Re: [LAD] Fw: Re: Deriving a steady MIDI clock crossplatform?
On Thu, May 19, 2022 at 11:17:28PM +0200, Jeanette C. wrote: > Thanks both of you. Based on timed_wait, I looked at the boost libraries and > found two candidates in the Thread library: > conditional_varaible::timed_wait > and > thread::sleep_until > which can both take an absolute time. I suppose both should be equally > usable, since again absolute time can be calculated independent of the last > wait/sleep? Better check how this is implemented. It could just use usleep(). And then all precision is lost, even if the sleep times are adjusted to compensate for the latency of the previous event. Ciao, -- FA ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Fw: Re: Deriving a steady MIDI clock crossplatform?
Thanks both of you. Based on timed_wait, I looked at the boost libraries and found two candidates in the Thread library: conditional_varaible::timed_wait and thread::sleep_until which can both take an absolute time. I suppose both should be equally usable, since again absolute time can be calculated independent of the last wait/sleep? Best wishes, Jeanette May 19 2022, Fons Adriaensen has written: On Thu, May 19, 2022 at 10:40:48PM +0200, Robin Gareus wrote: While there is a corresponding mach/clock.h, for the case at hand it is preferable to use Apple's Core Audio, CoreMIDI. MIDI Event scheduling is abstracted, and there is dedicated API to convert timestamped events with high precision: AudioConvertNanosToHostTime() and AudioConvertHostTimeToNanos() The problem here is not conversion, but what to wait for, In zita-convolver.h there is an implementation of sem_t for OSX (which only has a crippled implementation), using a condition variable. It doesn't have sem_timedwait(), (since zita-convolver doesn't need it) but that could be added quite easily. Ciao, -- FA ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-dev -- * Website: http://juliencoder.de - for summer is a state of sound * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g * Audiobombs: https://www.audiobombs.com/users/jeanette_c * GitHub: https://github.com/jeanette-c If there's nothing missing in my life Then why do these tears come at night <3 (Britney Spears) ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Fw: Re: Deriving a steady MIDI clock crossplatform?
On Thu, May 19, 2022 at 10:40:48PM +0200, Robin Gareus wrote: > While there is a corresponding mach/clock.h, for the case at hand it is > preferable to use Apple's Core Audio, CoreMIDI. MIDI Event scheduling is > abstracted, and there is dedicated API to convert timestamped events > with high precision: > > AudioConvertNanosToHostTime() and AudioConvertHostTimeToNanos() The problem here is not conversion, but what to wait for, In zita-convolver.h there is an implementation of sem_t for OSX (which only has a crippled implementation), using a condition variable. It doesn't have sem_timedwait(), (since zita-convolver doesn't need it) but that could be added quite easily. Ciao, -- FA ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Fw: Re: Deriving a steady MIDI clock crossplatform?
On 5/19/22 22:27, Fons Adriaensen wrote: > Don't know about Apple. Last time I looked it didn't have clock_gettime(), While there is a corresponding mach/clock.h, for the case at hand it is preferable to use Apple's Core Audio, CoreMIDI. MIDI Event scheduling is abstracted, and there is dedicated API to convert timestamped events with high precision: AudioConvertNanosToHostTime() and AudioConvertHostTimeToNanos() -- robin OpenPGP_signature Description: OpenPGP digital signature ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/linux-audio-dev
