Multi-channel files on IOS

We have an IOS app that wants to use a multichannel file.

We don’t need more than 2 output channels, but we do need to be able to use a multichannel source.

We use an AudioFormatReaderSource to open a multichannel wav file and put it into an AudioTransportSource.

The ComponentS GetNextAudioBlock is always supplied an AudioSourceChannelInfo with a buffer that has a scope of 2 channels. We can pick-up the AudioTransportSource’s GetNextAudioBlock and that does have the n channels expected, but sometimes, it has a different sample block size (this is something to do with BT headphones, but haven’t worked it out yet)

How can we increase the channel scope of the AudioSourceChannelInfo to be the same size as the scope of the AudioFormatReaderSource ?

I was going to necro this post iOS Audio: can't access input channel 3 or higher - #10 by Ronney_Guimaraes to ask if anything ever changed?