1 files changed, 99 insertions, 0 deletions
diff --git a/unittest/t16_8.c b/unittest/t16_8.c
new file mode 100644
index 0000000..1463b30
--- /dev/null
+++ b/unittest/t16_8.c
@@ -0,0 +1,99 @@
+/*
+   t16_8.c
+   David Rowe
+   May 10 2012
+
+   Unit test for 16 <-> 8 kHz sample rate conversion functions.  I
+
+   Evaluated output by plotting using Octave and looking for jaggies:
+
+     pl("../unittest/out16.raw",1,3000)
+     pl("../unittest/out8.raw",1,3000)
+
+   Listening to it also shows up anything nasty:
+
+     $ play -s -2 -r 16000 out16.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 159 /* processing buffer size at 8 kHz (odd number deliberate) */
+#define N16 (N8 * FDMDV_OS)
+#define FRAMES 50
+#define TWO_PI 6.283185307
+#define FS 16000
+
+#define SINE
+
+int main() {
+  float in8k[FDMDV_OS_TAPS_8K + N8];
+  short in8k_short[N8];
+  float out16k[N16];
+  short out16k_short[N16];
+  FILE *f16;
+
+  float in16k[FDMDV_OS_TAPS_16K + N16];
+  float out8k[N16];
+  short out8k_short[N8];
+  FILE *f8, *f8in;
+
+  int i, f, t, t1;
+  float freq = 800.0;
+
+  f16 = fopen("out16.raw", "wb");
+  assert(f16 != NULL);
+  f8 = fopen("out8.raw", "wb");
+  assert(f8 != NULL);
+  f8in = fopen("in8.raw", "wb");
+  assert(f8in != NULL);
+
+  /* clear filter memories */
+  for (i = 0; i < FDMDV_OS_TAPS_8K; i++) in8k[i] = 0.0;
+  for (i = 0; i < FDMDV_OS_TAPS_16K; i++) in16k[i] = 0.0;
+
+  t = t1 = 0;
+  for (f = 0; f < FRAMES; f++) {
+#ifdef DC
+    for (i = 0; i < N8; i++) in8k[FDMDV_OS_TAPS_8K + i] = 16000.0;
+#endif
+#ifdef SINE
+    for (i = 0; i < N8; i++, t++)
+      in8k[FDMDV_OS_TAPS_8K + i] =
+          16000.0 * cos(TWO_PI * t * freq / (FS / FDMDV_OS));
+#endif
+    for (i = 0; i < N8; i++) in8k_short[i] = (short)in8k[i];
+    fwrite(in8k_short, sizeof(short), N8, f8in);
+
+    /* upsample  */
+    fdmdv_8_to_16(out16k, &in8k[FDMDV_OS_TAPS_8K], N8);
+
+    /* save 16k to disk for plotting and check out */
+    for (i = 0; i < N16; i++) out16k_short[i] = (short)out16k[i];
+    fwrite(out16k_short, sizeof(short), N16, f16);
+
+    /* add a 6 kHz spurious signal, down sampler should
+       knock this out */
+    for (i = 0; i < N16; i++, t1++)
+      in16k[i + FDMDV_OS_TAPS_16K] =
+          out16k[i] + 16000.0 * cos(TWO_PI * t1 * 6000.0 / FS);
+
+    /* downsample */
+    fdmdv_16_to_8(out8k, &in16k[FDMDV_OS_TAPS_16K], 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(f16);
+  fclose(f8);
+  fclose(f8in);
+  return 0;
+}