At Fri, 21 Sep 2012 20:05:18 -0500, Pierre-Louis Bossart wrote:
Simple test to create playback and capture streams, and check elapsed time vs. sample counts reported by driver. This should be helpful for driver developers and anyone interested in system/audio time drift.
tested only on HDAudio
TODO:
- make period configurable
- better output messages
- support for wall clock when it's in the mainline
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Applied now. Thanks.
Takashi
test/audio_time.c | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 test/audio_time.c
diff --git a/test/audio_time.c b/test/audio_time.c new file mode 100644 index 0000000..a910783 --- /dev/null +++ b/test/audio_time.c @@ -0,0 +1,237 @@ +/*
- 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_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);
- *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 PLAYBACK_BUFFERS 4
+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;
- unsigned char buffer_p[PERIOD*4*4];
- unsigned char buffer_c[PERIOD*4*4];
- 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_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;- }
- /* 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_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;- }
- /* 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, &avail_p, &delay_p);curr_count_p = frame_count_p - delay_p; /* written minus queued */printf("playback: systime: %lli nsec, sample time %lli nsec \tsystime delta %lli \n",timediff(tstamp_p,trigger_tstamp_p),(long long)round(((float)curr_count_p * 1000000000.0 / 48000.0)),timediff(tstamp_p, trigger_tstamp_p) - (long long)round((double)curr_count_p * 1000000000.0 / 48000.0));+#endif
+#if defined(TRACK_CAPTURE)
gettimestamp(handle_c, &tstamp_c, &trigger_tstamp_c, &avail_c, &delay_c);curr_count_c = frame_count_c + delay_c; /* read plus queued */printf("\t capture: systime: %lli nsec, sample time %lli nsec \tsystime delta %lli \n",timediff(tstamp_c,trigger_tstamp_c),(long long)round(((float)curr_count_c * 1000000000.0 / 48000.0)),timediff(tstamp_c, trigger_tstamp_c) - (long long)round((double)curr_count_c * 1000000000.0 / 48000.0));+#endif
}+_exit:
- if (handle_p)
snd_pcm_close(handle_p);- if (handle_c)
snd_pcm_close(handle_c);- return 0;
+}
1.7.9.5
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