--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/tests/ip_network_model.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,149 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * ip_network_model.c - Model an IP networks latency, jitter and loss.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 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: ip_network_model.c,v 1.4 2006/11/19 14:07:27 steveu Exp $
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <string.h>
+#include <time.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <audiofile.h>
+#include <tiffio.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#define GEN_CONST
+#include <math.h>
+#endif
+
+#include "spandsp.h"
+
+#include "ip_network_model.h"
+
+#if !defined(NULL)
+#define NULL (void *) 0
+#endif
+
+void ip_network_model_send(ip_network_model_state_t *s,
+                            int seq_no,
+                            int count,
+                            const uint8_t *buf,
+                            int len)
+{
+    int delay[2];
+    int i;
+
+    for (i = 0;  i < count;  i++)
+    {
+        if (rand()%1000000 >= s->packet_loss)
+        {
+            delay[0] = s->current_samples + s->bulk_delay + (rand()%s->jitter);
+            delay[1] = seq_no;
+            queue_write_msg(&s->packet_queue, (uint8_t *) delay, sizeof(delay));
+            queue_write_msg(&s->packet_queue, buf, len);
+        }
+        else
+        {
+            fprintf(stderr, "Dropping packet - seq %d\n", seq_no);
+        }
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+int ip_network_model_get(ip_network_model_state_t *s,
+                          int time_step,
+                          uint8_t *msg,
+                          int max_len,
+                          int *seq_no)
+{
+    int len;
+
+    s->current_samples += time_step;
+
+    if (s->delay[0] < 0)
+    {
+        /* Wait for a new packet */
+        if (queue_empty(&s->packet_queue))
+            return -1;
+        len = queue_read_msg(&s->packet_queue, (uint8_t *) s->delay, sizeof(s->delay));
+        if (len != sizeof(s->delay))
+            return -1;
+    }
+    *seq_no = s->delay[1];
+    /* Wait for the appropriate time */
+    if (s->delay[0] > s->current_samples)
+        return -1;
+    /* Wait for a message */
+    if (queue_empty(&s->packet_queue))
+        return -1;
+    s->delay[0] = -1;
+    s->delay[1] = -1;
+    len = queue_read_msg(&s->packet_queue, msg, max_len);
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+ip_network_model_state_t *ip_network_model_init(int bulk_delay,
+                                                int jitter,
+                                                int loss)
+{
+    ip_network_model_state_t *s;
+
+    if ((s = (ip_network_model_state_t *) malloc(sizeof(*s))) == NULL)
+        return NULL;
+    memset(s, 0, sizeof(*s));
+
+    s->bulk_delay = bulk_delay;
+    s->jitter = jitter;
+    s->packet_loss = loss;
+
+    s->delay[0] = -1;
+    s->delay[1] = -1;
+    
+    if (queue_create(&s->packet_queue, 32768, QUEUE_WRITE_ATOMIC | QUEUE_READ_ATOMIC) < 0)
+    {
+        free(s);
+        return NULL;
+    }
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+
+int ip_network_model_release(ip_network_model_state_t *s)
+{
+    queue_delete(&s->packet_queue);
+    free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/