/*
   t48_8.c
   David Rowe
   May 10 2012

   Unit test for 48 to 8 kHz sample rate conversion functions.  I
   evaluated output by plotting using Octave and looking for jaggies:

     pl("../unittest/out48.raw",1,3000)
     pl("../unittest/out8.raw",1,3000)

   Listening to it also shows up anything nasty:

     $ play -s -2 -r 48000 out48.raw
     $ play -s -2 -r 8000 out8.raw

  */

#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#include "codec2_fdmdv.h"

#define N8 180 /* processing buffer size at 8 kHz */
#define N48 (N8 * FDMDV_OS_48)
#define MEM8 FDMDV_OS_TAPS_48_8K
#define FRAMES 50
#define TWO_PI 6.283185307
#define FS 48000

#define SINE

int main() {
  float in8k[MEM8 + N8];
  short in8k_short[N8];
  float out48k[N48];
  short out48k_short[N48];
  FILE *f48;

  float in48k[FDMDV_OS_TAPS_48K + N48];
  float out8k[N48];
  short out8k_short[N8];
  FILE *f8, *f8in;

  int i, f, t, t1;
  float freq = 800.0;

  f48 = fopen("out48.raw", "wb");
  assert(f48 != NULL);
  f8 = fopen("out8.raw", "wb");
  assert(f8 != NULL);
  f8in = fopen("in8.raw", "wb");
  assert(f8in != NULL);

  /* clear filter memories */

  for (i = 0; i < MEM8; i++) in8k[i] = 0.0;
  for (i = 0; i < FDMDV_OS_TAPS_48K; i++) in48k[i] = 0.0;

  t = t1 = 0;
  for (f = 0; f < FRAMES; f++) {
#ifdef DC
    for (i = 0; i < N8; i++) in8k[MEM8 + i] = 16000.0;
#endif
#ifdef SINE
    for (i = 0; i < N8; i++, t++)
      in8k[MEM8 + i] = 16000.0 * cos(TWO_PI * t * freq / (FS / FDMDV_OS_48));
#endif
    for (i = 0; i < N8; i++) in8k_short[i] = (short)in8k[i];
    fwrite(in8k_short, sizeof(short), N8, f8in);

    /* upsample  */

    fdmdv_8_to_48(out48k, &in8k[MEM8], N8);

    /* save 48k to disk for plotting and check out */

    for (i = 0; i < N48; i++) out48k_short[i] = (short)out48k[i];
    fwrite(out48k_short, sizeof(short), N48, f48);

    /* add a 10 kHz spurious signal for fun, we want down sampler to
       knock this out */

    for (i = 0; i < N48; i++, t1++)
      in48k[i + FDMDV_OS_TAPS_48K] =
          out48k[i] + 16000.0 * cos(TWO_PI * t1 * 1E4 / FS);

    /* downsample */

    fdmdv_48_to_8(out8k, &in48k[FDMDV_OS_TAPS_48K], N8);

    /* save 8k to disk for plotting and check out */

    for (i = 0; i < N8; i++) out8k_short[i] = (short)out8k[i];
    fwrite(out8k_short, sizeof(short), N8, f8);
  }

  fclose(f48);
  fclose(f8);
  fclose(f8in);
  return 0;
}
