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Rearrangements to the receive thread.

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Magnitude conversion now happens immediately when sample data is
received, so there is no risk of newly received data clobbering old
data under CPU overload.
This commit is contained in:
Oliver Jowett 2015-04-09 18:51:31 +01:00
parent e6c81251bf
commit 15ea5ba3da
11 changed files with 234 additions and 160 deletions
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11
demod_2400.c
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@ -155,7 +155,7 @@ static int best_phase(uint16_t *m) {
// Given 'mlen' magnitude samples in 'm', sampled at 2.4MHz,
// try to demodulate some Mode S messages.
//
void demodulate2400(uint16_t *m, uint32_t mlen) {
void demodulate2400(struct mag_buf *mag) {
struct modesMessage mm;
unsigned char msg1[MODES_LONG_MSG_BYTES], msg2[MODES_LONG_MSG_BYTES], *msg;
uint32_t j;
@ -172,6 +172,9 @@ void demodulate2400(uint16_t *m, uint32_t mlen) {
uint64_t noise_power_sum = 0;
#endif
uint16_t *m = mag->data;
uint32_t mlen = mag->length;
memset(&mm, 0, sizeof(mm));
msg = msg1;
@ -424,11 +427,11 @@ void demodulate2400(uint16_t *m, uint32_t mlen) {
msglen = modesMessageLenByType(bestmsg[0] >> 3);
// Set initial mm structure details
mm.timestampMsg = Modes.timestampBlk + (j*5) + bestphase;
mm.timestampMsg = mag->sampleTimestamp + (j*5) + bestphase;
// compute message receive time as block-start-time + difference in the 12MHz clock
mm.sysTimestampMsg = Modes.stSystemTimeBlk; // end of block time
mm.sysTimestampMsg.tv_nsec -= receiveclock_ns_elapsed(mm.timestampMsg, Modes.timestampBlk + MODES_ASYNC_BUF_SAMPLES * 5); // time until end of block
mm.sysTimestampMsg = mag->sysTimestamp; // start of block time
mm.sysTimestampMsg.tv_nsec += receiveclock_ns_elapsed(mag->sampleTimestamp, mm.timestampMsg);
normalize_timespec(&mm.sysTimestampMsg);
mm.score = bestscore;