--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/fax.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,617 @@
+//#define LOG_FAX_AUDIO
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * fax.c - Analogue line ITU T.30 FAX transfer processing
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003, 2005, 2006 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: fax.c,v 1.52 2006/11/19 14:07:24 steveu Exp $
+ */
+
+/*! \file */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+#include <assert.h>
+#include <fcntl.h>
+#include <time.h>
+#if defined(LOG_FAX_AUDIO)
+#include <unistd.h>
+#endif
+
+#include <tiffio.h>
+
+#include "spandsp/telephony.h"
+#include "spandsp/logging.h"
+#include "spandsp/queue.h"
+#include "spandsp/dc_restore.h"
+#include "spandsp/power_meter.h"
+#include "spandsp/complex.h"
+#include "spandsp/tone_generate.h"
+#include "spandsp/async.h"
+#include "spandsp/hdlc.h"
+#include "spandsp/silence_gen.h"
+#include "spandsp/fsk.h"
+#include "spandsp/v29rx.h"
+#include "spandsp/v29tx.h"
+#include "spandsp/v27ter_rx.h"
+#include "spandsp/v27ter_tx.h"
+#if defined(ENABLE_V17)
+#include "spandsp/v17rx.h"
+#include "spandsp/v17tx.h"
+#endif
+#include "spandsp/t4.h"
+
+#include "spandsp/t30_fcf.h"
+#include "spandsp/t35.h"
+#include "spandsp/t30.h"
+
+#include "spandsp/fax.h"
+
+static void fax_send_hdlc(void *user_data, const uint8_t *msg, int len)
+{
+    fax_state_t *s;
+
+    s = (fax_state_t *) user_data;
+    
+    hdlc_tx_frame(&(s->hdlctx), msg, len);
+    s->first_tx_hdlc_frame = FALSE;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int dummy_rx(void *s, const int16_t amp[], int len)
+{
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+#if defined(ENABLE_V17)
+static int early_v17_rx(void *user_data, const int16_t amp[], int len)
+{
+    fax_state_t *s;
+
+    s = (fax_state_t *) user_data;
+    v17_rx(&(s->v17rx), amp, len);
+    fsk_rx(&(s->v21rx), amp, len);
+    if (s->t30_state.rx_trained)
+    {
+        /* The fast modem has trained, so we no longer need to run the slow
+           one in parallel. */
+        span_log(&s->logging, SPAN_LOG_FLOW, "Switching from V.17 + V.21 to V.17 (%.2fdBm0)\n", v17_rx_signal_power(&(s->v17rx)));
+        s->rx_handler = (span_rx_handler_t *) &v17_rx;
+        s->rx_user_data = &(s->v17rx);
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+#endif
+
+static int early_v27ter_rx(void *user_data, const int16_t amp[], int len)
+{
+    fax_state_t *s;
+
+    s = (fax_state_t *) user_data;
+    v27ter_rx(&(s->v27ter_rx), amp, len);
+    fsk_rx(&(s->v21rx), amp, len);
+    if (s->t30_state.rx_trained)
+    {
+        /* The fast modem has trained, so we no longer need to run the slow
+           one in parallel. */
+        span_log(&s->logging, SPAN_LOG_FLOW, "Switching from V.27ter + V.21 to V.27ter (%.2fdBm0)\n", v27ter_rx_signal_power(&(s->v27ter_rx)));
+        s->rx_handler = (span_rx_handler_t *) &v27ter_rx;
+        s->rx_user_data = &(s->v27ter_rx);
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int early_v29_rx(void *user_data, const int16_t amp[], int len)
+{
+    fax_state_t *s;
+
+    s = (fax_state_t *) user_data;
+    v29_rx(&(s->v29rx), amp, len);
+    fsk_rx(&(s->v21rx), amp, len);
+    if (s->t30_state.rx_trained)
+    {
+        /* The fast modem has trained, so we no longer need to run the slow
+           one in parallel. */
+        span_log(&s->logging, SPAN_LOG_FLOW, "Switching from V.29 + V.21 to V.29 (%.2fdBm0)\n", v29_rx_signal_power(&(s->v29rx)));
+        s->rx_handler = (span_rx_handler_t *) &v29_rx;
+        s->rx_user_data = &(s->v29rx);
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+int fax_rx(fax_state_t *s, int16_t *amp, int len)
+{
+    int i;
+
+#if defined(LOG_FAX_AUDIO)
+    if (s->fax_audio_rx_log >= 0)
+        write(s->fax_audio_rx_log, amp, len*sizeof(int16_t));
+#endif
+    for (i = 0;  i < len;  i++)
+        amp[i] = dc_restore(&(s->dc_restore), amp[i]);
+    s->rx_handler(s->rx_user_data, amp, len);
+    t30_timer_update(&(s->t30_state), len);
+    return  0;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int set_next_tx_type(fax_state_t *s)
+{
+    if (s->next_tx_handler)
+    {
+        s->tx_handler = s->next_tx_handler;
+        s->tx_user_data = s->next_tx_user_data;
+        s->next_tx_handler = NULL;
+        return 0;
+    }
+    /* If there is nothing else to change to, so use zero length silence */
+    silence_gen_alter(&(s->silence_gen), 0);
+    s->tx_handler = (span_tx_handler_t *) &silence_gen;
+    s->tx_user_data = &(s->silence_gen);
+    s->next_tx_handler = NULL;
+    s->transmit = FALSE;
+    return -1;
+}
+/*- End of function --------------------------------------------------------*/
+
+int fax_tx(fax_state_t *s, int16_t *amp, int max_len)
+{
+    int len;
+#if defined(LOG_FAX_AUDIO)
+    int required_len;
+    
+    required_len = max_len;
+#endif
+    len = 0;
+    if (s->transmit)
+    {
+        while ((len += s->tx_handler(s->tx_user_data, amp + len, max_len - len)) < max_len)
+        {
+            /* Allow for a change of tx handler within a block */
+            if (set_next_tx_type(s)  &&  s->current_tx_type != T30_MODEM_NONE  &&  s->current_tx_type != T30_MODEM_DONE)
+                t30_send_complete(&(s->t30_state));
+            if (!s->transmit)
+            {
+                if (s->transmit_on_idle)
+                {
+                    /* Pad to the requested length with silence */
+                    memset(amp + len, 0, (max_len - len)*sizeof(int16_t));
+                    len = max_len;        
+                }
+                break;
+            }
+        }
+    }
+    else
+    {
+        if (s->transmit_on_idle)
+        {
+            /* Pad to the requested length with silence */
+            memset(amp, 0, max_len*sizeof(int16_t));
+            len = max_len;        
+        }
+    }
+#if defined(LOG_FAX_AUDIO)
+    if (s->fax_audio_tx_log >= 0)
+    {
+        if (len < required_len)
+            memset(amp + len, 0, (required_len - len)*sizeof(int16_t));
+        write(s->fax_audio_tx_log, amp, required_len*sizeof(int16_t));
+    }
+#endif
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void fax_set_rx_type(void *user_data, int type, int short_train, int use_hdlc)
+{
+    fax_state_t *s;
+    put_bit_func_t put_bit_func;
+    void *put_bit_user_data;
+
+    s = (fax_state_t *) user_data;
+    span_log(&s->logging, SPAN_LOG_FLOW, "Set rx type %d\n", type);
+    if (s->current_rx_type == type)
+        return;
+    s->current_rx_type = type;
+    if (use_hdlc)
+    {
+        put_bit_func = (put_bit_func_t) hdlc_rx_put_bit;
+        put_bit_user_data = (void *) &(s->hdlcrx);
+        hdlc_rx_init(&(s->hdlcrx), FALSE, FALSE, 5, t30_hdlc_accept, &(s->t30_state));
+    }
+    else
+    {
+        put_bit_func = t30_non_ecm_put_bit;
+        put_bit_user_data = (void *) &(s->t30_state);
+    }
+    switch (type)
+    {
+    case T30_MODEM_V21:
+        if (s->flush_handler)
+            s->flush_handler(s, s->flush_user_data, 3);
+        fsk_rx_init(&(s->v21rx), &preset_fsk_specs[FSK_V21CH2], TRUE, (put_bit_func_t) hdlc_rx_put_bit, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &fsk_rx;
+        s->rx_user_data = &(s->v21rx);
+        break;
+    case T30_MODEM_V27TER_2400:
+        v27ter_rx_restart(&(s->v27ter_rx), 2400, FALSE);
+        v27ter_rx_set_put_bit(&(s->v27ter_rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v27ter_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V27TER_4800:
+        v27ter_rx_restart(&(s->v27ter_rx), 4800, FALSE);
+        v27ter_rx_set_put_bit(&(s->v27ter_rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v27ter_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V29_7200:
+        v29_rx_restart(&(s->v29rx), 7200, FALSE);
+        v29_rx_set_put_bit(&(s->v29rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v29_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V29_9600:
+        v29_rx_restart(&(s->v29rx), 9600, FALSE);
+        v29_rx_set_put_bit(&(s->v29rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v29_rx;
+        s->rx_user_data = s;
+        break;
+#if defined(ENABLE_V17)
+    case T30_MODEM_V17_7200:
+        v17_rx_restart(&(s->v17rx), 7200, short_train);
+        v17_rx_set_put_bit(&(s->v17rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v17_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V17_9600:
+        v17_rx_restart(&(s->v17rx), 9600, short_train);
+        v17_rx_set_put_bit(&(s->v17rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v17_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V17_12000:
+        v17_rx_restart(&(s->v17rx), 12000, short_train);
+        v17_rx_set_put_bit(&(s->v17rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v17_rx;
+        s->rx_user_data = s;
+        break;
+    case T30_MODEM_V17_14400:
+        v17_rx_restart(&(s->v17rx), 14400, short_train);
+        v17_rx_set_put_bit(&(s->v17rx), put_bit_func, put_bit_user_data);
+        s->rx_handler = (span_rx_handler_t *) &early_v17_rx;
+        s->rx_user_data = s;
+        break;
+#endif
+    case T30_MODEM_DONE:
+        span_log(&s->logging, SPAN_LOG_FLOW, "FAX exchange complete\n");
+    default:
+        s->rx_handler = (span_rx_handler_t *) &dummy_rx;
+        s->rx_user_data = s;
+        break;
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static void fax_set_tx_type(void *user_data, int type, int short_train, int use_hdlc)
+{
+    fax_state_t *s;
+    tone_gen_descriptor_t tone_desc;
+    get_bit_func_t get_bit_func;
+    void *get_bit_user_data;
+
+    s = (fax_state_t *) user_data;
+    span_log(&s->logging, SPAN_LOG_FLOW, "Set tx type %d\n", type);
+    if (s->current_tx_type == type)
+        return;
+    s->first_tx_hdlc_frame = TRUE;
+    if (use_hdlc)
+    {
+        get_bit_func = (get_bit_func_t) hdlc_tx_get_bit;
+        get_bit_user_data = (void *) &(s->hdlctx);
+    }
+    else
+    {
+        get_bit_func = t30_non_ecm_get_bit;
+        get_bit_user_data = (void *) &(s->t30_state);
+    }
+    switch (type)
+    {
+    case T30_MODEM_PAUSE:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(short_train));
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = NULL;
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_CNG:
+        /* 0.5s of 1100Hz+-38Hz + 3.0s of silence repeating. Timing +-15% */
+        make_tone_gen_descriptor(&tone_desc,
+                                 1100,
+                                 -11,
+                                 0,
+                                 0,
+                                 500,
+                                 3000,
+                                 0,
+                                 0,
+                                 TRUE);
+        tone_gen_init(&(s->tone_gen), &tone_desc);
+        s->tx_handler = (span_tx_handler_t *) &tone_gen;
+        s->tx_user_data = &(s->tone_gen);
+        s->next_tx_handler = NULL;
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_CED:
+        /* 0.2s of silence, then 2.6s to 4s of 2100Hz+-15Hz tone, then 75ms of silence. The 75ms of silence
+           will be inserted by the pre V.21 pause we use for any switch to V.21. */
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(200));
+        make_tone_gen_descriptor(&tone_desc,
+                                 2100,
+                                 -11,
+                                 0,
+                                 0,
+                                 2600,
+                                 0,
+                                 0,
+                                 0,
+                                 FALSE);
+        tone_gen_init(&(s->tone_gen), &tone_desc);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &tone_gen;
+        s->next_tx_user_data = &(s->tone_gen);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V21:
+        fsk_tx_init(&(s->v21tx), &preset_fsk_specs[FSK_V21CH2], get_bit_func, get_bit_user_data);
+        /* The spec says 1s +-15% of preamble. So, the minimum is 32 octets. */
+        hdlc_tx_preamble(&(s->hdlctx), 32);
+        /* Pause before switching from phase C, as per T.30 5.3.2.2. If we omit this, the receiver
+           might not see the carrier fall between the high speed and low speed sections. In practice,
+           a 75ms gap before any V.21 transmission is harmless, adds little to the overall length of
+           a call, and ensures the receiving end is ready. */
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &fsk_tx;
+        s->next_tx_user_data = &(s->v21tx);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V27TER_2400:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v27ter_tx_restart(&(s->v27ter_tx), 2400, s->use_tep);
+        v27ter_tx_set_get_bit(&(s->v27ter_tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v27ter_tx;
+        s->next_tx_user_data = &(s->v27ter_tx);
+        hdlc_tx_preamble(&(s->hdlctx), 60);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V27TER_4800:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v27ter_tx_restart(&(s->v27ter_tx), 4800, s->use_tep);
+        v27ter_tx_set_get_bit(&(s->v27ter_tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v27ter_tx;
+        s->next_tx_user_data = &(s->v27ter_tx);
+        hdlc_tx_preamble(&(s->hdlctx), 120);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V29_7200:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v29_tx_restart(&(s->v29tx), 7200, s->use_tep);
+        v29_tx_set_get_bit(&(s->v29tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v29_tx;
+        s->next_tx_user_data = &(s->v29tx);
+        hdlc_tx_preamble(&(s->hdlctx), 180);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V29_9600:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v29_tx_restart(&(s->v29tx), 9600, s->use_tep);
+        v29_tx_set_get_bit(&(s->v29tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v29_tx;
+        s->next_tx_user_data = &(s->v29tx);
+        hdlc_tx_preamble(&(s->hdlctx), 240);
+        s->transmit = TRUE;
+        break;
+#if defined(ENABLE_V17)
+    case T30_MODEM_V17_7200:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v17_tx_restart(&(s->v17tx), 7200, s->use_tep, short_train);
+        v17_tx_set_get_bit(&(s->v17tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v17_tx;
+        s->next_tx_user_data = &(s->v17tx);
+        hdlc_tx_preamble(&(s->hdlctx), 180);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V17_9600:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v17_tx_restart(&(s->v17tx), 9600, s->use_tep, short_train);
+        v17_tx_set_get_bit(&(s->v17tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v17_tx;
+        s->next_tx_user_data = &(s->v17tx);
+        hdlc_tx_preamble(&(s->hdlctx), 240);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V17_12000:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v17_tx_restart(&(s->v17tx), 12000, s->use_tep, short_train);
+        v17_tx_set_get_bit(&(s->v17tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v17_tx;
+        s->next_tx_user_data = &(s->v17tx);
+        hdlc_tx_preamble(&(s->hdlctx), 300);
+        s->transmit = TRUE;
+        break;
+    case T30_MODEM_V17_14400:
+        silence_gen_alter(&(s->silence_gen), ms_to_samples(75));
+        v17_tx_restart(&(s->v17tx), 14400, s->use_tep, short_train);
+        v17_tx_set_get_bit(&(s->v17tx), get_bit_func, get_bit_user_data);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = (span_tx_handler_t *) &v17_tx;
+        s->next_tx_user_data = &(s->v17tx);
+        hdlc_tx_preamble(&(s->hdlctx), 360);
+        s->transmit = TRUE;
+        break;
+#endif
+    case T30_MODEM_DONE:
+        span_log(&s->logging, SPAN_LOG_FLOW, "FAX exchange complete\n");
+        /* Fall through */
+    default:
+        silence_gen_alter(&(s->silence_gen), 0);
+        s->tx_handler = (span_tx_handler_t *) &silence_gen;
+        s->tx_user_data = &(s->silence_gen);
+        s->next_tx_handler = NULL;
+        s->transmit = FALSE;
+        break;
+    }
+    s->current_tx_type = type;
+}
+/*- End of function --------------------------------------------------------*/
+
+void fax_set_transmit_on_idle(fax_state_t *s, int transmit_on_idle)
+{
+    s->transmit_on_idle = transmit_on_idle;
+}
+/*- End of function --------------------------------------------------------*/
+
+void fax_set_tep_mode(fax_state_t *s, int use_tep)
+{
+    s->use_tep = use_tep;
+}
+/*- End of function --------------------------------------------------------*/
+
+int fax_init(fax_state_t *s, int calling_party)
+{
+    memset(s, 0, sizeof(*s));
+    span_log_init(&s->logging, SPAN_LOG_NONE, NULL);
+    span_log_set_protocol(&s->logging, "FAX");
+    t30_init(&(s->t30_state),
+             calling_party,
+             fax_set_rx_type,
+             (void *) s,
+             fax_set_tx_type,
+             (void *) s,
+             fax_send_hdlc,
+             (void *) s);
+    t30_set_supported_modems(&(s->t30_state),
+#if defined(ENABLE_V17)
+                             T30_SUPPORT_V27TER | T30_SUPPORT_V29 | T30_SUPPORT_V17);
+#else    
+                             T30_SUPPORT_V27TER | T30_SUPPORT_V29);
+#endif
+    hdlc_rx_init(&(s->hdlcrx), FALSE, FALSE, 5, t30_hdlc_accept, &(s->t30_state));
+    fsk_rx_init(&(s->v21rx), &preset_fsk_specs[FSK_V21CH2], TRUE, (put_bit_func_t) hdlc_rx_put_bit, &(s->hdlcrx));
+    hdlc_tx_init(&(s->hdlctx), FALSE, 2, FALSE, t30_send_complete, &(s->t30_state));
+    s->first_tx_hdlc_frame = TRUE;
+    fsk_tx_init(&(s->v21tx), &preset_fsk_specs[FSK_V21CH2], (get_bit_func_t) hdlc_tx_get_bit, &(s->hdlctx));
+#if defined(ENABLE_V17)
+    v17_rx_init(&(s->v17rx), 14400, t30_non_ecm_put_bit, &(s->t30_state));
+    v17_tx_init(&(s->v17tx), 14400, s->use_tep, t30_non_ecm_get_bit, &(s->t30_state));
+#endif
+    v29_rx_init(&(s->v29rx), 9600, t30_non_ecm_put_bit, &(s->t30_state));
+    v29_rx_signal_cutoff(&(s->v29rx), -45.5);
+    v29_tx_init(&(s->v29tx), 9600, s->use_tep, t30_non_ecm_get_bit, &(s->t30_state));
+    v27ter_rx_init(&(s->v27ter_rx), 4800, t30_non_ecm_put_bit, &(s->t30_state));
+    v27ter_tx_init(&(s->v27ter_tx), 4800, s->use_tep, t30_non_ecm_get_bit, &(s->t30_state));
+    silence_gen_init(&(s->silence_gen), 0);
+    dc_restore_init(&(s->dc_restore));
+    t30_restart(&(s->t30_state));
+#if defined(LOG_FAX_AUDIO)
+    {
+        char buf[100 + 1];
+        struct tm *tm;
+        time_t now;
+
+        time(&now);
+        tm = localtime(&now);
+        sprintf(buf,
+                "/tmp/fax-rx-audio-%x-%02d%02d%02d%02d%02d%02d",
+                s,
+                tm->tm_year%100,
+                tm->tm_mon + 1,
+                tm->tm_mday,
+                tm->tm_hour,
+                tm->tm_min,
+                tm->tm_sec);
+        s->fax_audio_rx_log = open(buf, O_CREAT | O_TRUNC | O_WRONLY, 0666);
+        sprintf(buf,
+                "/tmp/fax-tx-audio-%x-%02d%02d%02d%02d%02d%02d",
+                s,
+                tm->tm_year%100,
+                tm->tm_mon + 1,
+                tm->tm_mday,
+                tm->tm_hour,
+                tm->tm_min,
+                tm->tm_sec);
+        s->fax_audio_tx_log = open(buf, O_CREAT | O_TRUNC | O_WRONLY, 0666);
+    }
+#endif
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+int fax_release(fax_state_t *s)
+{
+    t30_release(&s->t30_state);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+void fax_set_flush_handler(fax_state_t *s, fax_flush_handler_t *handler, void *user_data)
+{
+    s->flush_handler = handler;
+    s->flush_user_data = user_data;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/