[LAD] SMPTE and jackd

Robin Gareus robin at gareus.org
Tue May 8 15:31:46 UTC 2012

On 05/08/2012 05:24 PM, Fons Adriaensen wrote:
> On Tue, May 08, 2012 at 03:50:44PM +0200, Robin Gareus wrote:
>> @Paul, Fons,..: does it use a PLL or simply return the difference from
>> clock_gettime() since the beginning of the cycle?
> jack_frame_time() reads the current time from Jack's usecs timer,
> subtracts the cycle start time estimated by the PLL, converts the
> difference to frames, and adds the frame count at the start of the
> current cycle (which is jack_last_frame_time()).
>> IIRC Fons reworked some of jack timing functions not too long ago when
>> writing zita-a2j, zita-j2a, but don't know if they also affect the
>> transport API.
> The changes do not modify any part of the API, they add to it.
> Ciao,

thanks for this explanation.

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