So over the weekend I performed a litle benchmark-test of the conference bridge and am a bit puzzled with the results:
I took the confbench.c code and just commented out the null-ports.
So what happens is it creates sine ports and mixes them in the conference bridge.
I ran the same test with 1,2,4,8,16,32,64,128 and 256 Sineports, one time with resampling and one time without.
My machine is a AMD 64 Dual Core 4600+ with 3gig RAM.
What you see in the attached chart is, that with resampling with only 32 ports the cpu usage is already 100% and without resampling with 250 Sineports the CPU Usage is only 20%.
Does that mean that:
- with resampling you practically can't have conferences with more than 32 people
- without resampling (when you extrapolate) you cant have conferences more than around 1000 people?
What do you think of this conclusion:
If you take decoding, encoding the signal and all the other stuff into account, the limit of Conference-Servers must be somewhere less then 1000 participants in one conference, because they are limited by the computational power and not the available bandwidth?
Can anyone varify this ? Do you have different experiences?
The Code I used to perform the test:
/* $Id: confbench.c 974 2007-02-19 01:13:53Z bennylp $ */
/*
* Copyright (C) 2003-2007 Benny Prijono <
benny <at> 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
*/
/**
* \page page_pjmedia_samples_confbench_c Samples: Benchmarking Conference Bridge
*
* Benchmarking pjmedia (conference bridge+resample). For my use only,
* and it only works in Win32.
*
* This file is pjsip-apps/src/samples/confbench.c
*
* \includelineno confbench.c
*/
#include <pjmedia.h>
#include <pjlib-util.h> /* pj_getopt */
#include <pjlib.h>
#include <stdlib.h> /* atoi() */
#include <stdio.h>
#include <windows.h>
/* For logging purpose. */
#define THIS_FILE "confsample.c"
/* Configurable:
* LARGE_SET will create in total of about 232 ports.
* HAS_RESAMPLE will activate resampling on about half
* the port.
*/
#define TEST_SET LARGE_SET
#define HAS_RESAMPLE 0
#define SMALL_SET 16
#define LARGE_SET 250
#define PORT_COUNT 254
#define CLOCK_RATE 16000
#define SAMPLES_PER_FRAME (CLOCK_RATE/100)
#if HAS_RESAMPLE
# define SINE_CLOCK 32000
#else
# define SINE_CLOCK CLOCK_RATE
#endif
#define SINE_PTIME 20
#define DURATION 10
#define SINE_COUNT TEST_SET
#define NULL_COUNT TEST_SET
#define IDLE_COUNT 32
static void app_perror(const char *sender, const char *title, pj_status_t status)
{
char errmsg[PJ_ERR_MSG_SIZE];
pj_strerror(status, errmsg, sizeof(errmsg));
PJ_LOG(1,(sender, "%s: %s", title, errmsg));
}
struct Times
{
FILETIME kernel_time;
ULARGE_INTEGER u_kernel_time;
FILETIME user_time;
ULARGE_INTEGER u_user_time;
ULARGE_INTEGER u_total;
};
static void process(struct Times *t)
{
pj_memcpy(&t->u_kernel_time, &t->kernel_time, sizeof(FILETIME));
pj_memcpy(&t->u_user_time, &t->user_time, sizeof(FILETIME));
t->u_total.QuadPart = t->u_kernel_time.QuadPart + t->u_user_time.QuadPart;
}
static void benchmark(void)
{
FILETIME creation_time, exit_time;
struct Times start, end;
DWORD ts, te;
LARGE_INTEGER elapsed;
BOOL rc;
int i;
double pct;
puts("Test started!"); fflush(stdout);
ts = GetTickCount();
rc = GetProcessTimes(GetCurrentProcess(), &creation_time, &exit_time,
&start.kernel_time, &start.user_time);
for (i=DURATION; i>0; --i) {
printf("\r%d ", i); fflush(stdout);
pj_thread_sleep(1000);
}
rc = GetProcessTimes(GetCurrentProcess(), &creation_time, &exit_time,
&end.kernel_time, &end.user_time);
te = GetTickCount();
process(&start);
process(&end);
elapsed.QuadPart = end.u_total.QuadPart - start.u_total.QuadPart;
pct = elapsed.QuadPart * 100.0 / ((te-ts)*10000.0);
printf("CPU usage=%6.4f%%\n", pct); fflush(stdout);
}
/* Struct attached to sine generator */
typedef struct
{
pj_int16_t *samples; /* Sine samples. */
} port_data;
/* This callback is called to feed more samples */
static pj_status_t sine_get_frame( pjmedia_port *port,
pjmedia_frame *frame)
{
port_data *sine = port->port_data.pdata;
pj_int16_t *samples = frame->buf;
unsigned i, count, left, right;
/* Get number of samples */
count = frame->size / 2 / port->info.channel_count;
left = 0;
right = 0;
for (i=0; i<count; ++i) {
*samples++ = sine->samples[left];
++left;
if (port->info.channel_count == 2) {
*samples++ = sine->samples[right];
right += 2; /* higher pitch so we can distinguish left and right. */
if (right >= count)
right = 0;
}
}
/* Must set frame->type correctly, otherwise the sound device
* will refuse to play.
*/
frame->type = PJMEDIA_FRAME_TYPE_AUDIO;
return PJ_SUCCESS;
}
#ifndef M_PI
#define M_PI (3.14159265)
#endif
/*
* Create a media port to generate sine wave samples.
*/
static pj_status_t create_sine_port(pj_pool_t *pool,
unsigned sampling_rate,
unsigned channel_count,
pjmedia_port **p_port)
{
pjmedia_port *port;
unsigned i;
unsigned count;
port_data *sine;
PJ_ASSERT_RETURN(pool && channel_count > 0 && channel_count <= 2,
PJ_EINVAL);
port = pj_pool_zalloc(pool, sizeof(pjmedia_port));
PJ_ASSERT_RETURN(port != NULL, PJ_ENOMEM);
/* Fill in port info. */
port->info.bits_per_sample = 16;
port->info.channel_count = channel_count;
port->info.encoding_name = pj_str("pcm");
port->info.has_info = 1;
port->
info.name = pj_str("sine generator");
port->info.need_info = 0;
port->
info.pt = 0xFF;
port->info.clock_rate = sampling_rate;
port->info.samples_per_frame = sampling_rate * SINE_PTIME / 1000 * channel_count;
port->info.bytes_per_frame = port->info.samples_per_frame * 2;
port->info.type = PJMEDIA_TYPE_AUDIO;
/* Set the function to feed frame */
port->get_frame = &sine_get_frame;
/* Create sine port data */
port->port_data.pdata = sine = pj_pool_zalloc(pool, sizeof(port_data));
/* Create samples */
count = port->info.samples_per_frame / channel_count;
sine->samples = pj_pool_alloc(pool, count * sizeof(pj_int16_t));
PJ_ASSERT_RETURN(sine->samples != NULL, PJ_ENOMEM);
/* initialise sinusoidal wavetable */
for( i=0; i<count; i++ )
{
sine->samples[i] = (pj_int16_t) (10000.0 *
sin(((double)i/(double)count) * M_PI * 8.) );
}
*p_port = port;
return PJ_SUCCESS;
}
int main()
{
pj_caching_pool cp;
pjmedia_endpt *med_endpt;
pj_pool_t *pool;
pjmedia_conf *conf;
int i;
pjmedia_port *sine_port[SINE_COUNT], *null_port, *conf_port;
pjmedia_port *nulls[NULL_COUNT];
unsigned null_slots[NULL_COUNT];
pjmedia_master_port *master_port;
pj_status_t status;
pj_log_set_level(3);
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 = pjmedia_endpt_create(&cp.factory, NULL, 1, &med_endpt);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
status = pjmedia_conf_create( pool,
PORT_COUNT,
CLOCK_RATE,
1, SAMPLES_PER_FRAME, 16,
PJMEDIA_CONF_NO_DEVICE,
&conf);
if (status != PJ_SUCCESS) {
app_perror(THIS_FILE, "Unable to create conference bridge", status);
return 1;
}
printf("Resampling is %s\n", (HAS_RESAMPLE?"active":"disabled"));
/* Create sine ports. */
printf("Creating %d sine generator ports..\n", SINE_COUNT);
for (i=0; i<SINE_COUNT; ++i) {
unsigned j, slot;
status = create_sine_port(pool, SINE_CLOCK, 1, &sine_port[i]);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
status = pjmedia_conf_add_port( conf, /* The bridge */
pool, /* pool */
sine_port[i], /* port to connect */
NULL, /* Use port's name */
&slot /* ptr for slot # */
);
if (status != PJ_SUCCESS) {
app_perror(THIS_FILE, "Unable to add conference port", status);
return 1;
}
/* Connect to Sound Device*/
status = pjmedia_conf_connect_port(conf, slot, 0, 0);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
/*
for (j=0; j<NULL_COUNT; ++j) {
status = pjmedia_conf_connect_port(conf, slot, null_slots[j], 0);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
}
*/
}
/* Create idle ports */
/*
printf("Creating %d idle ports..\n", IDLE_COUNT);
for (i=0; i<IDLE_COUNT; ++i) {
pjmedia_port *dummy;
status = pjmedia_null_port_create(pool, CLOCK_RATE, 1, SAMPLES_PER_FRAME, 16, &dummy);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
status = pjmedia_conf_add_port(conf, pool, dummy, NULL, NULL);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
}
*/
/* Create null port */
status = pjmedia_null_port_create(pool, CLOCK_RATE, 1, SAMPLES_PER_FRAME, 16,
&null_port);
PJ_ASSERT_RETURN(status == PJ_SUCCESS, 1);
conf_port = pjmedia_conf_get_master_port(conf);
/* Create master port */
status = pjmedia_master_port_create(pool, null_port, conf_port, 0, &master_port);
pjmedia_master_port_start(master_port);
puts("Waiting to settle.."); fflush(stdout);
pj_thread_sleep(5000);
benchmark();
/* Done. */
return 0;
}
2008/5/28 Benny Prijono <
bennylp <at> pjsip.org>:
On Wed, May 28, 2008 at 2:12 PM, Thomas Plotkowiak <
plotti <at> gmx.net> wrote:
> I will give confbridge a try, should be a good start to gather some data.
> I see there is already resampling possibility in confbench.c, how would I
> add some audiocodecs encoding / decoding to that to get a more realistic
> example?
>
> Cheers,
> Thomas, who is really interested what the outcome of such a test will be ;)
>
Metoo!
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