mirror of
https://github.com/alsa-project/alsa-lib.git
synced 2025-11-03 09:01:52 -05:00
298 lines
8.7 KiB
C
298 lines
8.7 KiB
C
/*
|
|
* 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 "../include/asoundlib.h"
|
|
#include <math.h>
|
|
|
|
static char *device = "hw:0,0";
|
|
|
|
snd_output_t *output = NULL;
|
|
|
|
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_uframes_t *avail, snd_pcm_sframes_t *delay)
|
|
{
|
|
int err;
|
|
snd_pcm_status_t *status;
|
|
|
|
snd_pcm_status_alloca(&status);
|
|
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);
|
|
*avail = snd_pcm_status_get_avail(status);
|
|
*delay = snd_pcm_status_get_delay(status);
|
|
}
|
|
|
|
#define PERIOD 6000
|
|
#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
|
|
|
|
|
|
int main(void)
|
|
{
|
|
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 curr_count_c;
|
|
snd_pcm_uframes_t frame_count_c = 0;
|
|
snd_pcm_uframes_t curr_count_p;
|
|
snd_pcm_uframes_t frame_count_p = 0;
|
|
|
|
snd_pcm_sframes_t delay_p, delay_c;
|
|
snd_pcm_uframes_t avail_p, avail_c;
|
|
|
|
if ((err = snd_pcm_open(&handle_p, device, 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,
|
|
48000,
|
|
0,
|
|
500000)) < 0) { /* 0.5sec */
|
|
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_wallclock_ts(hwparams_p))
|
|
printf("Playback relies on audio wallclock timestamps\n");
|
|
else
|
|
printf("Playback relies on audio sample counter 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 ((err = snd_pcm_open(&handle_c, device, 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,
|
|
48000,
|
|
0,
|
|
500000)) < 0) { /* 0.5sec */
|
|
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_wallclock_ts(hwparams_c))
|
|
printf("Capture relies on audio wallclock timestamps\n");
|
|
else
|
|
printf("Capture relies on audio sample counter 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;
|
|
}
|
|
|
|
#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
|
|
|
|
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);
|
|
|
|
#ifndef PCM_LINK
|
|
/* need to start capture explicitly */
|
|
snd_pcm_start(handle_c);
|
|
#endif
|
|
|
|
while (1) {
|
|
|
|
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;
|
|
|
|
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)
|
|
gettimestamp(handle_p, &tstamp_p, &trigger_tstamp_p, &audio_tstamp_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 / 48000 ,
|
|
timestamp2ns(audio_tstamp_p),
|
|
(long long)curr_count_p * 1000000000LL / 48000 - timestamp2ns(audio_tstamp_p)
|
|
);
|
|
#endif
|
|
|
|
printf("playback: systime: %lli nsec, audio time %lli nsec, \tsystime delta %lli\n",
|
|
timediff(tstamp_p, trigger_tstamp_p),
|
|
timestamp2ns(audio_tstamp_p),
|
|
timediff(tstamp_p, trigger_tstamp_p) - timestamp2ns(audio_tstamp_p)
|
|
);
|
|
#endif
|
|
|
|
#if defined(TRACK_CAPTURE)
|
|
gettimestamp(handle_c, &tstamp_c, &trigger_tstamp_c, &audio_tstamp_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 / 48000 ,
|
|
timestamp2ns(audio_tstamp_c),
|
|
(long long)curr_count_c * 1000000000LL / 48000 - timestamp2ns(audio_tstamp_c)
|
|
);
|
|
#endif
|
|
|
|
printf("\t capture: systime: %lli nsec, audio time %lli nsec, \tsystime delta %lli\n",
|
|
timediff(tstamp_c, trigger_tstamp_c),
|
|
timestamp2ns(audio_tstamp_c),
|
|
timediff(tstamp_c, trigger_tstamp_c) - timestamp2ns(audio_tstamp_c)
|
|
);
|
|
#endif
|
|
|
|
}
|
|
|
|
_exit:
|
|
if (handle_p)
|
|
snd_pcm_close(handle_p);
|
|
if (handle_c)
|
|
snd_pcm_close(handle_c);
|
|
|
|
return 0;
|
|
}
|