I found some links for understanding callback scenario in realtime audio. https://ccrma.stanford.edu/software/stk/crealtime.html http://portaudio.com/docs/v19-doxydocs/blocking_read_write.html http://www.rossbencina.com/code/real-time-audio-programming-101-time-waits-for-nothing
cheers, akntk On Sun, Feb 22, 2015 at 2:36 AM, Jonghyun Kim <[email protected]> wrote: > Thanks David for your answer. > > I understand what mean audio buffer and block size. Now I'm on Linux with > Jack backend, and the block size controlled by jack. I know how to change > the block size with [block~] or [switch~] in sub-patch. > > But I still don't understand the difference between Callback scenario and > Block method. I think that I don't know what is Callback in audio settings. > I searched about that, but I couldn't see good answer for me. > > Thanks in advance, > akntk > > > > On Wed, Feb 18, 2015 at 11:26 AM, David Medine <[email protected]> wrote: > >> Basically these things have to do with performance. >> >> 'Use callbacks' has to do with how Pd communicates with your soundcard. >> There are two options, using callbacks, and blocking. In the callbacks >> scenario, your computer processes samples then asks the sound card to 'call >> you back' when it's ready to receive those samples (i.e. when it is out of >> audio to play and needs some more). In the meantime, you can process more >> samples, or check out what's going on on CNN.com or whatever. >> >> In the blocking method the computer hands the samples to the soundcard by >> calling a function and if the sound card is not ready, it 'blocks' meaning >> it stops your function in its tracks until it is ready to receive the data. >> Your thread (Pd) will halt until the function that sends the audio has >> finished. >> >> Anybody out there, please correct me if I am spreading misinformation >> here, but this is my understanding of this distinction. >> >> Delay(msec) is a delay between logical time (when your computer computes >> the audio) and real time (when the sound comes out the speaker). You want >> to have some head room here. I've seen really good setups get down to below >> 10ms (as low as 4) without any glitches, but usually you want much more >> time ~50ms or so. >> >> >> On 2/17/2015 5:42 PM, Jonghyun Kim wrote: >> >> Fyi, I use jack on Linux for PD. >> On Feb 18, 2015 8:16 AM, "Jonghyun Kim" <[email protected]> wrote: >> >>> Hi list, >>> >>> I would like to know about some features in audio settings. >>> >>> I don't understand what mean these options. >>> >>> *Delay(msec)* and *Use callbacks* >>> >>> I googled these options, but still I don't understand. Is there some >>> document about it? >>> >>> Thanks in advance, >>> akntk >>> >> >> >> _______________________________________________pd-l...@lists.iem.at mailing >> list >> UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> >> >> >> _______________________________________________ >> [email protected] mailing list >> UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> >> >
_______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
