--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/tests/fax_decode.c	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,535 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * fax_decode.c - a simple FAX audio decoder
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2005 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_decode.c,v 1.58 2009/11/02 13:25:20 steveu Exp $
+ */
+
+/*! \page fax_decode_page FAX decoder
+\section fax_decode_page_sec_1 What does it do?
+???.
+
+\section fax_decode_tests_page_sec_2 How does it work?
+???.
+*/
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <sndfile.h>
+
+//#if defined(WITH_SPANDSP_INTERNALS)
+#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
+//#endif
+
+#include "spandsp.h"
+
+#define SAMPLES_PER_CHUNK   160
+
+#define DISBIT1     0x01
+#define DISBIT2     0x02
+#define DISBIT3     0x04
+#define DISBIT4     0x08
+#define DISBIT5     0x10
+#define DISBIT6     0x20
+#define DISBIT7     0x40
+#define DISBIT8     0x80
+
+enum
+{
+    FAX_NONE,
+    FAX_V27TER_RX,
+    FAX_V29_RX,
+    FAX_V17_RX
+};
+
+static const struct
+{
+    int bit_rate;
+    int modem_type;
+    int which;
+    uint8_t dcs_code;
+} fallback_sequence[] =
+{
+    {14400, T30_MODEM_V17,    T30_SUPPORT_V17,    DISBIT6},
+    {12000, T30_MODEM_V17,    T30_SUPPORT_V17,    (DISBIT6 | DISBIT4)},
+    { 9600, T30_MODEM_V17,    T30_SUPPORT_V17,    (DISBIT6 | DISBIT3)},
+    { 9600, T30_MODEM_V29,    T30_SUPPORT_V29,    DISBIT3},
+    { 7200, T30_MODEM_V17,    T30_SUPPORT_V17,    (DISBIT6 | DISBIT4 | DISBIT3)},
+    { 7200, T30_MODEM_V29,    T30_SUPPORT_V29,    (DISBIT4 | DISBIT3)},
+    { 4800, T30_MODEM_V27TER, T30_SUPPORT_V27TER, DISBIT4},
+    { 2400, T30_MODEM_V27TER, T30_SUPPORT_V27TER, 0},
+    {    0, 0, 0, 0}
+};
+
+int decode_test = FALSE;
+int rx_bits = 0;
+
+t30_state_t t30_dummy;
+t4_state_t t4_state;
+int t4_up = FALSE;
+
+hdlc_rx_state_t hdlcrx;
+
+int fast_trained = FAX_NONE;
+
+uint8_t ecm_data[256][260];
+int16_t ecm_len[256];
+
+int line_encoding = T4_COMPRESSION_ITU_T4_1D;
+int x_resolution = T4_X_RESOLUTION_R8;
+int y_resolution = T4_Y_RESOLUTION_STANDARD;
+int image_width = 1728;
+int octets_per_ecm_frame = 256;
+int error_correcting_mode = FALSE;
+int current_fallback = 0;
+
+static void print_frame(const char *io, const uint8_t *fr, int frlen)
+{
+    int i;
+    int type;
+    const char *country;
+    const char *vendor;
+    const char *model;
+    
+    fprintf(stderr, "%s %s:", io, t30_frametype(fr[2]));
+    for (i = 2;  i < frlen;  i++)
+        fprintf(stderr, " %02x", fr[i]);
+    fprintf(stderr, "\n");
+    type = fr[2] & 0xFE;
+    if (type == T30_DIS  ||  type == T30_DTC  ||  type == T30_DCS)
+        t30_decode_dis_dtc_dcs(&t30_dummy, fr, frlen);
+    if (type == T30_NSF  ||  type == T30_NSS  ||  type == T30_NSC)
+    {
+        if (t35_decode(&fr[3], frlen - 3, &country, &vendor, &model))
+        {
+            if (country)
+                fprintf(stderr, "The remote was made in '%s'\n", country);
+            if (vendor)
+                fprintf(stderr, "The remote was made by '%s'\n", vendor);
+            if (model)
+                fprintf(stderr, "The remote is a '%s'\n", model);
+        }
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static int find_fallback_entry(int dcs_code)
+{
+    int i;
+
+    /* The table is short, and not searched often, so a brain-dead linear scan seems OK */
+    for (i = 0;  fallback_sequence[i].bit_rate;  i++)
+    {
+        if (fallback_sequence[i].dcs_code == dcs_code)
+            break;
+    }
+    if (fallback_sequence[i].bit_rate == 0)
+        return -1;
+    return i;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int check_rx_dcs(const uint8_t *msg, int len)
+{
+    static const int widths[3][4] =
+    {
+        { 864, 1024, 1216, -1}, /* R4 resolution - no longer used in recent versions of T.30 */
+        {1728, 2048, 2432, -1}, /* R8 resolution */
+        {3456, 4096, 4864, -1}  /* R16 resolution */
+    };
+    uint8_t dcs_frame[T30_MAX_DIS_DTC_DCS_LEN];
+
+    /* Check DCS frame from remote */
+    if (len < 6)
+    {
+        printf("Short DCS frame\n");
+        return -1;
+    }
+
+    /* Make a local copy of the message, padded to the maximum possible length with zeros. This allows
+       us to simply pick out the bits, without worrying about whether they were set from the remote side. */
+    if (len > T30_MAX_DIS_DTC_DCS_LEN)
+    {
+        memcpy(dcs_frame, msg, T30_MAX_DIS_DTC_DCS_LEN);
+    }
+    else
+    {
+        memcpy(dcs_frame, msg, len);
+        if (len < T30_MAX_DIS_DTC_DCS_LEN)
+            memset(dcs_frame + len, 0, T30_MAX_DIS_DTC_DCS_LEN - len);
+    }
+
+    octets_per_ecm_frame = (dcs_frame[6] & DISBIT4)  ?  256  :  64;
+    if ((dcs_frame[8] & DISBIT1))
+        y_resolution = T4_Y_RESOLUTION_SUPERFINE;
+    else if (dcs_frame[4] & DISBIT7)
+        y_resolution = T4_Y_RESOLUTION_FINE;
+    else
+        y_resolution = T4_Y_RESOLUTION_STANDARD;
+    image_width = widths[(dcs_frame[8] & DISBIT3)  ?  2  :  1][dcs_frame[5] & (DISBIT2 | DISBIT1)];
+
+    /* Check which compression we will use. */
+    if ((dcs_frame[6] & DISBIT7))
+        line_encoding = T4_COMPRESSION_ITU_T6;
+    else if ((dcs_frame[4] & DISBIT8))
+        line_encoding = T4_COMPRESSION_ITU_T4_2D;
+    else
+        line_encoding = T4_COMPRESSION_ITU_T4_1D;
+    fprintf(stderr, "Selected compression %d\n", line_encoding);
+
+    if ((current_fallback = find_fallback_entry(dcs_frame[4] & (DISBIT6 | DISBIT5 | DISBIT4 | DISBIT3))) < 0)
+        printf("Remote asked for a modem standard we do not support\n");
+    error_correcting_mode = ((dcs_frame[6] & DISBIT3) != 0);
+
+    //v17_rx_restart(&v17, fallback_sequence[fallback_entry].bit_rate, FALSE);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok)
+{
+    int type;
+    int frame_no;
+    int i;
+
+    if (len < 0)
+    {
+        /* Special conditions */
+        fprintf(stderr, "HDLC status is %s (%d)\n", signal_status_to_str(len), len);
+        return;
+    }
+
+    if (ok)
+    {
+        if (msg[0] != 0xFF  ||  !(msg[1] == 0x03  ||  msg[1] == 0x13))
+        {
+            fprintf(stderr, "Bad frame header - %02x %02x\n", msg[0], msg[1]);
+            return;
+        }
+        print_frame("HDLC: ", msg, len);
+        type = msg[2] & 0xFE;
+        switch (type)
+        {
+        case T4_FCD:
+            if (len <= 4 + 256)
+            {
+                frame_no = msg[3];
+                /* Just store the actual image data, and record its length */
+                memcpy(&ecm_data[frame_no][0], &msg[4], len - 4);
+                ecm_len[frame_no] = (int16_t) (len - 4);
+            }
+            break;
+        case T30_DCS:
+            check_rx_dcs(msg, len);
+            break;
+        }
+    }
+    else
+    {
+        fprintf(stderr, "Bad HDLC frame ");
+        for (i = 0;  i < len;  i++)
+            fprintf(stderr, " %02x", msg[i]);
+        fprintf(stderr, "\n");
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+static void t4_begin(void)
+{
+    int i;
+
+    //printf("Begin T.4 - %d %d %d %d\n", line_encoding, x_resolution, y_resolution, image_width);
+    t4_rx_set_rx_encoding(&t4_state, line_encoding);
+    t4_rx_set_x_resolution(&t4_state, x_resolution);
+    t4_rx_set_y_resolution(&t4_state, y_resolution);
+    t4_rx_set_image_width(&t4_state, image_width);
+
+    t4_rx_start_page(&t4_state);
+    t4_up = TRUE;
+
+    for (i = 0;  i < 256;  i++)
+        ecm_len[i] = -1;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void t4_end(void)
+{
+    t4_stats_t stats;
+    int i;
+    int j;
+    int k;
+
+    if (!t4_up)
+        return;
+    if (error_correcting_mode)
+    {
+        for (i = 0;  i < 256;  i++)
+        {
+            for (j = 0;  j < ecm_len[i];  j++)
+            {
+                for (k = 0;  k < 8;  k++)
+                    t4_rx_put_bit(&t4_state, (ecm_data[i][j] >> k) & 1);
+            }
+            fprintf(stderr, "%d", (ecm_len[i] < 0)  ?  0  :  1);
+        }
+        fprintf(stderr, "\n");
+    }
+    t4_rx_end_page(&t4_state);
+    t4_get_transfer_statistics(&t4_state, &stats);
+    fprintf(stderr, "Pages = %d\n", stats.pages_transferred);
+    fprintf(stderr, "Image size = %dx%d\n", stats.width, stats.length);
+    fprintf(stderr, "Image resolution = %dx%d\n", stats.x_resolution, stats.y_resolution);
+    fprintf(stderr, "Bad rows = %d\n", stats.bad_rows);
+    fprintf(stderr, "Longest bad row run = %d\n", stats.longest_bad_row_run);
+    t4_up = FALSE;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v21_put_bit(void *user_data, int bit)
+{
+    if (bit < 0)
+    {
+        /* Special conditions */
+        fprintf(stderr, "V.21 rx status is %s (%d)\n", signal_status_to_str(bit), bit);
+        switch (bit)
+        {
+        case SIG_STATUS_CARRIER_DOWN:
+            //t4_end();
+            break;
+        }
+        return;
+    }
+    if (fast_trained == FAX_NONE)
+        hdlc_rx_put_bit(&hdlcrx, bit);
+    //printf("V.21 Rx bit %d - %d\n", rx_bits++, bit);
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v17_put_bit(void *user_data, int bit)
+{
+    if (bit < 0)
+    {
+        /* Special conditions */
+        fprintf(stderr, "V.17 rx status is %s (%d)\n", signal_status_to_str(bit), bit);
+        switch (bit)
+        {
+        case SIG_STATUS_TRAINING_SUCCEEDED:
+            fast_trained = FAX_V17_RX;
+            t4_begin();
+            break;
+        case SIG_STATUS_CARRIER_DOWN:
+            t4_end();
+            if (fast_trained == FAX_V17_RX)
+                fast_trained = FAX_NONE;
+            break;
+        }
+        return;
+    }
+    if (error_correcting_mode)
+    {
+        hdlc_rx_put_bit(&hdlcrx, bit);
+    }
+    else
+    {
+        if (t4_rx_put_bit(&t4_state, bit))
+        {
+            t4_end();
+            fprintf(stderr, "End of page detected\n");
+        }
+    }
+    //printf("V.17 Rx bit %d - %d\n", rx_bits++, bit);
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v29_put_bit(void *user_data, int bit)
+{
+    if (bit < 0)
+    {
+        /* Special conditions */
+        fprintf(stderr, "V.29 rx status is %s (%d)\n", signal_status_to_str(bit), bit);
+        switch (bit)
+        {
+        case SIG_STATUS_TRAINING_SUCCEEDED:
+            fast_trained = FAX_V29_RX;
+            t4_begin();
+            break;
+        case SIG_STATUS_CARRIER_DOWN:
+            t4_end();
+            if (fast_trained == FAX_V29_RX)
+                fast_trained = FAX_NONE;
+            break;
+        }
+        return;
+    }
+    if (error_correcting_mode)
+    {
+        hdlc_rx_put_bit(&hdlcrx, bit);
+    }
+    else
+    {
+        if (t4_rx_put_bit(&t4_state, bit))
+        {
+            t4_end();
+            fprintf(stderr, "End of page detected\n");
+        }
+    }
+    //printf("V.29 Rx bit %d - %d\n", rx_bits++, bit);
+}
+/*- End of function --------------------------------------------------------*/
+
+static void v27ter_put_bit(void *user_data, int bit)
+{
+    if (bit < 0)
+    {
+        /* Special conditions */
+        fprintf(stderr, "V.27ter rx status is %s (%d)\n", signal_status_to_str(bit), bit);
+        switch (bit)
+        {
+        case SIG_STATUS_TRAINING_SUCCEEDED:
+            fast_trained = FAX_V27TER_RX;
+            t4_begin();
+            break;
+        case SIG_STATUS_CARRIER_DOWN:
+            t4_end();
+            if (fast_trained == FAX_V27TER_RX)
+                fast_trained = FAX_NONE;
+            break;
+        }
+        return;
+    }
+    if (error_correcting_mode)
+    {
+        hdlc_rx_put_bit(&hdlcrx, bit);
+    }
+    else
+    {
+        if (t4_rx_put_bit(&t4_state, bit))
+        {
+            t4_end();
+            fprintf(stderr, "End of page detected\n");
+        }
+    }
+    //printf("V.27ter Rx bit %d - %d\n", rx_bits++, bit);
+}
+/*- End of function --------------------------------------------------------*/
+
+int main(int argc, char *argv[])
+{
+    fsk_rx_state_t *fsk;
+    v17_rx_state_t *v17;
+    v29_rx_state_t *v29;
+    v27ter_rx_state_t *v27ter;
+    int16_t amp[SAMPLES_PER_CHUNK];
+    SNDFILE *inhandle;
+    SF_INFO info;
+    int len;
+    const char *filename;
+    logging_state_t *logging;
+
+    filename = "fax_samp.wav";
+
+    if (argc > 1)
+        filename = argv[1];
+
+    memset(&info, 0, sizeof(info));
+    if ((inhandle = sf_open(filename, SFM_READ, &info)) == NULL)
+    {
+        fprintf(stderr, "    Cannot open audio file '%s' for reading\n", filename);
+        exit(2);
+    }
+    if (info.samplerate != SAMPLE_RATE)
+    {
+        printf("    Unexpected sample rate in audio file '%s'\n", filename);
+        exit(2);
+    }
+    if (info.channels != 1)
+    {
+        printf("    Unexpected number of channels in audio file '%s'\n", filename);
+        exit(2);
+    }
+
+    memset(&t30_dummy, 0, sizeof(t30_dummy));
+    span_log_init(&t30_dummy.logging, SPAN_LOG_FLOW, NULL);
+    span_log_set_protocol(&t30_dummy.logging, "T.30");
+
+    hdlc_rx_init(&hdlcrx, FALSE, TRUE, 5, hdlc_accept, NULL);
+    fsk = fsk_rx_init(NULL, &preset_fsk_specs[FSK_V21CH2], FSK_FRAME_MODE_SYNC, v21_put_bit, NULL);
+    v17 = v17_rx_init(NULL, 14400, v17_put_bit, NULL);
+    v29 = v29_rx_init(NULL, 9600, v29_put_bit, NULL);
+    //v29 = v29_rx_init(NULL, 7200, v29_put_bit, NULL);
+    v27ter = v27ter_rx_init(NULL, 4800, v27ter_put_bit, NULL);
+    fsk_rx_signal_cutoff(fsk, -45.5);
+    v17_rx_signal_cutoff(v17, -45.5);
+    v29_rx_signal_cutoff(v29, -45.5);
+    v27ter_rx_signal_cutoff(v27ter, -40.0);
+
+#if 1
+    logging = v17_rx_get_logging_state(v17);
+    span_log_init(logging, SPAN_LOG_FLOW, NULL);
+    span_log_set_protocol(logging, "V.17");
+    span_log_set_level(logging, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | SPAN_LOG_SHOW_TAG | SPAN_LOG_FLOW);
+
+    logging = v29_rx_get_logging_state(v29);
+    span_log_init(logging, SPAN_LOG_FLOW, NULL);
+    span_log_set_protocol(logging, "V.29");
+    span_log_set_level(logging, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | SPAN_LOG_SHOW_TAG | SPAN_LOG_FLOW);
+
+    logging = v27ter_rx_get_logging_state(v27ter);
+    span_log_init(logging, SPAN_LOG_FLOW, NULL);
+    span_log_set_protocol(logging, "V.27ter");
+    span_log_set_level(logging, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | SPAN_LOG_SHOW_TAG | SPAN_LOG_FLOW);
+#endif
+
+    if (t4_rx_init(&t4_state, "fax_decode.tif", T4_COMPRESSION_ITU_T4_2D) == NULL)
+    {
+        fprintf(stderr, "Failed to init\n");
+        exit(0);
+    }
+        
+    for (;;)
+    {
+        len = sf_readf_short(inhandle, amp, SAMPLES_PER_CHUNK);
+        if (len < SAMPLES_PER_CHUNK)
+            break;
+        fsk_rx(fsk, amp, len);
+        v17_rx(v17, amp, len);
+        v29_rx(v29, amp, len);
+        //v27ter_rx(v27ter, amp, len);
+    }
+    t4_rx_release(&t4_state);
+
+    if (sf_close(inhandle) != 0)
+    {
+        fprintf(stderr, "    Cannot close audio file '%s'\n", filename);
+        exit(2);
+    }
+    return  0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/