iOS 14 - blocksize (was: samplerate) issues with AirPods Pro


when I’m running the audio application I’m developing on iOS 14.0.1 (or, iPadOS to be precise) with a pair of AirPods Pro (latest firmware), I’m running into samplerate issues. Here’s what’s happening:

  • When I first start the App, THEN connect the AirPods, everything works fine
  • When the AirPods are already connected, then the App is started and I start playback, it plays back four times as fast.

The strange thing, the samplerate retrieved from the device manager (WITH the AirPods connected) and that of the file match.

Re-initialising or restarting the device doesn’t help …

Any hints why this is happening?

EDIT: maybe I should clarify, playback is not only four times as fast, but also distorted in a downsample-y way.

Also, I’m using AudioFormatReaderSource and AudioTransportSource

After doing some research, it seems that the blocksize is the culprit … the AudioDeviceManager reports 256 when calling getAudioDeviceSetup(), but it’s actually just 64 … the AudioDeviceManager.tempBuffer has the correct size though … not sure if this is a JUCE bug or apple bug ?