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What is the difference between samplerate, subaudio, and capyrate?

+2 votes

I noticed that TimeIndex has a dropping slope, where OscillatorTimeIndex drops within 1 sample. So I wonder what exactly is the difference between audio and subaoudio modules and outputs. Is subaudio downrated to save dsp? In what ratio?
Also wondering about capyrate: is it synced to samplerate? so if I use a 1Khz freq oscillator, will all capyrate events occur at beginning of the oscillator’s cycles?

asked Feb 3, 2016 in Capytalk & Smalltalk by malcolm-braff (Practitioner) (770 points)

1 Answer

+5 votes
The designations "audio" and "sub-audio" do not pertain to the update rate but only to whether they are changing at a rate that lies within the range of human hearing.  In other words, the LFO, the AR envelope and other modules may be sub-audio but they are still computed at the sample rate, just as the audio modules are.

Capytalk expressions in the parameter fields are evaluated (between sample ticks) whenever a value they depend on changes, irrespective of the millisecond clock.  Capytalk expressions that are functions of time are evaluated once per millisecond.

If you have a Sound pasted into a parameter field as part of a Capytalk expression, the Sound is evaluated at the sample rate, but its value is read only when the expression of which it is a part is evaluated once per millisecond.

If a Sound is pasted into certain parameter fields (the ones with a biege background) and the Sound is in the field on its own (no Capytalk expression or 'L' after the Sound), then it is both computed and updated at the sample rate.

In answer to your question, a 1 kHz frequency Oscillator would line up with the millisecond clock if you sample rate is an integer multiple of 1000 (for example, 48 kHz would work but 44.1 kHz would not line up).
answered Feb 7, 2016 by ssc (Savant) (127,080 points)