[LAD] Midi Beat Clock to BPM

[Robin Gareus]

On 11/01/2014 08:10 PM, Clemens Ladisch wrote:
> hermann meyer wrote:
>> I try to fetch the bpm from the Midi Clock, and stumble over "jitter".
>>
>> How do you usually fetch the bpm from Midi Clock, any pointer will be welcome.
> 
> <http://en.wikipedia.org/wiki/Phase-locked_loop>
> <http://en.wikipedia.org/wiki/Kalman_filter>
> 
> MIDI clock is interesting, because deviations from the predicted clock
> frequency are either errors and must be suppressed, or are because of
> a change in tempo and must replace the old clock rate.
> 

A very good paper with example code:
 http://kokkinizita.linuxaudio.org/papers/usingdll.pdf
(ardour uses that approach to filter MTC, LTC and MClk)

ciao,
robin