--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/tests/bell_mf_rx_tests.c	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,554 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * bell_mf_tests.c - Test the Bell 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: bell_mf_rx_tests.c,v 1.16 2009/05/30 15:23:13 steveu Exp $
+ */
+
+/*! \file */
+
+/*! \page bell_mf_tests_page Bell MF tone generation and detection tests
+\section bell_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 Bell MF, but make a
+fair starting point for a set of meaningful tests of Bell 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.
+*/
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <string.h>
+#include <time.h>
+#include <sndfile.h>
+
+//#if defined(WITH_SPANDSP_INTERNALS)
+#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
+//#endif
+
+#include "spandsp.h"
+
+/* Basic Bell MF specs:
+ *
+ * Signal generation:
+ *   Tone on time = KP: 100+-7ms. All other signals: 68+-7ms
+ *   Tone off time (between digits) = 68+-7ms
+ *   Frequency tolerance +- 1.5%
+ *   Signal level -7+-1dBm per frequency
+ *
+ * Signal reception:
+ *   Frequency tolerance +- 1.5% +-10Hz
+ *   Signal level -14dBm to 0dBm
+ *   Perform a "two and only two tones present" test.
+ *   Twist <= 6dB accepted
+ *   Receiver sensitive to signals above -22dBm per frequency
+ *   Test for a minimum of 55ms if KP, or 30ms of other signals.
+ *   Signals to be recognised if the two tones arrive within 8ms of each other.
+ *   Invalid signals result in the return of the re-order tone.
+ */
+
+#define MF_DURATION                 (68*8)
+#define MF_PAUSE                    (68*8)
+#define MF_CYCLE                    (MF_DURATION + MF_PAUSE)
+
+/*!
+    MF tone descriptor for tests.
+*/
+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 bell_mf_tones[] =
+{
+    { 700.0,  900.0, -7, -7,  68, 68},
+    { 700.0, 1100.0, -7, -7,  68, 68},
+    { 900.0, 1100.0, -7, -7,  68, 68},
+    { 700.0, 1300.0, -7, -7,  68, 68},
+    { 900.0, 1300.0, -7, -7,  68, 68},
+    {1100.0, 1300.0, -7, -7,  68, 68},
+    { 700.0, 1500.0, -7, -7,  68, 68},
+    { 900.0, 1500.0, -7, -7,  68, 68},
+    {1100.0, 1500.0, -7, -7,  68, 68},
+    {1300.0, 1500.0, -7, -7,  68, 68},
+    { 700.0, 1700.0, -7, -7,  68, 68}, /* ST''' - use 'C' */
+    { 900.0, 1700.0, -7, -7,  68, 68}, /* ST'   - use 'A' */
+    {1100.0, 1700.0, -7, -7, 100, 68}, /* KP    - use '*' */
+    {1300.0, 1700.0, -7, -7,  68, 68}, /* ST''  - use 'B' */
+    {1500.0, 1700.0, -7, -7,  68, 68}, /* ST    - use '#' */
+    {0.0, 0.0, 0, 0, 0, 0}
+};
+
+static tone_gen_descriptor_t my_mf_digit_tones[16];
+
+static char bell_mf_tone_codes[] = "1234567890CA*B#";
+
+int callback_ok;
+int callback_roll;
+
+static void my_mf_gen_init(float low_fudge,
+                           int low_level,
+                           float high_fudge,
+                           int high_level,
+                           int duration,
+                           int gap)
+{
+    int i;
+
+    /* The fiddle factor on the tone duration is to make KP consistently
+       50% longer than the other digits, as the digit durations are varied
+       for the tests. This is an approximation, as the real scaling should
+       be 100/68 */
+    for (i = 0;  i < 15;  i++)
+    {
+        make_tone_gen_descriptor(&my_mf_digit_tones[i],
+                                 bell_mf_tones[i].f1*(1.0 + low_fudge),
+                                 low_level,
+                                 bell_mf_tones[i].f2*(1.0 + high_fudge),
+                                 high_level,
+                                 (i == 12)  ?  3*duration/2  :  duration,
+                                 gap,
+                                 0,
+                                 0,
+                                 FALSE);
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static int my_mf_generate(int16_t amp[], const char *digits)
+{
+    int len;
+    char *cp;
+    tone_gen_state_t tone;
+
+    len = 0;
+    while (*digits)
+    {
+        if ((cp = strchr(bell_mf_tone_codes, *digits)))
+        {
+            tone_gen_init(&tone, &my_mf_digit_tones[cp - bell_mf_tone_codes]);
+            len += tone_gen(&tone, amp + len, 9999);
+        }
+        digits++;
+    }
+    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 --------------------------------------------------------*/
+
+#define ALL_POSSIBLE_DIGITS     "1234567890CA*B#"
+
+static void digit_delivery(void *data, const char *digits, int len)
+{
+    int i;
+    int seg;
+    const char *s = ALL_POSSIBLE_DIGITS;
+    const char *t;
+
+    if (data != (void *) 0x12345678)
+    {
+        callback_ok = FALSE;
+        return;
+    }
+    callback_ok = TRUE;
+    t = s + callback_roll;
+    seg = 15 - callback_roll;
+    for (i = 0;  i < len;  i += seg, seg = 15)
+    {
+        if (i + seg > len)
+            seg = len - i;
+        if (memcmp(digits + i, t, seg))
+        {
+            callback_ok = FALSE;
+            printf("Fail at %d %d\n", i, seg);
+            break;
+        }
+        t = s;
+        callback_roll = (callback_roll + seg)%15;
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static int16_t amp[1000000];
+
+int main(int argc, char *argv[])
+{
+    int duration;
+    int i;
+    int j;
+    int len;
+    int sample;
+    const char *s;
+    char digit[2];
+    char buf[MAX_BELL_MF_DIGITS + 1];
+    int actual;
+    int nplus;
+    int nminus;
+    float rrb;
+    float rcfo;
+    time_t now;
+    bell_mf_rx_state_t *mf_state;
+    awgn_state_t noise_source;
+
+    time(&now);
+    mf_state = bell_mf_rx_init(NULL, NULL, NULL);
+
+    /* 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, 68);
+    s = ALL_POSSIBLE_DIGITS;
+    digit[1] = '\0';
+    while (*s)
+    {
+        digit[0] = *s++;
+        for (i = 0;  i < 10;  i++)
+        {
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            actual = bell_mf_rx_get(mf_state, buf, 128);
+            if (actual != 1  ||  buf[0] != digit[0])
+            {
+                printf ("    Sent     '%s'\n", digit);
+                printf ("    Received '%s' [%d]\n", buf, 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 +-1.5% +-10Hz of bandwidth.
+    */
+    printf ("Test 3: Recognition bandwidth and channel centre frequency check\n");
+    s = ALL_POSSIBLE_DIGITS;
+    digit[1] = '\0';
+    j = 0;
+    while (*s)
+    {
+        digit[0] = *s++;
+        for (nplus = 0, i = 1;  i <= 60;  i++)
+        {
+            my_mf_gen_init((float) i/1000.0, -17, 0.0, -17, 68, 68);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nplus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        for (nminus = 0, i = -1;  i >= -60;  i--)
+        {
+            my_mf_gen_init((float) i/1000.0, -17, 0.0, -17, 68, 68);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nminus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        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[0],
+                rrb,
+                rcfo,
+                (float) nminus/10.0,
+                (float) nplus/10.0);
+
+        if (rrb < 3.0 + rcfo + (2.0*100.0*10.0/bell_mf_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, 68);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nplus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        for (nminus = 0, i = -1;  i >= -60;  i--)
+        {
+            my_mf_gen_init(0.0, -17, (float) i/1000.0, -17, 68, 68);
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nminus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        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[0],
+                rrb,
+                rcfo,
+                (float) nminus/10.0,
+                (float) nplus/10.0);
+        if (rrb < 3.0 + rcfo + (2.0*100.0*10.0/bell_mf_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 = ALL_POSSIBLE_DIGITS;
+    digit[1] = '\0';
+    while (*s)
+    {
+        digit[0] = *s++;
+        for (nplus = 0, i = -50;  i >= -250;  i--)
+        {
+            my_mf_gen_init(0.0, -5, 0.0, i/10, 68, 68);
+
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nplus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        printf("    %c normal twist  = %.2fdB\n", digit[0], (float) nplus/10.0);
+        if (nplus < 60)
+        {
+            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, 68);
+
+            len = my_mf_generate(amp, digit);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            nminus += bell_mf_rx_get(mf_state, buf, 128);
+        }
+        printf("    %c reverse twist = %.2fdB\n", digit[0], (float) nminus/10.0);
+        if (nminus < 60)
+        {
+            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. The spec says we should detect between -14dBm and 0dBm,
+       but the tones clip above -3dBm, so this cannot really work. */
+       
+    printf("Test 5: Dynamic range\n");
+    for (nplus = nminus = -1000, i = -50;  i <= 3;  i++)
+    {
+        my_mf_gen_init(0.0, i, 0.0, i, 68, 68);
+        for (j = 0;  j < 100;  j++)
+        {
+            len = my_mf_generate(amp, ALL_POSSIBLE_DIGITS);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            if (bell_mf_rx_get(mf_state, buf, 128) != 15)
+                break;
+            if (strcmp(buf, ALL_POSSIBLE_DIGITS) != 0)
+                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 > -22  ||  nminus <= -3)
+    {
+        printf("    Failed\n");
+        exit(2);
+    }
+    printf("    Passed\n");
+
+    /* Test 6: Guard time
+       This test sends all possible digits, with a gradually reducing 
+       duration. The spec defines a narrow range of tone duration
+       times we can expect, so as long as we detect reliably at the
+       specified minimum we should be OK. However, the spec also says
+       we should detect on a minimum of 55ms of KP, or 30ms of other
+       digits. */
+
+    printf("Test 6: Guard time\n");
+    for (i = 30;  i < 62;  i++)
+    {
+        my_mf_gen_init(0.0, -5, 0.0, -3, i, 68);
+        for (j = 0;  j < 500;  j++)
+        {
+            len = my_mf_generate(amp, ALL_POSSIBLE_DIGITS);
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            if (bell_mf_rx_get(mf_state, buf, 128) != 15)
+                break;
+            if (strcmp(buf, ALL_POSSIBLE_DIGITS) != 0)
+                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, 68);
+    for (i = -10;  i > -50;  i--)
+    {
+        awgn_init_dbm0(&noise_source, 1234567, (float) i);
+        for (j = 0;  j < 500;  j++)
+        {
+            len = my_mf_generate(amp, ALL_POSSIBLE_DIGITS);
+            for (sample = 0;  sample < len;  sample++)
+                amp[sample] = saturate(amp[sample] + awgn(&noise_source));
+            codec_munge(amp, len);
+            bell_mf_rx(mf_state, amp, len);
+            if (bell_mf_rx_get(mf_state, buf, 128) != 15)
+                break;
+            if (strcmp(buf, ALL_POSSIBLE_DIGITS) != 0)
+                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 Bell MF. However the decoder's tolerance of
+       out of band noise is significant. */
+    /* TODO: add a OOB tolerance test. */
+
+    /* Test the callback mode for delivering detected digits */
+
+    printf("Test: Callback digit delivery mode.\n");
+    callback_ok = FALSE;
+    callback_roll = 0;
+    mf_state = bell_mf_rx_init(NULL, digit_delivery, (void *) 0x12345678);
+    my_mf_gen_init(0.0, -10, 0.0, -10, 68, 68);
+    for (i = 1;  i < 10;  i++)
+    {
+        len = 0;
+        for (j = 0;  j < i;  j++)
+            len += my_mf_generate(amp + len, ALL_POSSIBLE_DIGITS);
+        bell_mf_rx(mf_state, amp, len);
+        if (!callback_ok)
+            break;
+    }
+    if (!callback_ok)
+    {
+        printf("    Failed\n");
+     	exit (2);
+    }
+    printf("    Passed\n");
+
+    duration = time (NULL) - now;
+    printf ("Tests passed in %ds\n", duration);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/