Re: Thunderbolt port audio programmability

> On Mar 20, 2020, at 8:00 PM, Carl Hoefs > wrote: > > when the AU subsystem renders this data, it ignores the offset and generates > a "corrected" X-axis-centered audio signal anyway Interesting ... I guess there’s filtering or normalization going on at some stage (in software or in the DAC

Re: Thunderbolt port audio programmability

Thanks for all the helpful insights and links. At this point, I'm using Audio Units in my iOS test app. I can generate signals of specific type, frequency and amplitude. That was the easy part... However, a hard requirement is that the app must generate what amounts to 'DC-offset' signals (full

Re: Thunderbolt port audio programmability

If you want to make more than sine waves, there are a bunch of open source audio libraries/programs for generating arbitrarily fancy waveforms — CSound, Pure Data, Max, Supercollider... These are usually used for music synthesis, but most of them let you do general purpose DSP type stuff. And of

Re: Thunderbolt port audio programmability

I think AVFoundation is probably the easiest way to get started. There’s a pretty good sample on how to do it: https://developer.apple.com/documentation/avfoundation/audio_track_engineering/building_a_signal_generator

Re: Thunderbolt port audio programmability

> On Mar 12, 2020, at 5:31 PM, Carl Hoefs > wrote: > > In iOS, what is the current way to generate precise audio tones? > AVFoundation? CoreAudio? AudioUnits? AudioUnits. It's been a long time since I worked with that API, but I'm pretty sure I recall some sample code showing a generator AU

Re: Thunderbolt port audio programmability

On Thu, 12 Mar 2020 10:27:25 -0700, you wrote: >I'm looking at creating an iPhone/iPad app that acts as a dual-channel >waveform generator. > >I see two options for the output signal medium: > (a) using the audio jack (on suitable devices), or > (b) using the Thunderbolt port As already noted

Re: Thunderbolt port audio programmability

> On Mar 12, 2020, at 11:13 AM, Jens Alfke wrote: > > >> On Mar 12, 2020, at 10:27 AM, Carl Hoefs via Cocoa-dev >> mailto:cocoa-dev@lists.apple.com>> wrote: >> >> I'm looking at creating an iPhone/iPad app that acts as a dual-channel >> waveform generator. >> >> I see two options for the o

Re: Thunderbolt port audio programmability

> On Mar 12, 2020, at 10:27 AM, Carl Hoefs via Cocoa-dev > wrote: > > I'm looking at creating an iPhone/iPad app that acts as a dual-channel > waveform generator. > > I see two options for the output signal medium: > (a) using the audio jack (on suitable devices), or > (b) using the Thund

Thunderbolt port audio programmability

I'm looking at creating an iPhone/iPad app that acts as a dual-channel waveform generator. I see two options for the output signal medium: (a) using the audio jack (on suitable devices), or (b) using the Thunderbolt port Q: Is there a Cocoa framework for programming the Thunderbolt port? Ca