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initial lib hackery

pull/13/head^2
Joseph Poirier 2015-08-14 09:10:04 -05:00
rodzic 8f4312311d
commit 049fcac8a2
1 zmienionych plików z 72 dodań i 18 usunięć
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90
dump978/dump978.c
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@ -2,17 +2,17 @@
// Copyright 2015, Oliver Jowett <oliver@mutability.co.uk>
//
// This file is free software: you may copy, redistribute and/or modify it
// This file is free software: you may copy, redistribute and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation, either version 2 of the License, or (at your
// option) any later version.
// Free Software Foundation, either version 2 of the License, or (at your
// option) any later version.
//
// This file is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// This file is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#include <stdio.h>
@ -25,8 +25,14 @@
#include "uat.h"
#include "fec.h"
static void make_atan2_table();
static void read_from_stdin();
#ifdef LIB_CREATE
#include "dump978.h"
#endif
static void make_atan2_table(void);
#ifndef LIB_CREATE
static void read_from_stdin(void);
#endif
static int process_buffer(uint16_t *phi, int len, uint64_t offset);
static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors);
static int demod_uplink_frame(uint16_t *phi, uint8_t *to, int *rs_errors);
@ -55,6 +61,7 @@ inline int16_t phi_difference(uint16_t from, uint16_t to)
}
#endif
#ifndef LIB_CREATE
int main(int argc, char **argv)
{
make_atan2_table();
@ -62,9 +69,20 @@ int main(int argc, char **argv)
read_from_stdin();
return 0;
}
#else
typedef void (*CallBack)(char updown, uint8_t *data, int len);
static CallBack userCB = NULL;
void init(CallBack cb)
{
make_atan2_table();
init_fec();
userCB = cb;
}
#endif
static void dump_raw_message(char updown, uint8_t *data, int len, int rs_errors)
{
#ifndef LIB_CREATE
int i;
fprintf(stdout, "%c", updown);
@ -75,6 +93,9 @@ static void dump_raw_message(char updown, uint8_t *data, int len, int rs_errors)
if (rs_errors)
fprintf(stdout, ";rs=%d", rs_errors);
fprintf(stdout, ";\n");
#else
userCB(updown, data, len);
#endif
}
static void handle_adsb_frame(uint64_t timestamp, uint8_t *frame, int rs)
@ -91,7 +112,7 @@ static void handle_uplink_frame(uint64_t timestamp, uint8_t *frame, int rs)
uint16_t iqphase[65536]; // contains value [0..65536) -> [0, 2*pi)
void make_atan2_table()
void make_atan2_table(void)
{
unsigned i,q;
union {
@ -121,13 +142,14 @@ static void convert_to_phi(uint16_t *buffer, int n)
buffer[i] = iqphase[buffer[i]];
}
void read_from_stdin()
#ifndef LIB_CREATE
void read_from_stdin(void)
{
char buffer[65536*2];
int n;
int used = 0;
uint64_t offset = 0;
while ( (n = read(0, buffer+used, sizeof(buffer)-used)) > 0 ) {
int processed;
@ -142,6 +164,38 @@ void read_from_stdin()
}
}
}
#else
// #define DEFAULT_SAMPLE_RATE 2048000
// #define DEFAULT_BUF_LENGTH (262144) 16*16384
static char buffer[65536*2]; // 131072, max received should be 113120
int process_data(char *data, int dlen)
{
int n;
int processed;
int doffset = 0;
static int used = 0;
static uint64_t offset = 0;
while (dlen > 0) {
n = (sizeof(buffer)-used) >= dlen ? dlen : (sizeof(buffer)-used);
memcpy(buffer+used, data+doffset, n);
convert_to_phi((uint16_t*) (buffer+(used&~1)), ((used&1)+n)/2);
used += n;
processed = process_buffer((uint16_t*)buffer, used/2, offset);
used -= processed * 2;
offset += processed;
if (used > 0) {
memmove(buffer, buffer+processed*2, used);
}
doffset += n;
dlen -= n;
}
return dlen;
}
#endif
// Return 1 if word is "equal enough" to expected
@ -166,19 +220,19 @@ static inline int sync_word_fuzzy_compare(uint64_t word, uint64_t expected)
//
// 010101010101010000
// ^
// Subtracting one, will flip the
// Subtracting one, will flip the
// bits starting at the last set bit:
//
// 010101010101001111
// ^
// then we can use that as a bitwise-and
// then we can use that as a bitwise-and
// mask to clear the lowest set bit:
//
// 010101010101000000
// ^
// And repeat until the value is zero
// or we have seen too many set bits.
// >= 1 bit
diff &= (diff-1); // clear lowest set bit
if (!diff)
@ -259,7 +313,7 @@ int check_sync_word(uint16_t *phi, uint64_t pattern, int16_t *center)
#define SYNC_MASK ((((uint64_t)1)<<SYNC_BITS)-1)
int process_buffer(uint16_t *phi, int len, uint64_t offset)
int process_buffer(uint16_t *phi, int len, uint64_t offset)
{
uint64_t sync0 = 0, sync1 = 0;
int lenbits;
@ -298,7 +352,7 @@ int process_buffer(uint16_t *phi, int len, uint64_t offset)
continue; // haven't fully populated sync0/1 yet
// see if we have (the start of) a valid sync word
// It would be nice to look at popcount(expected ^ sync)
// It would be nice to look at popcount(expected ^ sync)
// so we can tolerate some errors, but that turns out
// to be very expensive to do on every sample
@ -393,7 +447,7 @@ static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors)
return 0;
}
demod_frame(phi + SYNC_BITS*2, to, LONG_FRAME_BYTES, center_dphi);
demod_frame(phi + SYNC_BITS*2, to, LONG_FRAME_BYTES, center_dphi);
frametype = correct_adsb_frame(to, rs_errors);
if (frametype == 1)
return (SYNC_BITS + SHORT_FRAME_BITS);