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/* $Id$ */
/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 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
*/
/* See http://trac.pjsip.org/repos/wiki/MeasuringSoundLatency on
* how to use this program.
*/
#include <pjmedia.h>
#include <pjlib.h>
#include <stdio.h>
#define THIS_FILE "lacency.c"
/* Util to display the error message for the specified error code */
static int app_perror( const char *sender, const char *title,
pj_status_t status)
{
char errmsg[PJ_ERR_MSG_SIZE];
PJ_UNUSED_ARG(sender);
pj_strerror(status, errmsg, sizeof(errmsg));
printf("%s: %s [code=%d]\n", title, errmsg, status);
return 1;
}
/*
* Find out latency
*/
static int calculate_latency(pj_pool_t *pool, pjmedia_port *wav)
{
pjmedia_frame frm;
short *buf;
unsigned i, samples_per_frame, read, len;
unsigned start_pos;
pj_status_t status;
unsigned lat_sum = 0,
lat_cnt = 0,
lat_min = 10000,
lat_max = 0;
samples_per_frame = PJMEDIA_PIA_SPF(&wav->info);
frm.buf = pj_pool_alloc(pool, samples_per_frame * 2);
frm.size = samples_per_frame * 2;
len = pjmedia_wav_player_get_len(wav);
buf = pj_pool_alloc(pool, len + samples_per_frame);
read = 0;
while (read < len/2) {
status = pjmedia_port_get_frame(wav, &frm);
if (status != PJ_SUCCESS)
break;
pjmedia_copy_samples(buf+read, (short*)frm.buf, samples_per_frame);
read += samples_per_frame;
}
if (read < 2 * PJMEDIA_PIA_SRATE(&wav->info)) {
puts("Error: too short");
return -1;
}
start_pos = 0;
while (start_pos < len/2 - PJMEDIA_PIA_SRATE(&wav->info)) {
int max_signal = 0;
unsigned max_signal_pos = start_pos;
unsigned max_echo_pos = 0;
unsigned pos;
unsigned lat;
/* Get the largest signal in the next 0.7s */
for (i=start_pos; i<start_pos + PJMEDIA_PIA_SRATE(&wav->info) * 700 / 1000; ++i) {
if (abs(buf[i]) > max_signal) {
max_signal = abs(buf[i]);
max_signal_pos = i;
}
}
/* Advance 10ms from max_signal_pos */
pos = max_signal_pos + 10 * PJMEDIA_PIA_SRATE(&wav->info) / 1000;
/* Get the largest signal in the next 500ms */
max_signal = 0;
max_echo_pos = pos;
for (i=pos; i<pos+PJMEDIA_PIA_SRATE(&wav->info)/2; ++i) {
if (abs(buf[i]) > max_signal) {
max_signal = abs(buf[i]);
max_echo_pos = i;
}
}
lat = (max_echo_pos - max_signal_pos) * 1000 / PJMEDIA_PIA_SRATE(&wav->info);
#if 0
printf("Latency = %u\n", lat);
#endif
lat_sum += lat;
lat_cnt++;
if (lat < lat_min)
lat_min = lat;
if (lat > lat_max)
lat_max = lat;
/* Advance next loop */
start_pos += PJMEDIA_PIA_SRATE(&wav->info);
}
printf("Latency average = %u\n", lat_sum / lat_cnt);
printf("Latency minimum = %u\n", lat_min);
printf("Latency maximum = %u\n", lat_max);
printf("Number of data = %u\n", lat_cnt);
return 0;
}
/*
* main()
*/
int main(int argc, char *argv[])
{
enum { NSAMPLES = 160, COUNT=100 };
pj_caching_pool cp;
pj_pool_t *pool;
pjmedia_port *wav;
pj_status_t status;
/* Verify cmd line arguments. */
if (argc != 2) {
puts("Error: missing argument(s)");
puts("Usage: latency REV.WAV");
return 1;
}
pj_log_set_level(0);
status = pj_init();
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
pj_caching_pool_init(&cp, &pj_pool_factory_default_policy, 0);
pool = pj_pool_create( &cp.factory, /* pool factory */
"wav", /* pool name. */
4000, /* init size */
4000, /* increment size */
NULL /* callback on error */
);
status = pj_register_strerror(PJMEDIA_ERRNO_START, PJ_ERRNO_SPACE_SIZE,
&pjmedia_strerror);
pj_assert(status == PJ_SUCCESS);
/* Wav */
status = pjmedia_wav_player_port_create( pool, /* memory pool */
argv[1], /* file to play */
0, /* use default ptime*/
0, /* flags */
0, /* default buffer */
&wav /* returned port */
);
if (status != PJ_SUCCESS) {
app_perror(THIS_FILE, argv[1], status);
return 1;
}
status = calculate_latency(pool, wav);
if (status != PJ_SUCCESS)
return 1;
status = pjmedia_port_destroy( wav );
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
pj_pool_release( pool );
pj_caching_pool_destroy( &cp );
pj_shutdown();
/* Done. */
return 0;
}
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