/*
* This program only tracks the difference between system time
* and audio time, as reported in snd_pcm_status(). It should be
* helpful to verify the information reported by drivers.
*/
#include <stdio.h>
#include <malloc.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <time.h>
#include <locale.h>
#include <math.h>
#include "../include/asoundlib.h"
static char *command;
static char *pcm_name = "hw:0";
snd_output_t *output = NULL;
static void usage(char *command)
{
printf("Usage: %s [OPTION]... \n"
"\n"
"-h, --help help\n"
"-c, --capture capture tstamps \n"
"-d, --delay add delay \n"
"-D, --device=NAME select PCM by name \n"
"-p, --playback playback tstamps \n"
"-t, --ts_type=TYPE Default(0),link(1),link_estimated(2),synchronized(3) \n"
"-r, --report show audio timestamp and accuracy validity\n"
, command);
}
long long timestamp2ns(snd_htimestamp_t t)
{
long long nsec;
nsec = t.tv_sec * 1000000000;
nsec += t.tv_nsec;
return nsec;
}
long long timediff(snd_htimestamp_t t1, snd_htimestamp_t t2)
{
long long nsec1, nsec2;
nsec1 = timestamp2ns(t1);
nsec2 = timestamp2ns(t2);
return nsec1 - nsec2;
}
void _gettimestamp(snd_pcm_t *handle, snd_htimestamp_t *timestamp,
snd_htimestamp_t *trigger_timestamp,
snd_htimestamp_t *audio_timestamp,
snd_pcm_audio_tstamp_config_t *audio_tstamp_config,
snd_pcm_audio_tstamp_report_t *audio_tstamp_report,
snd_pcm_uframes_t *avail, snd_pcm_sframes_t *delay)
{
int err;
snd_pcm_status_t *status;
snd_pcm_status_alloca(&status);
snd_pcm_status_set_audio_htstamp_config(status, audio_tstamp_config);
if ((err = snd_pcm_status(handle, status)) < 0) {
printf("Stream status error: %s\n", snd_strerror(err));
exit(0);
}
snd_pcm_status_get_trigger_htstamp(status, trigger_timestamp);
snd_pcm_status_get_htstamp(status, timestamp);
snd_pcm_status_get_audio_htstamp(status, audio_timestamp);
snd_pcm_status_get_audio_htstamp_report(status, audio_tstamp_report);
*avail = snd_pcm_status_get_avail(status);
*delay = snd_pcm_status_get_delay(status);
}
#define TIMESTAMP_FREQ 8 /* Hz */
#define SAMPLE_FREQ 48000
#define PERIOD (SAMPLE_FREQ/TIMESTAMP_FREQ)
#define PCM_LINK /* sync start for playback and capture */
#define TRACK_CAPTURE /* dump capture timing info */
#define TRACK_PLAYBACK /* dump playback timing info */
/*#define TRACK_SAMPLE_COUNTS */ /* show difference between sample counters and audiotimestamps returned by driver */
#define PLAYBACK_BUFFERS 4
#define TSTAMP_TYPE SND_PCM_TSTAMP_TYPE_MONOTONIC_RAW
int main(int argc, char *argv[])
{
int c;
int err;
unsigned int i;
snd_pcm_t *handle_p = NULL;
snd_pcm_t *handle_c = NULL;
snd_pcm_sframes_t frames;
snd_htimestamp_t tstamp_c, tstamp_p;
snd_htimestamp_t trigger_tstamp_c, trigger_tstamp_p;
snd_htimestamp_t audio_tstamp_c, audio_tstamp_p;
unsigned char buffer_p[PERIOD*4*4];
unsigned char buffer_c[PERIOD*4*4];
snd_pcm_hw_params_t *hwparams_p;
snd_pcm_hw_params_t *hwparams_c;
snd_pcm_sw_params_t *swparams_p;
snd_pcm_sw_params_t *swparams_c;
snd_pcm_uframes_t frame_count_c = 0;
snd_pcm_uframes_t frame_count_p = 0;
snd_pcm_sframes_t delay_p, delay_c;
snd_pcm_uframes_t avail_p, avail_c;
snd_pcm_audio_tstamp_config_t audio_tstamp_config_p;
snd_pcm_audio_tstamp_config_t audio_tstamp_config_c;
snd_pcm_audio_tstamp_report_t audio_tstamp_report_p;
snd_pcm_audio_tstamp_report_t audio_tstamp_report_c;
int option_index;
static const char short_options[] = "hcpdrD:t:";
static const struct option long_options[] = {
{"capture", 0, 0, 'c'},
{"delay", 0, 0, 'd'},
{"device", required_argument, 0, 'D'},
{"help", no_argument, 0, 'h'},
{"playback", 0, 0, 'p'},
{"ts_type", required_argument, 0, 't'},
{"report", 0, 0, 'r'},
{0, 0, 0, 0}
};
int do_delay = 0;
int do_playback = 0;
int do_capture = 0;
int type = 0;
int do_report = 0;
while ((c = getopt_long(argc, argv, short_options, long_options, &option_index)) != -1) {
switch (c) {
case 'h':
usage(command);
return 0;
case 'p':
do_playback = 1;
break;
case 'c':
do_capture = 1;
break;
case 'd':
do_delay = 1;
break;
case 'D':
pcm_name = optarg;
break;
case 't':
type = atoi(optarg);
break;
case 'r':
do_report = 1;
}
}
memset(&audio_tstamp_config_p, 0, sizeof(snd_pcm_audio_tstamp_config_t));
memset(&audio_tstamp_config_c, 0, sizeof(snd_pcm_audio_tstamp_config_t));
memset(&audio_tstamp_report_p, 0, sizeof(snd_pcm_audio_tstamp_report_t));
memset(&audio_tstamp_report_c, 0, sizeof(snd_pcm_audio_tstamp_report_t));
if (do_playback) {
if ((err = snd_pcm_open(&handle_p, pcm_name, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
printf("Playback open error: %s\n", snd_strerror(err));
goto _exit;
}
if ((err = snd_pcm_set_params(handle_p,
SND_PCM_FORMAT_S16,
SND_PCM_ACCESS_RW_INTERLEAVED,
2,
SAMPLE_FREQ,
0,
4*1000000/TIMESTAMP_FREQ)) < 0) {
printf("Playback open error: %s\n", snd_strerror(err));
goto _exit;
}
snd_pcm_hw_params_alloca(&hwparams_p);
/* get the current hwparams */
err = snd_pcm_hw_params_current(handle_p, hwparams_p);
if (err < 0) {
printf("Unable to determine current hwparams_p: %s\n", snd_strerror(err));
goto _exit;
}
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 0))
printf("Playback supports audio compat timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 1))
printf("Playback supports audio default timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 2))
printf("Playback supports audio link timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 3))
printf("Playback supports audio link absolute timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 4))
printf("Playback supports audio link estimated timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_p, 5))
printf("Playback supports audio link synchronized timestamps\n");
snd_pcm_sw_params_alloca(&swparams_p);
/* get the current swparams */
err = snd_pcm_sw_params_current(handle_p, swparams_p);
if (err < 0) {
printf("Unable to determine current swparams_p: %s\n", snd_strerror(err));
goto _exit;
}
/* enable tstamp */
err = snd_pcm_sw_params_set_tstamp_mode(handle_p, swparams_p, SND_PCM_TSTAMP_ENABLE);
if (err < 0) {
printf("Unable to set tstamp mode : %s\n", snd_strerror(err));
goto _exit;
}
err = snd_pcm_sw_params_set_tstamp_type(handle_p, swparams_p, TSTAMP_TYPE);
if (err < 0) {
printf("Unable to set tstamp type : %s\n", snd_strerror(err));
goto _exit;
}
/* write the sw parameters */
err = snd_pcm_sw_params(handle_p, swparams_p);
if (err < 0) {
printf("Unable to set swparams_p : %s\n", snd_strerror(err));
goto _exit;
}
}
if (do_capture) {
if ((err = snd_pcm_open(&handle_c, pcm_name, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK)) < 0) {
printf("Capture open error: %s\n", snd_strerror(err));
goto _exit;
}
if ((err = snd_pcm_set_params(handle_c,
SND_PCM_FORMAT_S16,
SND_PCM_ACCESS_RW_INTERLEAVED,
2,
SAMPLE_FREQ,
0,
4*1000000/TIMESTAMP_FREQ)) < 0) {
printf("Capture open error: %s\n", snd_strerror(err));
goto _exit;
}
snd_pcm_hw_params_alloca(&hwparams_c);
/* get the current hwparams */
err = snd_pcm_hw_params_current(handle_c, hwparams_c);
if (err < 0) {
printf("Unable to determine current hwparams_c: %s\n", snd_strerror(err));
goto _exit;
}
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 0))
printf("Capture supports audio compat timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 1))
printf("Capture supports audio default timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 2))
printf("Capture supports audio link timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 3))
printf("Capture supports audio link absolute timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 4))
printf("Capture supports audio link estimated timestamps\n");
if (snd_pcm_hw_params_supports_audio_ts_type(hwparams_c, 5))
printf("Capture supports audio link synchronized timestamps\n");
snd_pcm_sw_params_alloca(&swparams_c);
/* get the current swparams */
err = snd_pcm_sw_params_current(handle_c, swparams_c);
if (err < 0) {
printf("Unable to determine current swparams_c: %s\n", snd_strerror(err));
goto _exit;
}
/* enable tstamp */
err = snd_pcm_sw_params_set_tstamp_mode(handle_c, swparams_c, SND_PCM_TSTAMP_ENABLE);
if (err < 0) {
printf("Unable to set tstamp mode : %s\n", snd_strerror(err));
goto _exit;
}
err = snd_pcm_sw_params_set_tstamp_type(handle_c, swparams_c, TSTAMP_TYPE);
if (err < 0) {
printf("Unable to set tstamp type : %s\n", snd_strerror(err));
goto _exit;
}
/* write the sw parameters */
err = snd_pcm_sw_params(handle_c, swparams_c);
if (err < 0) {
printf("Unable to set swparams_c : %s\n", snd_strerror(err));
goto _exit;
}
}
if (do_playback && do_capture) {
#ifdef PCM_LINK
if ((err = snd_pcm_link(handle_c, handle_p)) < 0) {
printf("Streams link error: %s\n", snd_strerror(err));
exit(0);
}
#endif
}
if (do_playback) {
i = PLAYBACK_BUFFERS;
while (i--) {
frames = snd_pcm_writei(handle_p, buffer_p, PERIOD);
if (frames < 0) {
printf("snd_pcm_writei failed: %s\n", snd_strerror(frames));
goto _exit;
}
frame_count_p += frames;
}
if (PLAYBACK_BUFFERS != 4)
snd_pcm_start(handle_p);
}
if (do_capture) {
#ifndef PCM_LINK
/* need to start capture explicitly */
snd_pcm_start(handle_c);
#else
if (!do_playback)
/* need to start capture explicitly */
snd_pcm_start(handle_c);
#endif
}
while (1) {
if (do_capture) {
frames = snd_pcm_wait(handle_c, -1);
if (frames < 0) {
printf("snd_pcm_wait failed: %s\n", snd_strerror(frames));
goto _exit;
}
frames = snd_pcm_readi(handle_c, buffer_c, PERIOD);
if (frames < 0) {
printf("snd_pcm_readi failed: %s\n", snd_strerror(frames));
goto _exit;
}
frame_count_c += frames;
#if defined(TRACK_CAPTURE)
audio_tstamp_config_c.type_requested = type;
audio_tstamp_config_c.report_delay = do_delay;
_gettimestamp(handle_c, &tstamp_c, &trigger_tstamp_c,
&audio_tstamp_c, &audio_tstamp_config_c, &audio_tstamp_report_c,
&avail_c, &delay_c);
#if defined(TRACK_SAMPLE_COUNTS)
curr_count_c = frame_count_c + delay_c; /* read plus queued */
printf("capture: curr_count %lli driver count %lli, delta %lli\n",
(long long)curr_count_c * 1000000000LL / SAMPLE_FREQ ,
timestamp2ns(audio_tstamp_c),
(long long)curr_count_c * 1000000000LL / SAMPLE_FREQ - timestamp2ns(audio_tstamp_c)
);
#endif
if (do_report) {
if (audio_tstamp_report_c.valid == 0)
printf("Audio capture timestamp report invalid - ");
if (audio_tstamp_report_c.accuracy_report == 0)
printf("Audio capture timestamp accuracy report invalid");
printf("\n");
}
printf("\t capture: systime: %lli nsec, audio time %lli nsec, \tsystime delta %lli \t resolution %d ns \n",
timediff(tstamp_c, trigger_tstamp_c),
timestamp2ns(audio_tstamp_c),
timediff(tstamp_c, trigger_tstamp_c) - timestamp2ns(audio_tstamp_c), audio_tstamp_report_c.accuracy
);
#endif
}
if (do_playback) {
frames = snd_pcm_writei(handle_p, buffer_p, PERIOD);
if (frames < 0) {
printf("snd_pcm_writei failed: %s\n", snd_strerror(frames));
goto _exit;
}
frame_count_p += frames;
#if defined(TRACK_PLAYBACK)
audio_tstamp_config_p.type_requested = type;
audio_tstamp_config_p.report_delay = do_delay;
_gettimestamp(handle_p, &tstamp_p, &trigger_tstamp_p,
&audio_tstamp_p, &audio_tstamp_config_p, &audio_tstamp_report_p,
&avail_p, &delay_p);
#if defined(TRACK_SAMPLE_COUNTS)
curr_count_p = frame_count_p - delay_p; /* written minus queued */
printf("playback: curr_count %lli driver count %lli, delta %lli\n",
(long long)curr_count_p * 1000000000LL / SAMPLE_FREQ ,
timestamp2ns(audio_tstamp_p),
(long long)curr_count_p * 1000000000LL / SAMPLE_FREQ - timestamp2ns(audio_tstamp_p)
);
#endif
if (do_report) {
if (audio_tstamp_report_p.valid == 0)
printf("Audio playback timestamp report invalid - ");
if (audio_tstamp_report_p.accuracy_report == 0)
printf("Audio playback timestamp accuracy report invalid");
printf("\n");
}
printf("playback: systime: %lli nsec, audio time %lli nsec, \tsystime delta %lli resolution %d ns\n",
timediff(tstamp_p, trigger_tstamp_p),
timestamp2ns(audio_tstamp_p),
timediff(tstamp_p, trigger_tstamp_p) - timestamp2ns(audio_tstamp_p), audio_tstamp_report_p.accuracy
);
#endif
}
} /* while(1) */
_exit:
if (handle_p)
snd_pcm_close(handle_p);
if (handle_c)
snd_pcm_close(handle_c);
return 0;
}