[alsa-devel] [PATCH v2 3/3] snd_pcm_start_at: Implement snd_pcm_start_at for system and audio tstamp types.

[Raymond Yau]

>
> System tstamp types rely on high-res timers.
> Audio tstamp types delegate to the pcm driver.
> Current start_at timer is cancelled on attempt to change stream state.

http://git.alsa-project.org/?p=alsa-lib.git;a=blob_plain;f=test/timer.c;hb=HEAD

Are there any difference between sound card's timer with high res
timer/wall clock time stamp ?

It seem those sound cards timer have resolution and max tick

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/ymfpci?id=6e2efaacb3579fd9643d0dc59963b58b801c03a1

snd_timer_status_get_resolution

The clock tick counters are 32 bits and wrap around

This may mean that snd_pcm_start_at can only start within certian time
interval