--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/v8.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,880 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * v8.c - V.8 modem negotiation processing.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2004 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: v8.c,v 1.20 2006/11/30 15:41:47 steveu Exp $
+ */
+ 
+/*! \file */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <memory.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+
+#include "spandsp/telephony.h"
+#include "spandsp/logging.h"
+#include "spandsp/queue.h"
+#include "spandsp/async.h"
+#include "spandsp/dds.h"
+#include "spandsp/tone_detect.h"
+#include "spandsp/tone_generate.h"
+#include "spandsp/super_tone_rx.h"
+#include "spandsp/modem_connect_tones.h"
+#include "spandsp/power_meter.h"
+#include "spandsp/fsk.h"
+#include "spandsp/v8.h"
+
+#define ms_to_samples(t)    (((t)*SAMPLE_RATE)/1000)
+
+enum
+{
+    V8_WAIT_1S,
+    V8_CI,
+    V8_CI_ON,
+    V8_CI_OFF,
+    V8_HEARD_ANSAM,
+    V8_CM_ON,
+    V8_CJ_ON,
+    V8_CM_WAIT,
+
+    V8_SIGC,
+    V8_WAIT_200MS,
+    V8_JM_ON,
+    V8_SIGA,
+
+    V8_PARKED
+} v8_states_e;
+
+enum
+{
+    V8_SYNC_UNKNOWN = 0,
+    V8_SYNC_CI,
+    V8_SYNC_CM_JM,
+    V8_SYNC_V92
+} v8_sync_types_e;
+
+const char *v8_call_function_to_str(int call_function)
+{
+    switch (call_function)
+    {
+    case V8_CALL_TBS:
+        return "TBS";
+    case V8_CALL_H324:
+        return "H.324 PSTN multimedia terminal";
+    case V8_CALL_V18:
+        return "V.18 textphone";
+    case V8_CALL_T101:
+        return "T.101 videotext";
+    case V8_CALL_T30_TX:
+        return "T.30 Tx FAX";
+    case V8_CALL_T30_RX:
+        return "T.30 Rx FAX";
+    case V8_CALL_V_SERIES:
+        return "V series modem data";
+    case V8_CALL_FUNCTION_EXTENSION:
+        return "Call function is in extention octet";
+    }
+    return "???";
+}
+/*- End of function --------------------------------------------------------*/
+
+const char *v8_modulation_to_str(int modulation_scheme)
+{
+    switch (modulation_scheme)
+    {
+    case V8_MOD_V17:
+        return "V.17 half-duplex";
+    case V8_MOD_V21:
+        return "V.21 duplex";
+    case V8_MOD_V22:
+        return "V.22/V22.bis duplex";
+    case V8_MOD_V23HALF:
+        return "V.23 half-duplex";
+    case V8_MOD_V23:
+        return "V.23 duplex";
+    case V8_MOD_V26BIS:
+        return "V.23 duplex";
+    case V8_MOD_V26TER:
+        return "V.23 duplex";
+    case V8_MOD_V27TER:
+        return "V.23 duplex";
+    case V8_MOD_V29:
+        return "V.29 half-duplex";
+    case V8_MOD_V32:
+        return "V.32/V32.bis duplex";
+    case V8_MOD_V34HALF:
+        return "V.34 half-duplex";
+    case V8_MOD_V34:
+        return "V.34 duplex";
+    case V8_MOD_V90:
+        return "V.90 duplex";
+    case V8_MOD_V92:
+        return "V.92 duplex";
+    case V8_MOD_FAILED:
+        return "negotiation failed";
+    }
+    return "???";
+}
+/*- End of function --------------------------------------------------------*/
+
+const char *v8_protocol_to_str(int protocol)
+{
+    switch (protocol)
+    {
+    case V8_PROTOCOL_NONE:
+        return "None";
+    case V8_PROTOCOL_LAPM_V42:
+        return "LAPM";
+    case V8_PROTOCOL_EXTENSION:
+        return "Extension";
+    }
+    return "Undefined";
+}
+/*- End of function --------------------------------------------------------*/
+
+const char *v8_pstn_access_to_str(int pstn_access)
+{
+    return "???";
+}
+/*- End of function --------------------------------------------------------*/
+
+const char *v8_pcm_modem_availability_to_str(int pcm_modem_availability)
+{
+    return "???";
+}
+/*- End of function --------------------------------------------------------*/
+
+void v8_log_supported_modulations(v8_state_t *s, int modulation_schemes)
+{
+    const char *comma;
+    int i;
+    
+    comma = "";
+    span_log(&s->logging, SPAN_LOG_FLOW, "");
+    for (i = 0;  i < 32;  i++)
+    {
+        if ((modulation_schemes & (1 << i)))
+        {
+            span_log(&s->logging, SPAN_LOG_FLOW | SPAN_LOG_SUPPRESS_LABELLING, "%s%s", comma, v8_modulation_to_str(modulation_schemes & (1 << i)));
+            comma = ", ";
+        }
+    }
+    span_log(&s->logging, SPAN_LOG_FLOW | SPAN_LOG_SUPPRESS_LABELLING, " supported\n");
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_call_function(v8_state_t *s, const uint8_t *p)
+{
+    int call_function;
+
+    call_function = (*p >> 5) & 0x07;
+    span_log(&s->logging, SPAN_LOG_FLOW, "%s\n", v8_call_function_to_str(call_function));
+    s->call_function = call_function;
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_modulation_mode(v8_state_t *s, const uint8_t *p)
+{
+    int far_end_modulations;
+
+    /* Modulation mode octet */
+    far_end_modulations = 0;
+    if (*p & 0x80)
+        far_end_modulations |= V8_MOD_V34HALF;
+    if (*p & 0x40)
+        far_end_modulations |= V8_MOD_V34;
+    if (*p & 0x20)
+        far_end_modulations |= V8_MOD_V90;
+
+    if ((*++p & 0x38) == 0x10)
+    {
+        if (*p & 0x80)
+            far_end_modulations |= V8_MOD_V27TER;
+        if (*p & 0x40)
+            far_end_modulations |= V8_MOD_V29;
+        if (*p & 0x04)
+            far_end_modulations |= V8_MOD_V17;
+        if (*p & 0x02)
+            far_end_modulations |= V8_MOD_V22;
+        if (*p & 0x01)
+            far_end_modulations |= V8_MOD_V32;
+
+        if ((*++p & 0x38) == 0x10)
+        {
+            if (*p & 0x80)
+                far_end_modulations |= V8_MOD_V21;
+            if (*p & 0x40)
+                far_end_modulations |= V8_MOD_V23HALF;
+            if (*p & 0x04)
+                far_end_modulations |= V8_MOD_V23;
+            if (*p & 0x02)
+                far_end_modulations |= V8_MOD_V26BIS;
+            if (*p & 0x01)
+                far_end_modulations |= V8_MOD_V26TER;
+            /* Skip any future extensions we do not understand */
+            while  ((*++p & 0x38) == 0x10)
+                /* dummy loop */;
+        }
+    }
+    s->far_end_modulations = far_end_modulations;
+    v8_log_supported_modulations(s, s->far_end_modulations);
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_protocols(v8_state_t *s, const uint8_t *p)
+{
+    int protocol;
+
+    protocol = (*p >> 5) & 0x07;
+    span_log(&s->logging, SPAN_LOG_FLOW, "%s\n", v8_protocol_to_str(protocol));
+    s->protocol = protocol;
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_pstn_access(v8_state_t *s, const uint8_t *p)
+{
+    int pstn_access;
+
+    pstn_access = (*p >> 5) & 0x07;
+    if (pstn_access & V8_PSTN_ACCESS_DCE_ON_DIGTIAL)
+        span_log(&s->logging, SPAN_LOG_FLOW, "DCE on digital network connection\n");
+    else
+        span_log(&s->logging, SPAN_LOG_FLOW, "DCE on analogue network connection\n");
+    if (pstn_access & V8_PSTN_ACCESS_ANSWER_DCE_CELLULAR)
+        span_log(&s->logging, SPAN_LOG_FLOW, "Answer DCE on cellular connection\n");
+    if (pstn_access & V8_PSTN_ACCESS_CALL_DCE_CELLULAR)
+        span_log(&s->logging, SPAN_LOG_FLOW, "Call DCE on cellular connection\n");
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_non_standard_facilities(v8_state_t *s, const uint8_t *p)
+{
+    ++p;
+    p += *p;
+    return p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_pcm_modem_availability(v8_state_t *s, const uint8_t *p)
+{
+    int pcm_availability;
+
+    pcm_availability = (*p >> 5) & 0x07;
+    if (pcm_availability & V8_PSTN_PCM_MODEM_V91)
+        span_log(&s->logging, SPAN_LOG_FLOW, "V.91 available\n");
+    if (pcm_availability & V8_PSTN_PCM_MODEM_V90_V92_DIGITAL)
+        span_log(&s->logging, SPAN_LOG_FLOW, "V.90 or V.92 digital modem available\n");
+    if (pcm_availability & V8_PSTN_PCM_MODEM_V90_V92_ANALOGUE)
+        span_log(&s->logging, SPAN_LOG_FLOW, "V.90 or V.92 analogue modem available\n");
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static const uint8_t *process_t66(v8_state_t *s, const uint8_t *p)
+{
+    return ++p;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void ci_decode(v8_state_t *s)
+{
+    if ((s->rx_data[0] & 0x1F) == 0x01)
+        process_call_function(s, &s->rx_data[0]);
+}
+/*- End of function --------------------------------------------------------*/
+
+static void cm_jm_decode(v8_state_t *s)
+{
+    const uint8_t *p;
+
+    if (s->got_cm_jm)
+        return;
+
+    /* We must receive two consecutive identical CM or JM sequences to accept it. */
+    if (s->cm_jm_count <= 0
+        ||
+        s->cm_jm_count != s->rx_data_ptr
+        ||
+        memcmp(s->cm_jm_data, s->rx_data, s->rx_data_ptr))
+    {
+        /* Save the current CM or JM sequence */
+        s->cm_jm_count = s->rx_data_ptr;
+        memcpy(s->cm_jm_data, s->rx_data, s->rx_data_ptr);
+        return;
+    }
+    /* We have a pair of matching CMs or JMs */
+    s->got_cm_jm = TRUE;
+
+    span_log(&s->logging, SPAN_LOG_FLOW, "Decoding\n");
+
+    /* Zero indicates the end */
+    s->cm_jm_data[s->cm_jm_count] = 0;
+
+    s->far_end_modulations = 0;
+    p = s->cm_jm_data;
+
+    while (*p)
+    {
+        switch (*p & 0x1F)
+        {
+        case 0x01:
+            p = process_call_function(s, p);
+            break;
+        case 0x05:
+            p = process_modulation_mode(s, p);
+            break;
+        case 0x0A:
+            p = process_protocols(s, p);
+            break;
+        case 0x0D:
+            p = process_pstn_access(s, p);
+            break;
+        case 0x0F:
+            p = process_non_standard_facilities(s, p);
+            break;
+        case 0x07:
+            p = process_pcm_modem_availability(s, p);
+            break;
+        case 0x0E:
+            p = process_t66(s, p);
+            break;
+        default:
+            p++;
+            break;
+        }
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static void put_bit(void *user_data, int bit)
+{
+    v8_state_t *s;
+    int new_preamble_type;
+    const char *tag;
+    uint8_t data;
+
+    s = user_data;
+    if (bit < 0)
+    {
+        /* Special conditions */
+        switch (bit)
+        {
+        case PUTBIT_CARRIER_UP:
+        case PUTBIT_CARRIER_DOWN:
+        case PUTBIT_TRAINING_SUCCEEDED:
+        case PUTBIT_TRAINING_FAILED:
+            break;
+        default:
+            break;
+        }
+        return;
+    }
+    /* Wait until we sync. */
+    s->bit_stream = (s->bit_stream >> 1) | (bit << 19);
+    if (s->bit_stream == 0x803FF)
+        new_preamble_type = V8_SYNC_CI;
+    else if (s->bit_stream == 0xF03FF)
+        new_preamble_type = V8_SYNC_CM_JM;
+    else if (s->bit_stream == 0xAABFF)
+        new_preamble_type = V8_SYNC_V92;
+    else
+        new_preamble_type = V8_SYNC_UNKNOWN;
+    if (new_preamble_type)
+    {
+        /* Debug */
+        if (span_log_test(&s->logging, SPAN_LOG_FLOW))
+        {
+            if (s->preamble_type == V8_SYNC_CI)
+            {
+                tag = "CI: ";
+            }
+            else if (s->preamble_type == V8_SYNC_CM_JM)
+            {
+                if (s->caller)
+                    tag = "JM: ";
+                else
+                    tag = "CM: ";
+            }
+            else if (s->preamble_type == V8_SYNC_V92)
+            {
+                tag = "V92: ";
+            }
+            else
+            {
+                tag = "??: ";
+            }
+            span_log_buf(&s->logging, SPAN_LOG_FLOW, tag, s->rx_data, s->rx_data_ptr);
+        }
+        /* Decode previous sequence */
+        switch (s->preamble_type)
+        {
+        case V8_SYNC_CI:
+            ci_decode(s);
+            break;
+        case V8_SYNC_CM_JM:
+            cm_jm_decode(s);
+            break;
+        }
+        s->preamble_type = new_preamble_type;
+        s->bit_cnt = 0;
+        s->rx_data_ptr = 0;
+    }
+    
+    /* Parse octets with 1 bit start, 1 bit stop */
+    if (s->preamble_type)
+    {
+        s->bit_cnt++;
+        /* Start, stop? */
+        if ((s->bit_stream & 0x80400) == 0x80000  &&  s->bit_cnt >= 10)
+        {
+            /* Store the available data */
+            data = (uint8_t) ((s->bit_stream >> 11) & 0xFF);
+            /* CJ detection */
+            if (data == 0)
+            {
+                if (++s->zero_byte_count == 3)
+                    s->got_cj = TRUE;
+            }
+            else
+            {
+                s->zero_byte_count = 0;
+            }
+
+            if (s->rx_data_ptr < (int) (sizeof(s->rx_data) - 1))
+                s->rx_data[s->rx_data_ptr++] = data;
+            s->bit_cnt = 0;
+        }
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v8_decode_init(v8_state_t *s)
+{
+    if (s->caller)
+        fsk_rx_init(&s->v21rx, &preset_fsk_specs[FSK_V21CH2], FALSE, put_bit, s);
+    else
+        fsk_rx_init(&s->v21rx, &preset_fsk_specs[FSK_V21CH1], FALSE, put_bit, s);
+    s->preamble_type = 0;
+    s->bit_stream = 0;
+    s->cm_jm_count = 0;
+    s->got_cm_jm = FALSE;
+    s->got_cj = FALSE;
+    s->zero_byte_count = 0;
+    s->rx_data_ptr = 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int get_bit(void *user_data)
+{
+    v8_state_t *s;
+    uint8_t bit;
+
+    s = user_data;
+    if (queue_read(&s->tx_queue, &bit, 1) <= 0)
+        bit = 1;
+    return bit;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v8_put_byte(v8_state_t *s, int data)
+{
+    int i;
+    uint8_t bits[10];
+
+    /* Insert start & stop bits */
+    bits[0] = 0;
+    for (i = 1;  i < 9;  i++)
+    {
+        bits[i] = (uint8_t) (data & 1);
+        data >>= 1;
+    }
+    bits[9] = 1;
+    queue_write(&s->tx_queue, bits, 10);
+}
+/*- End of function --------------------------------------------------------*/
+
+static void send_cm_jm(v8_state_t *s, int mod_mask)
+{
+    int val;
+    static const uint8_t preamble[20] =
+    {
+        /* 10 1's (0x3FF), then 10 bits of CM sync (0x00F) */
+        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1
+    };
+
+    /* Send a CM, or a JM as appropriate */
+    queue_write(&s->tx_queue, preamble, 20);
+    
+    /* Data call */
+    v8_put_byte(s, (V8_CALL_V_SERIES << 5) | 0x01);
+    
+    /* Supported modulations */
+    val = 0x05;
+    if (mod_mask & V8_MOD_V90)
+        val |= 0x20;
+    if (mod_mask & V8_MOD_V34)
+        val |= 0x40;
+    v8_put_byte(s, val);
+
+    val = 0x10;
+    if (mod_mask & V8_MOD_V32)
+        val |= 0x01;
+    if (mod_mask & V8_MOD_V22)
+        val |= 0x02;
+    if (mod_mask & V8_MOD_V17)
+        val |= 0x04;
+    if (mod_mask & V8_MOD_V29)
+        val |= 0x40;
+    if (mod_mask & V8_MOD_V27TER)
+        val |= 0x80;
+    v8_put_byte(s, val);
+
+    val = 0x10;
+    if (mod_mask & V8_MOD_V26TER)
+        val |= 0x01;
+    if (mod_mask & V8_MOD_V26BIS)
+        val |= 0x02;
+    if (mod_mask & V8_MOD_V23)
+        val |= 0x04;
+    if (mod_mask & V8_MOD_V23HALF)
+        val |= 0x40;
+    if (mod_mask & V8_MOD_V21)
+        val |= 0x80;
+    v8_put_byte(s, val);
+
+    v8_put_byte(s, (0 << 5) | 0x07);
+
+    v8_put_byte(s, (V8_PROTOCOL_LAPM_V42 << 5) | 0x0A);
+
+    /* No cellular right now */    
+    v8_put_byte(s, (0 << 5) | 0x0D);
+}
+/*- End of function --------------------------------------------------------*/
+
+static int select_modulation(int mask)
+{
+    if (mask & V8_MOD_V90)
+        return V8_MOD_V90;
+    if (mask & V8_MOD_V34)
+        return V8_MOD_V34;
+    if (mask & V8_MOD_V32)
+        return V8_MOD_V32;
+    if (mask & V8_MOD_V23)
+        return V8_MOD_V23;
+    if (mask & V8_MOD_V21)
+        return V8_MOD_V21;
+    return V8_MOD_FAILED;
+}
+/*- End of function --------------------------------------------------------*/
+
+int v8_tx(v8_state_t *s, int16_t *amp, int max_len)
+{
+    int len;
+
+    //span_log(&s->logging, SPAN_LOG_FLOW, "v8_tx state %d\n", s->state);
+    len = 0;
+    switch (s->state)
+    {
+    case V8_CI_ON:
+    case V8_CM_ON:
+    case V8_JM_ON:
+    case V8_CJ_ON:
+        len = fsk_tx(&s->v21tx, amp, max_len);
+        break;
+    case V8_CM_WAIT:
+        /* Send the ANSam tone */
+        len = modem_connect_tones_tx(&s->ec_dis_tx, amp, max_len);
+        break;
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+int v8_rx(v8_state_t *s, const int16_t *amp, int len)
+{
+    int i;
+    int residual_samples;
+    v8_result_t result;
+    static const uint8_t preamble[20] =
+    {
+        /* 10 1's (0x3FF), then 10 bits of CI sync (0x001) */
+        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
+    };
+
+    //span_log(&s->logging, SPAN_LOG_FLOW, "v8_rx state %d\n", s->state);
+    residual_samples = 0;
+    switch (s->state)
+    {
+    case V8_WAIT_1S:
+        /* Wait 1 second before sending the first CI packet */
+        if ((s->negotiation_timer -= len) > 0)
+            break;
+        s->state = V8_CI;
+        s->ci_count = 0;
+        modem_connect_tones_rx_init(&s->ec_dis_rx, MODEM_CONNECT_TONES_EC_DISABLE, NULL, NULL);
+        fsk_tx_init(&s->v21tx, &preset_fsk_specs[FSK_V21CH1], get_bit, s);
+        /* Fall through to the next state */
+    case V8_CI:
+        residual_samples = modem_connect_tones_rx(&s->ec_dis_rx, amp, len);
+        /* Send 4 CI packets in a burst (the spec says at least 3) */
+        for (i = 0;  i < 4;  i++)
+        {
+            /* 10 1's (0x3FF), then CI sync (0x001) */
+            queue_write(&s->tx_queue, preamble, 20);
+            v8_put_byte(s, (V8_CALL_V_SERIES << 5) | 0x01);
+        }
+        s->state = V8_CI_ON;
+        break;
+    case V8_CI_ON:
+        residual_samples = modem_connect_tones_rx(&s->ec_dis_rx, amp, len);
+        if (queue_empty(&s->tx_queue))
+        {
+            s->state = V8_CI_OFF;
+            s->ci_timer = ms_to_samples(500);
+        }
+        break;
+    case V8_CI_OFF:
+        residual_samples = modem_connect_tones_rx(&s->ec_dis_rx, amp, len);
+        /* Check if an ANSam tone has been detected */
+        if (modem_connect_tones_rx_get(&s->ec_dis_rx))
+        {
+            /* Set the Te interval. The spec. says 500ms is the minimum,
+               but gives reasons why 1 second is a better value. */
+            s->ci_timer = ms_to_samples(1000);
+            s->state = V8_HEARD_ANSAM;
+            break;
+        }
+        if ((s->ci_timer -= len) <= 0)
+        {
+            if (++s->ci_count >= 10)
+            {
+                /* The spec says we should give up now. */
+                s->state = V8_PARKED;
+                if (s->result_handler)
+                    s->result_handler(s->result_handler_user_data, NULL);
+            }
+            else
+            {
+                /* Try again */
+                s->state = V8_CI;
+            }
+        }
+        break;
+    case V8_HEARD_ANSAM:
+        /* We have heard the ANSam signal, but we still need to wait for the
+           end of the Te timeout period to comply with the spec. */
+        if ((s->ci_timer -= len) <= 0)
+        {
+            v8_decode_init(s);
+            s->state = V8_CM_ON;
+            s->negotiation_timer = ms_to_samples(5000);
+            send_cm_jm(s, s->available_modulations);
+        }
+        break;
+    case V8_CM_ON:
+        residual_samples = fsk_rx(&s->v21rx, amp, len);
+        if (s->got_cm_jm)
+        {
+            /* Now JM has been detected we send CJ and wait for 75 ms
+               before finishing the V.8 analysis. */
+            s->negotiated_modulation = select_modulation(s->far_end_modulations);
+
+            queue_flush(&s->tx_queue);
+            for (i = 0;  i < 9;  i++)
+                v8_put_byte(s, 0);
+            s->state = V8_CJ_ON;
+            break;
+        }
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* Timeout */
+            s->state = V8_PARKED;
+            if (s->result_handler)
+                s->result_handler(s->result_handler_user_data, NULL);
+        }
+        if (queue_empty(&s->tx_queue))
+        {
+            /* Send CM again */
+            send_cm_jm(s, s->available_modulations);
+        }
+        break;
+    case V8_CJ_ON:
+        residual_samples = fsk_rx(&s->v21rx, amp, len);
+        if (queue_empty(&s->tx_queue))
+        {
+            s->negotiation_timer = ms_to_samples(75);
+            s->state = V8_SIGC;
+        }
+        break;
+    case V8_SIGC:
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* The V.8 negotiation has succeeded. */
+            s->state = V8_PARKED;
+            if (s->result_handler)
+            {
+                result.call_function = s->call_function;
+                result.available_modulations = s->far_end_modulations;
+                result.negotiated_modulation = s->negotiated_modulation;
+                result.protocol = s->protocol;
+                result.pstn_access = s->pstn_access;
+                result.nsf_seen = s->nsf_seen;
+                result.pcm_modem_availability = s->pcm_modem_availability;
+                result.t66_seen = s->t66_seen;
+                s->result_handler(s->result_handler_user_data, &result);
+            }
+        }
+        break;
+    case V8_WAIT_200MS:
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* Send the ANSam tone */
+            modem_connect_tones_tx_init(&s->ec_dis_tx, MODEM_CONNECT_TONES_EC_DISABLE_MOD);
+                
+            v8_decode_init(s);
+            s->state = V8_CM_WAIT;
+            s->negotiation_timer = ms_to_samples(5000);
+        }
+        break;
+    case V8_CM_WAIT:
+        residual_samples = fsk_rx(&s->v21rx, amp, len);
+        if (s->got_cm_jm)
+        {
+            /* Stop sending ANSam and send JM instead */
+            fsk_tx_init(&s->v21tx, &preset_fsk_specs[FSK_V21CH2], get_bit, s);
+            /* Set the timeout for JM */
+            s->negotiation_timer = ms_to_samples(5000); 
+            s->state = V8_JM_ON;
+            s->common_modulations = s->available_modulations & s->far_end_modulations;
+            s->negotiated_modulation = select_modulation(s->common_modulations);
+            send_cm_jm(s, s->common_modulations);
+            break;
+        }
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* Timeout */
+            s->state = V8_PARKED;
+            if (s->result_handler)
+                s->result_handler(s->result_handler_user_data, NULL);
+        }
+        break;
+    case V8_JM_ON:
+        residual_samples = fsk_rx(&s->v21rx, amp, len);
+        if (s->got_cj)
+        {
+            /* Stop sending JM, and wait 75 ms */
+            s->negotiation_timer = ms_to_samples(75);
+            s->state = V8_SIGA;
+            break;
+        }
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* Timeout */
+            s->state = V8_PARKED;
+            if (s->result_handler)
+                s->result_handler(s->result_handler_user_data, NULL);
+            break;
+        }
+        if (queue_empty(&s->tx_queue))
+        {
+            /* Send JM */
+            send_cm_jm(s, s->common_modulations);
+        }
+        break;
+    case V8_SIGA:
+        if ((s->negotiation_timer -= len) <= 0)
+        {
+            /* The V.8 negotiation has succeeded. */
+            s->state = V8_PARKED;
+            if (s->result_handler)
+            {
+                result.call_function = s->call_function;
+                result.available_modulations = s->far_end_modulations;
+                result.negotiated_modulation = s->negotiated_modulation;
+                result.protocol = s->protocol;
+                result.pstn_access = s->pstn_access;
+                result.nsf_seen = s->nsf_seen;
+                result.pcm_modem_availability = s->pcm_modem_availability;
+                result.t66_seen = s->t66_seen;
+                s->result_handler(s->result_handler_user_data, &result);
+            }
+        }
+        break;
+    case V8_PARKED:
+        residual_samples = len;
+        break;
+    }
+    return residual_samples;
+}
+/*- End of function --------------------------------------------------------*/
+
+v8_state_t *v8_init(v8_state_t *s,
+                    int caller,
+                    int available_modulations,
+                    v8_result_handler_t *result_handler,
+                    void *user_data)
+{
+    memset(s, 0, sizeof(*s));
+    s->caller = caller;
+    s->available_modulations = available_modulations;
+    s->result_handler = result_handler;
+    s->result_handler_user_data = user_data;
+
+    s->ci_timer = 0;
+    if (s->caller)
+    {
+        s->state = V8_WAIT_1S;
+        s->negotiation_timer = ms_to_samples(1000);
+    }
+    else
+    {
+        s->state = V8_WAIT_200MS;
+        s->negotiation_timer = ms_to_samples(200);
+    }
+    if (queue_create(&s->tx_queue, 1024, 0))
+        return NULL;
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+
+int v8_release(v8_state_t *s)
+{
+    return queue_delete(&s->tx_queue);
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/