diff --git a/pjsip-apps/src/samples/sndtest.c b/pjsip-apps/src/samples/sndtest.c
new file mode 100644
index 0000000..6b518e2
--- /dev/null
+++ b/pjsip-apps/src/samples/sndtest.c
@@ -0,0 +1,540 @@
+/* $Id$ */
+/* 
+ * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+
+#include <pjmedia.h>
+#include <pjlib.h>
+#include <pjlib-util.h>
+
+#include <stdlib.h>	/* atoi() */
+#include <stdio.h>
+
+
+
+#define THIS_FILE	    "sndtest.c"
+
+/* Warn (print log with yellow color) if frame jitter is larger than
+ * this value (in usec).
+ */
+#define WARN_JITTER_USEC    1000
+
+/* Test duration in msec */
+#define DURATION	    10000
+
+/* Max frames per sec. */
+#define MAX_FRAMES_PER_SEC  100
+
+/* Number of frame durations to keep */
+#define MAX_DELAY_COUNTER   (((DURATION/1000)+1)*MAX_FRAMES_PER_SEC)
+
+
+struct stream_data
+{
+    pj_uint32_t	    first_timestamp;
+    pj_uint32_t	    last_timestamp;
+    pj_timestamp    last_called;
+    unsigned	    counter;
+    unsigned	    min_delay;
+    unsigned	    max_delay;
+    unsigned	    delay[MAX_DELAY_COUNTER];
+};
+
+struct test_data {
+    pjmedia_dir dir;
+    unsigned clock_rate;
+    unsigned samples_per_frame;
+    unsigned channel_count;
+    pj_bool_t running;
+    pj_bool_t has_error;
+
+    struct stream_data capture_data;
+    struct stream_data playback_data;
+};
+
+
+
+static const char *desc = 
+ " sndtest.c						\n"
+ "							\n"
+ " PURPOSE:						\n"
+ "  Test the performance of sound device.		\n"
+ "							\n"
+ " USAGE:						\n"
+ "  sndtest --help					\n"
+ "  sndtest [options]					\n"
+ "							\n"
+ " where options:					\n"
+ "  --id=ID          -i  Use device ID (default is -1)	\n"
+ "  --rate=HZ        -r  Set test clock rate (default=8000)\n"
+ "  --frame=SAMPLES  -f  Set number of samples per frame\n"
+ "  --channel=CH     -n  Set number of channels (default=1)\n"
+ "  --verbose        -v  Show verbose result		\n"
+ "  --help           -h  Show this screen		\n"
+;
+
+
+
+static void enum_devices(void)
+{
+    int i, count;
+    
+    count = pjmedia_snd_get_dev_count();
+    if (count == 0) {
+	PJ_LOG(3,(THIS_FILE, "No devices found"));
+	return;
+    }
+
+    PJ_LOG(3,(THIS_FILE, "Found %d devices:", count));
+    for (i=0; i<count; ++i) {
+	const pjmedia_snd_dev_info *info;
+
+	info = pjmedia_snd_get_dev_info(i);
+	pj_assert(info != NULL);
+
+	PJ_LOG(3,(THIS_FILE," %d: %s (capture=%d, playback=%d)",
+	          i, info->name, info->input_count, info->output_count));
+    }
+}
+
+
+static const char *get_dev_name(int dev_id)
+{
+    const pjmedia_snd_dev_info *info;
+
+    if (dev_id == -1)
+	dev_id = 0;
+
+    info = pjmedia_snd_get_dev_info(dev_id);
+    if (info == NULL)
+	return "????";
+
+    return info->name;
+}
+
+
+static pj_status_t play_cb(void *user_data, pj_uint32_t timestamp,
+			   void *output, unsigned size)
+{
+    struct test_data *test_data = user_data;
+    struct stream_data *strm_data = &test_data->playback_data;
+
+    if (!test_data->running) {
+	pj_memset(output, 0, size);
+	return PJ_SUCCESS;
+    }
+
+    strm_data->last_timestamp = timestamp;
+
+    if (strm_data->last_called.u64 == 0) {
+	pj_get_timestamp(&strm_data->last_called);
+	strm_data->min_delay = test_data->samples_per_frame * 1000000 /
+			       test_data->clock_rate;
+	strm_data->first_timestamp = timestamp;
+
+    } else if (strm_data->counter <= MAX_DELAY_COUNTER) {
+	pj_timestamp now;
+	unsigned delay;
+
+	pj_get_timestamp(&now);
+	
+	delay = pj_elapsed_usec(&strm_data->last_called, &now);
+	if (delay < strm_data->min_delay)
+	    strm_data->min_delay = delay;
+	if (delay > strm_data->max_delay)
+	    strm_data->max_delay = delay;
+
+	strm_data->last_called = now;
+
+	strm_data->delay[strm_data->counter] = delay;
+	++strm_data->counter;
+    }
+
+    pj_memset(output, 0, size);
+    return PJ_SUCCESS;
+}
+
+static pj_status_t rec_cb(void *user_data, pj_uint32_t timestamp,
+			  const void *input, unsigned size)
+{
+
+    struct test_data *test_data = user_data;
+    struct stream_data *strm_data = &test_data->capture_data;
+
+    PJ_UNUSED_ARG(input);
+    PJ_UNUSED_ARG(size);
+
+    if (!test_data->running) {
+	return PJ_SUCCESS;
+    }
+
+    strm_data->last_timestamp = timestamp;
+
+    if (strm_data->last_called.u64 == 0) {
+	pj_get_timestamp(&strm_data->last_called);
+	strm_data->min_delay = test_data->samples_per_frame * 1000000 /
+			       test_data->clock_rate;
+	strm_data->first_timestamp = timestamp;
+
+    } else if (strm_data->counter <= MAX_DELAY_COUNTER) {
+	pj_timestamp now;
+	unsigned delay;
+
+	pj_get_timestamp(&now);
+	
+	delay = pj_elapsed_usec(&strm_data->last_called, &now);
+	if (delay < strm_data->min_delay)
+	    strm_data->min_delay = delay;
+	if (delay > strm_data->max_delay)
+	    strm_data->max_delay = delay;
+
+	strm_data->last_called = now;
+
+	strm_data->delay[strm_data->counter] = delay;
+	++strm_data->counter;
+    }
+
+    return PJ_SUCCESS;
+}
+
+static void app_perror(const char *title, pj_status_t status)
+{
+    char errmsg[PJ_ERR_MSG_SIZE];
+
+    pj_strerror(status, errmsg, sizeof(errmsg));	
+    printf( "%s: %s (err=%d)\n",
+	    title, errmsg, status);
+}
+
+
+static void print_stream_data(const char *title, 
+			      struct test_data *test_data,
+			      struct stream_data *strm_data,
+			      int verbose)
+{
+    unsigned i, dur;
+    unsigned min_jitter, max_jitter, avg_jitter=0;
+
+    PJ_LOG(3,(THIS_FILE, "  %s stream report:", title));
+
+    /* Check that frames are captured/played */
+    if (strm_data->counter == 0) {
+	PJ_LOG(1,(THIS_FILE, "   Error: no frames are captured/played!"));
+	test_data->has_error = 1;
+	return;
+    }
+
+    /* Duration */
+    dur = (strm_data->counter+1) * test_data->samples_per_frame * 1000 /
+		test_data->clock_rate;
+    PJ_LOG(3,(THIS_FILE, "   Duration: %ds.%03d",
+	      dur/1000, dur%1000));
+
+    /* Frame interval */
+    if (strm_data->max_delay - strm_data->min_delay < WARN_JITTER_USEC) {
+	PJ_LOG(3,(THIS_FILE, 
+		  "   Frame interval: min=%d.%03dms, max=%d.%03dms",
+		  strm_data->min_delay/1000, strm_data->min_delay%1000,
+		  strm_data->max_delay/1000, strm_data->max_delay%1000));
+    } else {
+	test_data->has_error = 1;
+	PJ_LOG(2,(THIS_FILE, 
+		  "   Frame interval: min=%d.%03dms, max=%d.%03dms",
+		  strm_data->min_delay/1000, strm_data->min_delay%1000,
+		  strm_data->max_delay/1000, strm_data->max_delay%1000));
+    }
+
+    if (verbose) {
+	unsigned i;
+	unsigned decor = pj_log_get_decor();
+
+	PJ_LOG(3,(THIS_FILE, "    Dumping frame delays:"));
+
+	pj_log_set_decor(0);
+	for (i=0; i<strm_data->counter; ++i)
+	    PJ_LOG(3,(THIS_FILE, " %d.%03d", strm_data->delay[i]/1000, 
+		      strm_data->delay[i]%1000));
+	PJ_LOG(3,(THIS_FILE, "\r\n"));
+	pj_log_set_decor(decor);
+    }
+
+    /* Calculate jitter */
+    min_jitter = 0xFFFFF;
+    max_jitter = 0;
+
+    for (i=1; i<strm_data->counter; ++i) {
+	int jitter;
+	jitter = strm_data->delay[i] - strm_data->delay[i-1];
+	if (jitter < 0) jitter = -jitter;
+	
+	if (jitter < (int)min_jitter) min_jitter = jitter;
+	if (jitter > (int)max_jitter) max_jitter = jitter;
+
+	avg_jitter = ((i-1) * avg_jitter + jitter) / i;
+    }
+    if (max_jitter < WARN_JITTER_USEC) {
+	PJ_LOG(3,(THIS_FILE, 
+		  "   Jitter: min=%d.%03dms, avg=%d.%03dms, max=%d.%03dms",
+		  min_jitter/1000, min_jitter%1000, 
+		  avg_jitter/1000, avg_jitter%1000,
+		  max_jitter/1000, max_jitter%1000));
+    } else {
+	test_data->has_error = 1;
+	PJ_LOG(2,(THIS_FILE, 
+		  "   Jitter: min=%d.%03dms, avg=%d.%03dms, max=%d.%03dms",
+		  min_jitter/1000, min_jitter%1000, 
+		  avg_jitter/1000, avg_jitter%1000,
+		  max_jitter/1000, max_jitter%1000));
+    }
+}
+
+
+static int perform_test(const char *title, int dev_id, pjmedia_dir dir,
+		        unsigned clock_rate, unsigned samples_per_frame, 
+			unsigned nchannel, int verbose)
+{
+    pj_status_t status = PJ_SUCCESS;
+    pjmedia_snd_stream *strm;
+    struct test_data test_data;
+
+
+    /*
+     * Init test parameters
+     */
+    pj_memset(&test_data, 0, sizeof(test_data));
+    test_data.dir = dir;
+    test_data.clock_rate = clock_rate;
+    test_data.samples_per_frame = samples_per_frame;
+    test_data.channel_count = nchannel;
+
+    /*
+     * Open device.
+     */
+    PJ_LOG(3,(THIS_FILE, "Testing %s", title));
+
+    if (dir == PJMEDIA_DIR_CAPTURE) {
+	status = pjmedia_snd_open_rec( dev_id, clock_rate, nchannel,
+				       samples_per_frame, 16, &rec_cb, 
+				       &test_data, &strm);
+    } else if (dir == PJMEDIA_DIR_PLAYBACK) {
+	status = pjmedia_snd_open_player( dev_id, clock_rate, nchannel,
+					  samples_per_frame, 16, &play_cb, 
+					  &test_data, &strm);
+    } else {
+	status = pjmedia_snd_open( dev_id, dev_id, clock_rate, nchannel,
+				   samples_per_frame, 16, &rec_cb, &play_cb, 
+				   &test_data, &strm);
+    }
+    
+    if (status != PJ_SUCCESS) {
+        app_perror("Unable to open device for capture", status);
+        return status;
+    }
+
+    /* Sleep for a while to let sound device "settles" */
+    pj_thread_sleep(100);
+
+
+    /*
+     * Start the stream.
+     */
+    status = pjmedia_snd_stream_start(strm);
+    if (status != PJ_SUCCESS) {
+        app_perror("Unable to start capture stream", status);
+        return status;
+    }
+
+    /* Let the stream runs for 1 second to get stable result.
+     * (capture normally begins with frames available simultaneously).
+     */
+    pj_thread_sleep(1000);
+
+
+    /* Begin gather data */
+    test_data.running = 1;
+
+    /* 
+     * Let the test runs for a while.
+     */
+    PJ_LOG(3,(THIS_FILE,
+	      " Please wait while test is in progress (~%d secs)..",
+	      (DURATION/1000)));
+    pj_thread_sleep(DURATION);
+
+
+    /*
+     * Close stream.
+     */
+    test_data.running = 0;
+    pjmedia_snd_stream_close(strm);
+
+
+    /* 
+     * Print results.
+     */
+    PJ_LOG(3,(THIS_FILE, " Dumping results:"));
+
+    PJ_LOG(3,(THIS_FILE, "  Parameters: clock rate=%dHz, %d samples/frame",
+	      clock_rate, samples_per_frame));
+
+    if (dir & PJMEDIA_DIR_PLAYBACK)
+	print_stream_data("Playback", &test_data, &test_data.playback_data, 
+			  verbose);
+    if (dir & PJMEDIA_DIR_CAPTURE)
+	print_stream_data("Capture", &test_data, &test_data.capture_data, 
+			   verbose);
+
+    /* Check drifting */
+    if (dir == PJMEDIA_DIR_CAPTURE_PLAYBACK) {
+	int end_diff, start_diff, drift;
+
+	end_diff = test_data.capture_data.last_timestamp -
+		   test_data.playback_data.last_timestamp;
+	start_diff = test_data.capture_data.first_timestamp-
+		      test_data.playback_data.first_timestamp;
+	drift = end_diff - start_diff;
+
+	PJ_LOG(3,(THIS_FILE, "  Checking for clock drifts:"));
+
+	/* Allow one frame tolerance for clock drift detection */
+	if (drift < (int)samples_per_frame) {
+	    PJ_LOG(3,(THIS_FILE, "   No clock drifts is detected"));
+	} else {
+	    const char *which = (drift<0 ? "slower" : "faster");
+	    unsigned msec_dur;
+
+	    if (drift < 0) drift = -drift;
+
+
+	    msec_dur = (test_data.capture_data.last_timestamp - 
+		       test_data.capture_data.first_timestamp) * 1000 /
+		       test_data.clock_rate;
+
+	    PJ_LOG(2,(THIS_FILE, 
+		      "   Sound capture is %d samples %s than playback "
+		      "at the end of the test (at the rate about %d samples"
+		      " per second)",
+		      drift, which, 
+		      drift * 1000 / msec_dur));
+
+	}
+    }
+
+    if (test_data.has_error == 0) {
+	PJ_LOG(3,(THIS_FILE, " Test completed, sound device looks okay."));
+	return 0;
+    } else {
+	PJ_LOG(2,(THIS_FILE, " Test completed with some warnings"));
+	return 1;
+    }
+}
+
+
+int main(int argc, char *argv[])
+{
+    pj_caching_pool cp;
+    pjmedia_endpt *med_endpt;
+    int id = -1, verbose = 0;
+    int clock_rate = 8000;
+    int frame = -1;
+    int channel = 1;
+    struct pj_getopt_option long_options[] = {
+	{ "id",	     1, 0, 'i' },
+	{ "rate",    1, 0, 'r' },
+	{ "frame",   1, 0, 'f' },
+	{ "channel", 1, 0, 'n' },
+	{ "verbose", 0, 0, 'v' },
+	{ "help",    0, 0, 'h' },
+	{ NULL, 0, 0, 0 }
+    };
+    int c, option_index;
+    
+
+    pj_status_t status;
+
+    /* Init pjlib */
+    status = pj_init();
+    PJ_ASSERT_RETURN(status==PJ_SUCCESS, 1);
+    
+    /* Must create a pool factory before we can allocate any memory. */
+    pj_caching_pool_init(&cp, &pj_pool_factory_default_policy, 0);
+
+    /* 
+     * Initialize media endpoint.
+     * This will implicitly initialize PJMEDIA too.
+     */
+    status = pjmedia_endpt_create(&cp.factory, NULL, 1, &med_endpt);
+    PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
+
+    /* Print devices */
+    enum_devices();
+
+    /* Parse options */
+    pj_optind = 0;
+    while((c=pj_getopt_long(argc,argv, "i:r:f:n:vh", 
+			    long_options, &option_index))!=-1) 
+    {
+	switch (c) {
+	case 'i':
+	    id = atoi(pj_optarg);
+	    break;
+	case 'r':
+	    clock_rate = atoi(pj_optarg);
+	    break;
+	case 'f':
+	    frame = atoi(pj_optarg);
+	    break;
+	case 'n':
+	    channel = atoi(pj_optarg);
+	    break;
+	case 'v':
+	    verbose = 1;
+	    break;
+	case 'h':
+	    puts(desc);
+	    return 0;
+	    break;
+	default:
+	    printf("Error: invalid options %s\n", argv[pj_optind-1]);
+	    puts(desc);
+	    return 1;
+	}
+    }
+
+    if (pj_optind != argc) {
+	printf("Error: invalid options\n");
+	puts(desc);
+	return 1;
+    }
+
+    if (!verbose)
+	pj_log_set_level(3);
+
+    if (frame == -1)
+	frame = 10 * clock_rate / 1000;
+
+
+    status = perform_test(get_dev_name(id), id, PJMEDIA_DIR_CAPTURE_PLAYBACK, 
+			  clock_rate, frame, channel, verbose);
+    if (status != 0)
+	return 1;
+
+    
+    return 0;
+}
+
+