8 +66,6 @@ void display_stats(struct stats *st) {
char tb_start[30], tb_end[30];
printf("\n\n");
if (Modes.interactive)
interactiveShowData();
tt_start = st->start/1000;
localtime_r(&tt_start, &tm_start);