Jaroslav Kysela kirjoitti: > On Mon, 26 Nov 2007, Heikki Lindholm wrote: > >> Hello, >> >> Some years ago there was some talk about UST support in Linux, but the >> support never happened. With the hrtimers patch (and I'm not quite sure >> if even earlier?) CLOCK_MONOTONIC would seem like a fairly good UST time >> source. What I'd like to see, is a selectable clock for ALSA >> timestamping, e.g. something like snd_sw_params_clock(..., clockid_t >> clk). Would this seem plausible? I don't know that much about ALSA >> internals, so, no idea whether different clocks on different >> pcms/whatever would quickly turn into an unmanageable mess. > > We are aware about this extension and I already proposed an > implementation. I hope to implement it soon. Timestamps are not used in > driver internally. I had a look at the proposal and the thread at http://thread.gmane.org/gmane.linux.alsa.devel/45237/focus=45573 I don't know about the history of SNDRV_PCM_IOCTL_TSTAMP, but since it currently seems unused I don't see a problem reusing it for something (else). However, I think that it'd be nicer to define the API to use a POSIX clock id instead of some arbitrary constants, because there have been/are other clocks on Linux, for example, CLOCK_SGI_CYCLE. An update to pcm_status might also be in order to tell which clock is being used. -- Heikki Lindholm _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
