--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/tests/r2_mf_rx_tests.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,538 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * r2_mf_tests.c - Test the R2 MF detector against the spec., whatever the
+ *                 spec. may be :)
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: r2_mf_rx_tests.c,v 1.4 2006/11/19 14:07:27 steveu Exp $
+ */
+
+/*! \file */
+
+/*! \page r2_mf_tests_page R2 MF tone generation and detection tests
+\section r2_mf_tests_page_sec_1 What does it do?
+These tests are fashioned after those on the CM7291 test tape from
+Mitel. Those tests are for DTMF, rather than R2 MF, but make a
+fair starting point for a set of meaningful tests of R2 MF.
+
+These tests include conversion to and from A-law. It is assumed the
+distortion this produces is comparable to u-law, so it should be
+a fair test of performance in a real PSTN channel.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+#include <stdio.h>
+#include <time.h>
+#include <fcntl.h>
+#include <audiofile.h>
+#include <tiffio.h>
+
+#include "spandsp.h"
+
+/* R2 tone generation specs.
+ *  Power: -11.5dBm +- 1dB
+ *  Frequency: within +-4Hz
+ *  Mismatch between the start time of a pair of tones: <=1ms.
+ *  Mismatch between the end time of a pair of tones: <=1ms.
+ */
+/* Basic MFC/R2 tone detection specs:
+ *  Receiver response range: -5dBm to -35dBm
+ *  Difference in level for a pair of frequencies
+ *      Adjacent tones: <5dB
+ *      Non-adjacent tones: <7dB
+ *  Receiver not to detect a signal of 2 frequencies of level -5dB and
+ *  duration <7ms.
+ *  Receiver not to recognise a signal of 2 frequencies having a difference
+ *  in level >=20dB.
+ *  Max received signal frequency error: +-10Hz
+ *  The sum of the operate and release times of a 2 frequency signal not to
+ *  exceed 80ms (there are no individual specs for the operate and release
+ *  times).
+ *  Receiver not to release for signal interruptions <=7ms.
+ *  System malfunction due to signal interruptions >7ms (typically 20ms) is
+ *  prevented by further logic elements.
+ */
+
+#define MF_DURATION                 (68*8)
+#define MF_PAUSE                    (68*8)
+#define MF_CYCLE                    (MF_DURATION + MF_PAUSE)
+
+typedef struct
+{
+    float       f1;         /* First freq */
+    float       f2;         /* Second freq */
+    int8_t      level1;     /* Level of the first freq (dB) */
+    int8_t      level2;     /* Level of the second freq (dB) */
+    uint8_t     on_time;    /* Tone on time (ms) */
+    uint8_t     off_time;   /* Minimum post tone silence (ms) */
+} mf_digit_tones_t;
+
+static const mf_digit_tones_t r2_mf_fwd_tones[] =
+{
+    {1380.0, 1500.0, -11, -11, 1, 0},
+    {1380.0, 1620.0, -11, -11, 1, 0},
+    {1500.0, 1620.0, -11, -11, 1, 0},
+    {1380.0, 1740.0, -11, -11, 1, 0},
+    {1500.0, 1740.0, -11, -11, 1, 0},
+    {1620.0, 1740.0, -11, -11, 1, 0},
+    {1380.0, 1860.0, -11, -11, 1, 0},
+    {1500.0, 1860.0, -11, -11, 1, 0},
+    {1620.0, 1860.0, -11, -11, 1, 0},
+    {1740.0, 1860.0, -11, -11, 1, 0},
+    {1380.0, 1980.0, -11, -11, 1, 0},
+    {1500.0, 1980.0, -11, -11, 1, 0},
+    {1620.0, 1980.0, -11, -11, 1, 0},
+    {1740.0, 1980.0, -11, -11, 1, 0},
+    {1860.0, 1980.0, -11, -11, 1, 0},
+    {0.0, 0.0, 0, 0, 0, 0}
+};
+
+static const mf_digit_tones_t r2_mf_back_tones[] =
+{
+    {1140.0, 1020.0, -11, -11, 1, 0},
+    {1140.0,  900.0, -11, -11, 1, 0},
+    {1020.0,  900.0, -11, -11, 1, 0},
+    {1140.0,  780.0, -11, -11, 1, 0},
+    {1020.0,  780.0, -11, -11, 1, 0},
+    { 900.0,  780.0, -11, -11, 1, 0},
+    {1140.0,  660.0, -11, -11, 1, 0},
+    {1020.0,  660.0, -11, -11, 1, 0},
+    { 900.0,  660.0, -11, -11, 1, 0},
+    { 780.0,  660.0, -11, -11, 1, 0},
+    {1140.0,  540.0, -11, -11, 1, 0},
+    {1020.0,  540.0, -11, -11, 1, 0},
+    { 900.0,  540.0, -11, -11, 1, 0},
+    { 780.0,  540.0, -11, -11, 1, 0},
+    { 660.0,  540.0, -11, -11, 1, 0},
+    {0.0, 0.0, 0, 0, 0, 0}
+};
+
+static tone_gen_descriptor_t my_mf_digit_tones[16];
+
+static char r2_mf_tone_codes[] = "1234567890BCDEF";
+
+static void my_mf_gen_init(float low_fudge,
+                           int low_level,
+                           float high_fudge,
+                           int high_level,
+                           int duration,
+                           int fwd)
+{
+    const mf_digit_tones_t *tone;
+    int i;
+    
+    for (i = 0;  i < 15;  i++)
+    {
+        if (fwd)
+            tone = &r2_mf_fwd_tones[i];
+        else
+            tone = &r2_mf_back_tones[i];
+        make_tone_gen_descriptor(&my_mf_digit_tones[i],
+                                 tone->f1*(1.0 + low_fudge),
+                                 low_level,
+                                 tone->f2*(1.0 + high_fudge),
+                                 high_level,
+                                 duration,
+                                 0,
+                                 0,
+                                 0,
+                                 FALSE);
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static int my_mf_generate(int16_t amp[], char digit)
+{
+    int len;
+    char *cp;
+    tone_gen_state_t tone;
+
+    len = 0;
+    if ((cp = strchr(r2_mf_tone_codes, digit)))
+    {
+        tone_gen_init(&tone, &my_mf_digit_tones[cp - r2_mf_tone_codes]);
+        len += tone_gen(&tone, amp + len, 9999);
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void codec_munge(int16_t amp[], int len)
+{
+    int i;
+    uint8_t alaw;
+    
+    for (i = 0;  i < len;  i++)
+    {
+        alaw = linear_to_alaw (amp[i]);
+        amp[i] = alaw_to_linear (alaw);
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static int test_a_tone_set(int fwd)
+{
+    int i;
+    int j;
+    int len;
+    int sample;
+    const char *s;
+    char digit;
+    int actual;
+    int nplus;
+    int nminus;
+    float rrb;
+    float rcfo;
+    int16_t amp[100000];
+    r2_mf_rx_state_t mf_state;
+    awgn_state_t noise_source;
+    const mf_digit_tones_t *tone;
+
+    if (fwd)
+        tone = &r2_mf_fwd_tones[0];
+    else
+        tone = &r2_mf_back_tones[0];
+    r2_mf_rx_init(&mf_state, fwd);
+
+    /* Test 1: Mitel's test 1 isn't really a test. Its a calibration step,
+       which has no meaning here. */
+
+    printf ("Test 1: Calibration\n");
+    printf ("    Passed\n");
+
+    /* Test 2: Decode check
+       This is a sanity check, that all digits are reliably detected
+       under ideal conditions.  Each possible digit is repeated 10 times,
+       with 68ms bursts. The level of each tone is about 6dB down from clip */
+
+    printf ("Test 2: Decode check\n");
+    my_mf_gen_init(0.0, -3, 0.0, -3, 68, fwd);
+    s = r2_mf_tone_codes;
+    while (*s)
+    {
+        digit = *s++;
+        for (i = 0;  i < 10;  i++)
+        {
+            len = my_mf_generate(amp, digit);
+            codec_munge (amp, len);
+            actual = r2_mf_rx(&mf_state, amp, len);
+            if (actual != digit)
+            {
+                printf ("    Sent     '%c'\n", digit);
+                printf ("    Received 0x%X\n", actual);
+                printf ("    Failed\n");
+                exit (2);
+            }
+        }
+    }
+    printf ("    Passed\n");
+
+    /* Test 3: Recognition bandwidth and channel centre frequency check.
+       Use all digits. Each digit types requires four tests to complete
+       the check. Each section contains 40 pulses of 68ms duration,
+       with an amplitude of -20dB from clip per frequency.
+
+       Four sections covering the tests for one tone (1 digit) are:
+       a. H frequency at 0% deviation from center, L frequency at +0.1%.
+          L frequency is then increments in +01.% steps up to +4%. The
+          number of tone bursts is noted and designated N+.
+       b. H frequency at 0% deviation, L frequency at -0.1%. L frequency
+          is then incremental in -0.1% steps, up to -4%. The number of
+          tone bursts is noted and designated N-.
+       c. The test in (a) is repeated with the L frequency at 0% and the
+          H frequency varied up to +4%.
+       d. The test in (b) is repeated with the L frequency and 0% and the
+          H frequency varied to -4%.
+
+       Receiver Recognition Bandwidth (RRB) is calculated as follows:
+            RRB% = (N+ + N-)/10
+       Receiver Center Frequency Offset (RCFO) is calculated as follows:
+            RCFO% = X + (N+ - N-)/20
+            
+       Note that this test doesn't test what it says it is testing at all,
+       and the results are quite inaccurate, if not a downright lie! However,
+       it follows the Mitel procedure, so how can it be bad? :)
+       
+       The spec calls for +-4 +-10Hz (ie +-14Hz) of bandwidth. */
+
+    printf ("Test 3: Recognition bandwidth and channel centre frequency check\n");
+    s = r2_mf_tone_codes;
+    j = 0;
+    while (*s)
+    {
+        digit = *s++;
+        for (nplus = 0, i = 1;  i <= 60;  i++)
+        {
+            my_mf_gen_init((float) i/1000.0, -17, 0.0, -17, 68, fwd);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nplus++;
+        }
+        for (nminus = 0, i = -1;  i >= -60;  i--)
+        {
+            my_mf_gen_init((float) i/1000.0, -17, 0.0, -17, 68, fwd);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nminus++;
+        }
+        rrb = (float) (nplus + nminus)/10.0;
+        rcfo = (float) (nplus - nminus)/10.0;
+        printf ("    %c (low)  rrb = %5.2f%%, rcfo = %5.2f%%, max -ve = %5.2f, max +ve = %5.2f\n",
+                digit,
+                rrb,
+                rcfo,
+                (float) nminus/10.0,
+                (float) nplus/10.0);
+
+        if (rrb < rcfo + (2.0*100.0*14.0/r2_mf_fwd_tones[j].f1)  ||  rrb >= 15.0 + rcfo)
+        {
+            printf ("    Failed\n");
+            exit (2);
+        }
+
+        for (nplus = 0, i = 1;  i <= 60;  i++)
+        {
+            my_mf_gen_init(0.0, -17, (float) i/1000.0, -17, 68, fwd);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nplus++;
+        }
+        for (nminus = 0, i = -1;  i >= -60;  i--)
+        {
+            my_mf_gen_init(0.0, -17, (float) i/1000.0, -17, 68, fwd);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nminus++;
+        }
+        rrb = (float) (nplus + nminus)/10.0;
+        rcfo = (float) (nplus - nminus)/10.0;
+        printf ("    %c (high) rrb = %5.2f%%, rcfo = %5.2f%%, max -ve = %5.2f, max +ve = %5.2f\n",
+                digit,
+                rrb,
+                rcfo,
+                (float) nminus/10.0,
+                (float) nplus/10.0);
+        if (rrb < rcfo + (2.0*100.0*14.0/r2_mf_fwd_tones[j].f2)  ||  rrb >= 15.0 + rcfo)
+        {
+            printf ("    Failed\n");
+            exit (2);
+        }
+        j++;
+    }
+    printf ("    Passed\n");
+
+    /* Test 4: Acceptable amplitude ratio (twist).
+       Twist all digits in both directions, and check the maximum twist
+       we can accept. The way this is done is styled after the Mitel DTMF
+       test, and has good and bad points. */
+
+    printf ("Test 4: Acceptable amplitude ratio (twist)\n");
+    s = r2_mf_tone_codes;
+    while (*s)
+    {
+        digit = *s++;
+        for (nplus = 0, i = -50;  i >= -250;  i--)
+        {
+            my_mf_gen_init(0.0, -5, 0.0, i/10, 68, fwd);
+
+            len = my_mf_generate(amp, digit);
+            codec_munge (amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nplus++;
+        }
+        printf ("    %c normal twist  = %.2fdB\n", digit, (float) nplus/10.0);
+        if (nplus < 70)
+        {
+            printf ("    Failed\n");
+            exit (2);
+        }
+        for (nminus = 0, i = -50;  i >= -250;  i--)
+        {
+            my_mf_gen_init(0.0, i/10, 0.0, -5, 68, fwd);
+
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            if (r2_mf_rx(&mf_state, amp, len) == digit)
+                nminus++;
+        }
+        printf ("    %c reverse twist = %.2fdB\n", digit, (float) nminus/10.0);
+        if (nminus < 70)
+        {
+            printf ("    Failed\n");
+            exit (2);
+        }
+    }
+    printf ("    Passed\n");
+
+    /* Test 5: Dynamic range
+       This test sends all possible digits, with gradually increasing 
+       amplitude. We determine the span over which we achieve reliable
+       detection. */
+       
+    printf ("Test 5: Dynamic range\n");
+    for (nplus = nminus = -1000, i = -50;  i <= 3;  i++)
+    {
+        s = r2_mf_tone_codes;
+        while (*s)
+        {
+            digit = *s++;
+            my_mf_gen_init(0.0, i, 0.0, i, 68, fwd);
+            for (j = 0;  j < 100;  j++)
+            {
+                len = my_mf_generate(amp, digit);
+                codec_munge(amp, len);
+                if (r2_mf_rx(&mf_state, amp, len) != digit)
+                    break;
+            }
+            if (j < 100)
+                break;
+        }
+        if (j == 100)
+        {
+            if (nplus == -1000)
+                nplus = i;
+        }
+        else
+        {
+            if (nplus != -1000  &&  nminus == -1000)
+                nminus = i;
+        }
+    }
+    printf ("    Dynamic range = %ddB to %ddB\n", nplus, nminus - 1);
+    if (nplus > -35  ||  nminus <= -5)
+    {
+        printf("    Failed\n");
+        exit(2);
+    }
+    printf ("    Passed\n");
+
+    /* Test 6: Guard time
+       This test sends all possible digits, with a gradually reducing 
+       duration. */
+
+    printf ("Test 6: Guard time\n");
+    for (i = 30;  i < 62;  i++)
+    {
+        s = r2_mf_tone_codes;
+        j = 0;
+        while (*s)
+        {
+            digit = *s++;
+            my_mf_gen_init(0.0, -5, 0.0, -3, i, fwd);
+            for (j = 0;  j < 500;  j++)
+            {
+                len = my_mf_generate(amp, digit);
+                codec_munge(amp, len);
+                if (r2_mf_rx(&mf_state, amp, len) != digit)
+                    break;
+            }
+            if (j < 500)
+                break;
+        }
+        if (j == 500)
+            break;
+    }
+    printf ("    Guard time = %dms\n", i);
+    if (i > 61)
+    {
+        printf("    Failed\n");
+        exit(2);
+    }
+    printf ("    Passed\n");
+
+    /* Test 7: Acceptable signal to noise ratio
+       We send all possible digits at -6dBm from clip, mixed with AWGN.
+       We gradually reduce the noise until we get clean detection. */
+
+    printf ("Test 7: Acceptable signal to noise ratio\n");
+    my_mf_gen_init(0.0, -3, 0.0, -3, 68, fwd);
+    for (i = -3;  i > -50;  i--)
+    {
+        s = r2_mf_tone_codes;
+        while (*s)
+        {
+            digit = *s++;
+            awgn_init_dbm0(&noise_source, 1234567, (float) i);
+            for (j = 0;  j < 500;  j++)
+            {
+                len = my_mf_generate(amp, digit);
+                for (sample = 0;  sample < len;  sample++)
+                    amp[sample] = saturate(amp[sample] + awgn(&noise_source));
+                codec_munge(amp, len);
+                if (r2_mf_rx(&mf_state, amp, len) != digit)
+                    break;
+            }
+            if (j < 500)
+                break;
+        }
+        if (j == 500)
+            break;
+    }
+    printf("    Acceptable S/N ratio is %ddB\n", -3 - i);
+    if (-3 - i > 26)
+    {
+        printf("    Failed\n");
+        exit(2);
+    }
+    printf("    Passed\n");
+
+    /* The remainder of the Mitel tape is the talk-off test. This is
+       meaningless for R2 MF. However the decoder's tolerance of
+       out of band noise is significant. */
+    /* TODO: add a OOB tolerance test. */
+    
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+int main (int argc, char *argv[])
+{
+    time_t now;
+    time_t duration;
+
+    now = time(NULL);
+    printf("R2 forward tones\n");
+    test_a_tone_set(TRUE);
+    printf("R2 backward tones\n");
+    test_a_tone_set(FALSE);
+    duration = time(NULL) - now;
+    printf ("Tests passed in %lds\n", duration);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/