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2 commits

Author SHA1 Message Date
Pierre-Louis Bossart
cf40ea169a pcm: support for audio timestamps
add new snd_pcm_status_get_audio_htstamp() routine to
query the audio timestamps provided by the kernel.

This change provides applications with better ways
to track elapsed time. Before this patch, applications
would subtract queued samples (delay) from written samples,
resulting in a 1-2 sample error.

Also add snd_pcm_hw_params_supports_audio_wallclock_ts()
to query what the hardware supports.

TODO: check protocol compatibility?

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-10-25 00:13:51 +02:00
Pierre-Louis Bossart
6429a450a3 test: add audio_time
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

[added Makefile.am change by tiwai]

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-09-22 09:39:07 +02:00