kopia lustrzana https://github.com/cyoung/stratux
Formatting.
Christopher Young
rodzic
229df30ff4
commit
a8e8562e5f
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@ -36,7 +36,8 @@ static void read_from_stdin(void);
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static int process_buffer(uint16_t *phi, int len, uint64_t offset);
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static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors);
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static int demod_uplink_frame(uint16_t *phi, uint8_t *to, int *rs_errors);
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static void demod_frame(uint16_t *phi, uint8_t *frame, int bytes, int16_t center_dphi);
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static void demod_frame(uint16_t *phi, uint8_t *frame, int bytes,
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int16_t center_dphi);
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static void handle_adsb_frame(uint64_t timestamp, uint8_t *frame, int rs);
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static void handle_uplink_frame(uint64_t timestamp, uint8_t *frame, int rs);
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@ -49,8 +50,7 @@ static void handle_uplink_frame(uint64_t timestamp, uint8_t *frame, int rs);
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#ifdef USE_SIGNED_OVERFLOW
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#define phi_difference(from, to) ((int16_t)((to) - (from)))
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#else
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inline int16_t phi_difference(uint16_t from, uint16_t to)
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{
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inline int16_t phi_difference(uint16_t from, uint16_t to) {
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int32_t difference = to - from; // lies in the range -65535 .. +65535
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if (difference >= 32768) // +32768..+65535
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return difference - 65536; // -> -32768..-1: always in range
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@ -62,8 +62,7 @@ inline int16_t phi_difference(uint16_t from, uint16_t to)
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#endif
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#ifndef BUILD_LIB
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int main(int argc, char **argv)
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{
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int main(int argc, char **argv) {
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make_atan2_table();
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init_fec();
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read_from_stdin();
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@ -71,16 +70,15 @@ int main(int argc, char **argv)
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}
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#else
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static CallBack userCB = NULL;
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void Dump978Init(CallBack cb)
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{
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void Dump978Init(CallBack cb) {
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make_atan2_table();
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init_fec();
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userCB = cb;
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}
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#endif
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static void dump_raw_message(char updown, uint8_t *data, int len, int rs_errors)
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{
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static void dump_raw_message(char updown, uint8_t *data, int len,
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int rs_errors) {
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#ifndef BUILD_LIB
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int i;
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@ -97,22 +95,21 @@ static void dump_raw_message(char updown, uint8_t *data, int len, int rs_errors)
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#endif
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}
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static void handle_adsb_frame(uint64_t timestamp, uint8_t *frame, int rs)
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{
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dump_raw_message('-', frame, (frame[0]>>3) == 0 ? SHORT_FRAME_DATA_BYTES : LONG_FRAME_DATA_BYTES, rs);
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static void handle_adsb_frame(uint64_t timestamp, uint8_t *frame, int rs) {
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dump_raw_message('-', frame, (frame[0] >> 3) == 0 ? SHORT_FRAME_DATA_BYTES
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: LONG_FRAME_DATA_BYTES,
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rs);
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fflush(stdout);
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}
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static void handle_uplink_frame(uint64_t timestamp, uint8_t *frame, int rs)
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{
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static void handle_uplink_frame(uint64_t timestamp, uint8_t *frame, int rs) {
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dump_raw_message('+', frame, UPLINK_FRAME_DATA_BYTES, rs);
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fflush(stdout);
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}
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uint16_t iqphase[65536]; // contains value [0..65536) -> [0, 2*pi)
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void make_atan2_table(void)
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{
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void make_atan2_table(void) {
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unsigned i, q;
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union {
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uint8_t iq[2];
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@ -123,18 +120,20 @@ void make_atan2_table(void)
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for (q = 0; q < 256; ++q) {
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double d_i = (i - 127.5);
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double d_q = (q - 127.5);
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double ang = atan2(d_q, d_i) + M_PI; // atan2 returns [-pi..pi], normalize to [0..2*pi]
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double ang = atan2(d_q, d_i) +
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M_PI; // atan2 returns [-pi..pi], normalize to [0..2*pi]
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double scaled_ang = round(32768 * ang / M_PI);
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u.iq[0] = i;
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u.iq[1] = q;
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iqphase[u.iq16] = (scaled_ang < 0 ? 0 : scaled_ang > 65535 ? 65535 : (uint16_t)scaled_ang);
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iqphase[u.iq16] =
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(scaled_ang < 0 ? 0 : scaled_ang > 65535 ? 65535
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: (uint16_t)scaled_ang);
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}
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}
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}
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static void convert_to_phi(uint16_t *buffer, int n)
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{
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static void convert_to_phi(uint16_t *buffer, int n) {
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int i;
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for (i = 0; i < n; ++i)
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@ -142,8 +141,7 @@ static void convert_to_phi(uint16_t *buffer, int n)
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}
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#ifndef BUILD_LIB
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void read_from_stdin(void)
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{
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void read_from_stdin(void) {
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char buffer[65536 * 2];
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int n;
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int used = 0;
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@ -167,8 +165,7 @@ void read_from_stdin(void)
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// #define DEFAULT_SAMPLE_RATE 2048000
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// #define DEFAULT_BUF_LENGTH (262144) 16*16384
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static char buffer[65536 * 2]; // 131072, max received should be 113120
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int process_data(char *data, int dlen)
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{
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int process_data(char *data, int dlen) {
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int n;
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int processed;
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int doffset = 0;
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@ -196,10 +193,8 @@ int process_data(char *data, int dlen)
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}
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#endif
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// Return 1 if word is "equal enough" to expected
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static inline int sync_word_fuzzy_compare(uint64_t word, uint64_t expected)
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{
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static inline int sync_word_fuzzy_compare(uint64_t word, uint64_t expected) {
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uint64_t diff;
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if (word == expected)
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@ -262,8 +257,7 @@ static inline int sync_word_fuzzy_compare(uint64_t word, uint64_t expected)
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// that matches the sync word 'pattern'. Place the dphi
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// threshold to use for bit slicing in '*center'. Return 1
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// if the sync word is OK, 0 on failure
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int check_sync_word(uint16_t *phi, uint64_t pattern, int16_t *center)
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{
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int check_sync_word(uint16_t *phi, uint64_t pattern, int16_t *center) {
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int i;
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int32_t dphi_zero_total = 0;
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int zero_bits = 0;
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@ -305,15 +299,15 @@ int check_sync_word(uint16_t *phi, uint64_t pattern, int16_t *center)
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}
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}
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//fprintf(stdout, "check_sync_word: center=%.0fkHz, errors=%d\n", *center * 2083334.0 / 65536 / 1000, error_bits);
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// fprintf(stdout, "check_sync_word: center=%.0fkHz, errors=%d\n", *center *
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// 2083334.0 / 65536 / 1000, error_bits);
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return (error_bits <= MAX_SYNC_ERRORS);
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}
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#define SYNC_MASK ((((uint64_t)1) << SYNC_BITS) - 1)
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int process_buffer(uint16_t *phi, int len, uint64_t offset)
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{
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int process_buffer(uint16_t *phi, int len, uint64_t offset) {
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uint64_t sync0 = 0, sync1 = 0;
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int lenbits;
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int bit;
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@ -360,7 +354,8 @@ int process_buffer(uint16_t *phi, int len, uint64_t offset)
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// errors.
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// check for downlink frames:
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if (sync_word_fuzzy_compare(sync0, ADSB_SYNC_WORD) || sync_word_fuzzy_compare(sync1, ADSB_SYNC_WORD)) {
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if (sync_word_fuzzy_compare(sync0, ADSB_SYNC_WORD) ||
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sync_word_fuzzy_compare(sync1, ADSB_SYNC_WORD)) {
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int startbit = (bit - SYNC_BITS + 1);
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int shift = (sync_word_fuzzy_compare(sync0, ADSB_SYNC_WORD) ? 0 : 1);
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int index = startbit * 2 + shift;
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@ -384,7 +379,8 @@ int process_buffer(uint16_t *phi, int len, uint64_t offset)
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}
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// check for uplink frames:
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else if (sync_word_fuzzy_compare(sync0, UPLINK_SYNC_WORD) || sync_word_fuzzy_compare(sync1, UPLINK_SYNC_WORD)) {
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else if (sync_word_fuzzy_compare(sync0, UPLINK_SYNC_WORD) ||
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sync_word_fuzzy_compare(sync1, UPLINK_SYNC_WORD)) {
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int startbit = (bit - SYNC_BITS + 1);
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int shift = (sync_word_fuzzy_compare(sync0, UPLINK_SYNC_WORD) ? 0 : 1);
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int index = startbit * 2 + shift;
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@ -413,18 +409,26 @@ int process_buffer(uint16_t *phi, int len, uint64_t offset)
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// demodulate 'bytes' bytes from samples at 'phi' into 'frame',
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// using 'center_dphi' as the bit slicing threshold
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static void demod_frame(uint16_t *phi, uint8_t *frame, int bytes, int16_t center_dphi)
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{
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static void demod_frame(uint16_t *phi, uint8_t *frame, int bytes,
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int16_t center_dphi) {
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while (--bytes >= 0) {
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uint8_t b = 0;
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if (phi_difference(phi[0], phi[1]) > center_dphi) b |= 0x80;
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if (phi_difference(phi[2], phi[3]) > center_dphi) b |= 0x40;
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if (phi_difference(phi[4], phi[5]) > center_dphi) b |= 0x20;
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if (phi_difference(phi[6], phi[7]) > center_dphi) b |= 0x10;
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if (phi_difference(phi[8], phi[9]) > center_dphi) b |= 0x08;
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if (phi_difference(phi[10], phi[11]) > center_dphi) b |= 0x04;
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if (phi_difference(phi[12], phi[13]) > center_dphi) b |= 0x02;
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if (phi_difference(phi[14], phi[15]) > center_dphi) b |= 0x01;
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if (phi_difference(phi[0], phi[1]) > center_dphi)
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b |= 0x80;
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if (phi_difference(phi[2], phi[3]) > center_dphi)
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b |= 0x40;
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if (phi_difference(phi[4], phi[5]) > center_dphi)
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b |= 0x20;
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if (phi_difference(phi[6], phi[7]) > center_dphi)
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b |= 0x10;
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if (phi_difference(phi[8], phi[9]) > center_dphi)
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b |= 0x08;
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if (phi_difference(phi[10], phi[11]) > center_dphi)
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b |= 0x04;
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if (phi_difference(phi[12], phi[13]) > center_dphi)
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b |= 0x02;
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if (phi_difference(phi[14], phi[15]) > center_dphi)
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b |= 0x01;
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*frame++ = b;
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phi += 16;
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}
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@ -436,8 +440,7 @@ static void demod_frame(uint16_t *phi, uint8_t *frame, int bytes, int16_t center
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// number of corrected errors, or 9999 if demodulation failed.
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// Return 0 if demodulation failed, or the number of bits (not
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// samples) consumed if demodulation was OK.
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static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors)
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{
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static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors) {
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int16_t center_dphi;
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int frametype;
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@ -462,8 +465,7 @@ static int demod_adsb_frame(uint16_t *phi, uint8_t *to, int *rs_errors)
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// number of corrected errors, or 9999 if demodulation failed.
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// Return 0 if demodulation failed, or the number of bits (not
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// samples) consumed if demodulation was OK.
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static int demod_uplink_frame(uint16_t *phi, uint8_t *to, int *rs_errors)
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{
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static int demod_uplink_frame(uint16_t *phi, uint8_t *to, int *rs_errors) {
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int16_t center_dphi;
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uint8_t interleaved[UPLINK_FRAME_BYTES];
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@ -472,7 +474,8 @@ static int demod_uplink_frame(uint16_t *phi, uint8_t *to, int *rs_errors)
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return 0;
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}
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demod_frame(phi + SYNC_BITS*2, interleaved, UPLINK_FRAME_BYTES, center_dphi);
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demod_frame(phi + SYNC_BITS * 2, interleaved, UPLINK_FRAME_BYTES,
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center_dphi);
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// deinterleave and correct
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if (correct_uplink_frame(interleaved, to, rs_errors) == 1)
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