search

grame-cncm / faust

Functional programming language for signal processing and sound synthesis
http://faust.grame.fr
Other
2.58k stars 322 forks source link

faust2api -ios: How to build an app not asking for microphone access? #457

Closed oshibka404 closed 4 years ago

oshibka404 commented 4 years ago

The iOS application I am creating using faust2api is a synthesizer not currently using audio inputs at all.

By default, when launched for the first time, the application asks the user to provide it with Microphone access.

It still works fine no matter you allow or disallow, however it affects the overall first launch experience anyway.

I'm wondering if there is a way to build the C++ API in a way that wouldn't require microphone access?

Thanks in advance.

oshibka404 commented 4 years ago

According to the faust2firefox-generated block diagram, my Faust code doesn't have any inputs. So as far as I can tell, it shouldn't call methods accessing the device's microphone.

oshibka404 commented 4 years ago

According to the launch logs, audioCategory is set as kAudioSessionCategory_MediaPlayback and hardware input channels count is 0

2020-06-29 19:01:32.165687+0200 Runner[2135:119121] Metal API Validation Enabled
SetParameters fDevNumInChans = 0 fDevNumOutChans = 2 bufferSize = 256 samplerate = 44100
AudioCategory kAudioSessionCategory_MediaPlayback
Get hw input channels 0
Get hw output channels 1
Get hw sample rate 44100.000000
Get hw buffer duration 0.023220
preferredPeriodDuration 0.005805 
preferredPeriodDuration 0.005805 actualPeriodDuration 0.005805
inputLatency in sec : 0.000000
outputLatency in sec : 0.012766
Get kAudioUnitProperty_MaximumFramesPerSlice 1156
- - - - - - - - - - - - - - - - - - - -
  Sample Rate:0.000000
  Format ID:mcpl
  Format Flags:29
  Bytes per Packet:4
  Frames per Packet:1
  Bytes per Frame:4
  Channels per Frame:2
  Bits per Channel:32
- - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - -
  Sample Rate:0.000000
  Format ID:mcpl
  Format Flags:29
  Bytes per Packet:4
  Frames per Packet:1
  Bytes per Frame:4
  Channels per Frame:2
  Bits per Channel:32
- - - - - - - - - - - - - - - - - - - -

But the app still requests the microphone access on the first launch.

sletz commented 4 years ago

The low-level code is there if you want to debug: https://github.com/grame-cncm/faust/blob/master-dev/architecture/faust/audio/coreaudio-ios-dsp.h

sletz commented 4 years ago

kAudioSessionCategory_MediaPlayback is supposed to be used with output only programs. So I don't really know why the system asks for permission. (see https://github.com/grame-cncm/faust/blob/master-dev/architecture/faust/audio/coreaudio-ios-dsp.h#L235)

oshibka404 commented 4 years ago

closed by mistake, sorry for the noise