[Csnd] Mac: real-time sample rate
| Date | 2019-03-07 03:22 |
| From | Michael Mossey |
| Subject | [Csnd] Mac: real-time sample rate |
I'd like some help knowing what's going on with the real-time sample rate on a Mac. I have a DAC which reports the current sample rate of it's S/PDIF input, which I'm driving from a MIDI -> S/PDIF convertor that works with MacOS natively (no driver needed). The sample rate reported by my DAC seems to be stuck sometimes. Some software changes it, but other software doesn't. For instance, Reaper will change the sample rate to match the Reaper project rate, but VLC won't change it, even if it's playing video encoded at a different rate. Csound doesn't change the DAC's sample rate. If I put SR=96000 in my orc with flags to write real-time audio, the DAC won't change to 96K. It will stay at 44.1 or 192 or wherever Reaper last left it. Any idea what's going on? Mike |
| Date | 2019-03-07 09:13 |
| From | Anders Genell |
| Subject | Re: [Csnd] Mac: real-time sample rate |
I really am the wrong person to supply any kind of answer, but I just wanted to clarify: what is a MIDI->S/PDIF converter? MIDI is control signal at a few khz, audio is much higher resolution, generally, like you mention i.e. 88.2 or 192. How dows the conversion work?
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Regards, Anders |
| Date | 2019-03-07 09:28 |
| From | Michael Mossey |
| Subject | Re: [Csnd] Mac: real-time sample rate |
Oops, I meant USB -> S/PDIF On Thu, Mar 7, 2019 at 1:13 AM Anders Genell <anders.genell@gmail.com> wrote:
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| Date | 2019-03-07 09:38 |
| From | Anders Genell |
| Subject | Re: [Csnd] Mac: real-time sample rate |
Ah, yes, that does make a bit more sense :-) I don't know how it is on a mac, but in general there can be layers of audio data handling between a certain software and an audio hardware. One or more of these layers may offer audio resampling, so that the audio stream is adapted to the setting of the hardware. In other cases the software has fewer layer to pass before reaching the hardware, and may in such case ask the hardware to set a certain sampling frequency. Maybe reaper uses a audio backend that allows control of the hardware. I suppose you might try to try different audio backends for Csound. From the reference manual concerning command line flags: "-+rtaudio=string (max. length = 20 characters) Real time audio module name. The default is PortAudio (all platforms). Also available, depending on platform and build options: Linux: alsa, jack; Windows: mme; Mac OS X: CoreAudio. In addition, null can be used on all platforms, to disable the use of any real time audio plugin." Regards, Anders On Thu, Mar 7, 2019 at 10:29 AM Michael Mossey <michaelmossey@gmail.com> wrote:
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