add powers command

powers.c

@@ -0,0 +1,241 @@
+// $Id$
+// read FFT bin energies from spectrum pseudo-demod and format similar to rtl_power
+// Copyright 2023 Phil Karn, KA9Q
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <locale.h>
+#include <assert.h>
+#include "misc.h"
+#include "status.h"
+#include "multicast.h"
+#include "radio.h"
+
+
+struct sockaddr_storage Metadata_dest_address;      // Dest of metadata (typically multicast)
+struct sockaddr_storage Metadata_source_address;      // Source of metadata
+int IP_tos;
+int Mcast_ttl = 1;
+
+
+
+const char *App_path;
+int Verbose;
+uint32_t Ssrc;
+char Locale[256] = "en_US.UTF-8";
+char Iface[1024]; // Multicast interface to talk to front end
+int Status_fd,Ctl_fd;
+
+int dump_powers(float *power,int npower,uint64_t *time,double *freq,double *bin_bw,int32_t const ssrc,uint8_t const * const buffer,int length);
+
+int main(int argc,char *argv[]){
+  App_path = argv[0];
+  {
+    int c;
+    while((c = getopt(argc,argv,"vs:")) != -1){
+      switch(c){
+      case 'v':
+	Verbose++;
+	break;
+      case 's':
+	Ssrc = strtol(optarg,NULL,0); // Send to specific SSRC
+	break;
+      default:
+	fprintf(stdout,"Unknown option %c\n",c);
+	break;
+      }
+    }
+  }
+  {
+    // The display thread assumes en_US.UTF-8, or anything with a thousands grouping character
+    // Otherwise the cursor movements will be wrong
+    char const * const cp = getenv("LANG");
+    if(cp != NULL){
+      strlcpy(Locale,cp,sizeof(Locale));
+    }
+  }
+  setlocale(LC_ALL,Locale); // Set either the hardwired default or the value of $LANG if it exists
+  // Dummy filter
+
+  resolve_mcast(argv[optind],&Metadata_dest_address,DEFAULT_STAT_PORT,Iface,sizeof(Iface));
+  Status_fd = listen_mcast(&Metadata_dest_address,Iface);
+  if(Status_fd == -1){
+    fprintf(stderr,"Can't listen to mcast status %s\n",argv[optind]);
+    exit(1);
+  }
+  Ctl_fd = connect_mcast(&Metadata_dest_address,Iface,Mcast_ttl,IP_tos);
+  if(Ctl_fd < 0){
+    fprintf(stderr,"connect to mcast control failed\n");
+    exit(1);
+  }
+
+  // The deadline starts at 1 sec in the future
+  // It is reset as long as we keep seeing our responses
+  int64_t deadline = gps_time_ns() + BILLION;
+
+  // Send command to set up the channel?? Or do in a separate command? We'd like to reuse the same demod & ssrc,
+  // which is hard to do in one command, as we'd have to stash the ssrc somewhere.
+  for(;;){
+    // Send poll
+    usleep(1000000);
+
+    {
+      int64_t timeout = deadline - gps_time_ns();
+      // Immediate poll if timeout is negative
+      if(timeout < 0)
+	timeout = 0;
+
+      send_poll(Ctl_fd,0);
+      fd_set fdset;
+      FD_ZERO(&fdset);
+      FD_SET(Status_fd,&fdset);
+      int n = Status_fd + 1;
+      {
+	struct timespec ts;
+	ns2ts(&ts,timeout);
+	n = pselect(n,&fdset,NULL,NULL,&ts,NULL);
+      }
+      if(n <= 0)
+	continue; // Only on a timeout
+      if(!FD_ISSET(Status_fd,&fdset))
+	continue;
+    }      
+    // Message from the radio program
+    uint8_t buffer[8192];
+    socklen_t ssize = sizeof(Metadata_source_address);
+    int const length = recvfrom(Status_fd,buffer,sizeof(buffer),0,(struct sockaddr *)&Metadata_source_address,&ssize);
+
+    // Ignore our own command packets
+    if(length < 2 || buffer[0] != 0)
+      continue;
+    int const ssrc = get_ssrc(buffer+1,length-1);
+    if(ssrc != Ssrc)
+      continue; // Not the droid we're looking for
+    deadline = gps_time_ns() + BILLION; // extend deadline as long as we're progressing
+
+    float powers[65536];
+    uint64_t time;
+    double freq;
+    double bin_bw;
+
+    int npower = dump_powers(powers,sizeof(powers) / sizeof (powers[0]), &time,&freq,&bin_bw,ssrc,buffer+1,length-1);
+    if(npower < 0)
+      continue; // Invalid for some reason
+    // Note from VK5QI:
+    // the output format from that utility matches that produced by rtl_power, which is: 
+    //2022-04-02, 16:24:55, 400050181, 401524819, 450.13, 296, -52.95, -53.27, -53.26, -53.24, -53.40, <many more points here>
+    // date, time, start_frequency, stop_frequency, bin_size_hz, number_bins, data0, data1, data2
+
+    // **************Process here ***************
+    char gps[1024];
+    printf("%s,",format_gpstime(gps,sizeof(gps),time));
+
+    if(npower & 1){
+      // Odd: emit N/2+1....N-1 0....N/2 (division truncating to integer)
+      double f = freq - bin_bw * npower / 2;
+      printf(" %.0f, %.0f, %.0f, %d",
+	     f - bin_bw * npower/2, f + bin_bw * npower/2, bin_bw, npower);
+
+      for(int i= npower/2; i < npower; i++)
+	printf(" ,%.1f",powers[i] == 0 ? -100.0 : 10*log10(powers[i]));
+      for(int i= 0; i < npower/2; i++)
+	printf(" ,%.1f",powers[i] == 0 ? -100.0 : 10*log10(powers[i]));
+    } else {
+      // Even: emit N/2....N-1 0....N/2-1
+      double f = freq - bin_bw * npower / 2;
+      printf(" %.0f, %.0f, %.0f, %d",
+	     f - bin_bw * npower/2, f + bin_bw * npower/2, bin_bw, npower);
+
+      for(int i= npower/2; i < npower; i++)
+	printf(" ,%.1f",powers[i] == 0 ? -100.0 : 10*log10(powers[i]));
+      for(int i= 0; i < npower/2; i++)
+	printf(" ,%.1f",powers[i] == 0 ? -100.0 : 10*log10(powers[i]));
+    }
+    printf("\n");
+  }
+}
+
+// Decode only those status fields relevant to spectrum measurement
+int dump_powers(float *power,int npower,uint64_t *time,double *freq,double *bin_bw,int32_t const ssrc,uint8_t const * const buffer,int length){
+#if 0  // use later
+  double l_lo1 = 0,l_lo2 = 0;
+#endif
+  int l_ccount = 0;
+  uint8_t const *cp = buffer;
+  int l_count;
+
+  while(cp - buffer < length){
+    enum status_type const type = *cp++; // increment cp to length field
+
+    if(type == EOL)
+      break; // End of list
+
+    unsigned int optlen = *cp++;
+    if(optlen & 0x80){
+      // length is >= 128 bytes; fetch actual length from next N bytes, where N is low 7 bits of optlen
+      int length_of_length = optlen & 0x7f;
+      optlen = 0;
+      while(length_of_length > 0){
+	optlen <<= 8;
+	optlen |= *cp++;
+	length_of_length--;
+      }
+    }
+    if(cp - buffer + optlen >= length)
+      break; // Invalid length
+    switch(type){
+    case EOL: // Shouldn't get here
+      goto done;
+    case GPS_TIME:
+      *time = (uint64_t)decode_int(cp,optlen);
+      break;
+    case OUTPUT_SSRC: // Don't really need this, it's already been checked
+      if(decode_int(cp,optlen) != ssrc)
+	return -1; // Not what we want
+      break;
+    case DEMOD_TYPE:
+      {
+	const int i = (int)decode_int(cp,optlen);
+	if(i != SPECT_DEMOD)
+	  return -1; // Not what we want
+      }
+      break;
+    case RADIO_FREQUENCY:
+      *freq = decode_double(cp,optlen);
+      break;
+#if 0  // Use this to fine-tweak freq later
+    case FIRST_LO_FREQUENCY:
+      l_lo1 = decode_double(cp,optlen);
+      break;
+    case SECOND_LO_FREQUENCY: // ditto
+      l_lo2 = decode_double(cp,optlen);
+      break;
+#endif
+    case BIN_DATA:
+      l_count = optlen/sizeof(float);
+      if(l_count > npower)
+	return -2; // Not enough room in caller's array
+      // Note these are still in FFT order
+      for(int i=0; i < l_count; i++){
+	power[i] = decode_float(cp,sizeof(float));
+	cp += sizeof(float);
+      }
+      break;
+    case NONCOHERENT_BIN_BW:
+      *bin_bw = decode_float(cp,optlen);
+      break;
+    case BIN_COUNT: // Do we check that this equals the length of the BIN_DATA tlv?
+      l_ccount = decode_int(cp,optlen);
+      break;
+    default:
+      break;
+    }
+    cp += optlen;
+  }
+ done:
+  ;
+  assert(l_ccount == l_count);
+  return l_ccount;
+}