/* Test viterbi decoder speeds */
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <math.h>
#include <memory.h>
#include <sys/time.h>
#include <sys/resource.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include "fec.h"

#if HAVE_GETOPT_LONG
struct option Options[] = {
  {"frame-length", 1, NULL, 'l'},
  {"frame-count", 1, NULL, 'n'},
  {"ebn0", 1, NULL, 'e'},
  {"gain", 1, NULL, 'g'},
  {"verbose", 0, NULL, 'v'},
  {"force-altivec", 0, NULL, 'a'},
  {"force-port", 0, NULL, 'p'},
  {"force-mmx", 0, NULL, 'm'},
  {"force-sse", 0, NULL, 's'},
  {"force-sse2", 0, NULL, 't'},
  {NULL},
};
#endif

#define RATE (1./2.)
#define MAXBYTES 10000

double Gain = 32.0;
int Verbose = 0;

int main(int argc, char *argv[])
{
  int i, d, tr;
  int sr = 0, trials = 10000, errcnt, framebits = 2048;
  long long int tot_errs = 0;
  unsigned char bits[MAXBYTES];
  unsigned char data[MAXBYTES];
  unsigned char xordata[MAXBYTES];
  unsigned char symbols[8 * 2 * (MAXBYTES + 6)];
  void *vp;
  extern char *optarg;
  struct rusage start, finish;
  double extime;
  double gain, esn0, ebn0;
  time_t t;
  int badframes = 0;

  time(&t);
  srandom(t);
  ebn0 = -100;
#if HAVE_GETOPT_LONG
  while ((d = getopt_long(argc, argv, "l:n:te:g:vapmst", Options, NULL)) != EOF) {
#else
  while ((d = getopt(argc, argv, "l:n:te:g:vapmst")) != EOF) {
#endif
    switch (d) {
    case 'a':
      Cpu_mode = ALTIVEC;
      break;
    case 'p':
      Cpu_mode = PORT;
      break;
    case 'm':
      Cpu_mode = MMX;
      break;
    case 's':
      Cpu_mode = SSE;
      break;
    case 't':
      Cpu_mode = SSE2;
      break;
    case 'l':
      framebits = atoi(optarg);
      break;
    case 'n':
      trials = atoi(optarg);
      break;
    case 'e':
      ebn0 = atof(optarg);
      break;
    case 'g':
      Gain = atof(optarg);
      break;
    case 'v':
      Verbose++;
      break;
    }
  }
  if (framebits > 8 * MAXBYTES) {
    fprintf(stderr, "Frame limited to %d bits\n", MAXBYTES * 8);
    framebits = MAXBYTES * 8;
  }
  if ((vp = create_viterbi27(framebits)) == NULL) {
    printf("create_viterbi27 failed\n");
    exit(1);
  }
  if (ebn0 != -100) {
    esn0 = ebn0 + 10 * log10((double)RATE); /* Es/No in dB */
    /* Compute noise voltage. The 0.5 factor accounts for BPSK seeing
     * only half the noise power, and the sqrt() converts power to
     * voltage.
     */
    gain = 1. / sqrt(0.5 / pow(10., esn0 / 10.));

    printf("nframes = %d framesize = %d ebn0 = %.2f dB gain = %g\n", trials,
           framebits, ebn0, Gain);

    for (tr = 0; tr < trials; tr++) {
      /* Encode a frame of random data */
      for (i = 0; i < framebits + 6; i++) {
        int bit = (i < framebits) ? (random() & 1) : 0;

        sr = (sr << 1) | bit;
        bits[i / 8] = sr & 0xff;
        symbols[2 * i + 0] = addnoise(parity(sr & V27POLYA), gain, Gain, 127.5, 255);
        symbols[2 * i + 1] = addnoise(parity(sr & V27POLYB), gain, Gain, 127.5, 255);
      }
      /* Decode it and make sure we get the right answer */
      /* Initialize Viterbi decoder */
      init_viterbi27(vp, 0);

      /* Decode block */
      update_viterbi27_blk(vp, symbols, framebits + 6);

      /* Do Viterbi chainback */
      chainback_viterbi27(vp, data, framebits, 0);
      errcnt = 0;
      for (i = 0; i < framebits / 8; i++) {
        int e = Bitcnt[xordata[i] = data[i] ^ bits[i]];
        errcnt += e;
        tot_errs += e;
      }
      if (errcnt != 0) {
        badframes++;
      }
      if (Verbose > 1 && errcnt != 0) {
        printf("frame %d, %d errors: ", tr, errcnt);
        for (i = 0; i < framebits / 8; i++) {
          printf("%02x", xordata[i]);
        }
        printf("\n");
      }
      if (Verbose)
        printf("BER %lld/%lld (%10.3g) FER %d/%d (%10.3g)\r",
               tot_errs, (long long)framebits * (tr + 1),
               tot_errs / ((double)framebits * (tr + 1)),
               badframes, tr + 1, (double)badframes / (tr + 1));
      fflush(stdout);
    }
    if (Verbose > 1) {
      printf("nframes = %d framesize = %d ebn0 = %.2f dB gain = %g\n", trials,
             framebits, ebn0, Gain);
    }
    else if (Verbose == 0)
      printf("BER %lld/%lld (%.3g) FER %d/%d (%.3g)\n",
             tot_errs, (long long)framebits * trials,
             tot_errs / ((double)framebits * trials),
             badframes, tr + 1, (double)badframes / (tr + 1));
    else {
      printf("\n");
    }

  }
  else {
    /* Do time trials */
    memset(symbols, 127, sizeof(symbols));
    printf("Starting time trials\n");
    getrusage(RUSAGE_SELF, &start);
    for (tr = 0; tr < trials; tr++) {
      /* Initialize Viterbi decoder */
      init_viterbi27(vp, 0);

      /* Decode block */
      update_viterbi27_blk(vp, symbols, framebits);

      /* Do Viterbi chainback */
      chainback_viterbi27(vp, data, framebits, 0);
    }
    getrusage(RUSAGE_SELF, &finish);
    extime = finish.ru_utime.tv_sec - start.ru_utime.tv_sec + 1e-6 *
             (finish.ru_utime.tv_usec - start.ru_utime.tv_usec);
    printf("Execution time for %d %d-bit frames: %.2f sec\n", trials,
           framebits, extime);
    printf("decoder speed: %g bits/s\n", trials * framebits / extime);
  }
  exit(0);
}