Ignoring the given bitrate on ios

[rootux]

for the following code -

Stream<Uint8List>? stream = await MicStream.microphone(
    sampleRate: 16000,
    channelConfig: ChannelConfig.CHANNEL_IN_MONO,
    audioFormat:AudioFormat.ENCODING_PCM_16BIT
);

final sampleRate = await MicStream.sampleRate;
final bitDepth = await MicStream.bitDepth;
final bufferSize = await MicStream.bufferSize;
logger.i(
  'Microphone settings: sampleRate = $sampleRate, bitDepth = $bitDepth, bufferSize = $bufferSize',
);

I get back this -

flutter: Microphone settings: sampleRate = 48000.0, bitDepth = 16, bufferSize = 1024

Hence the library is ignoring the settings. I know @anarchuser you did not write that part :) Trying to figure out a solution

[anarchuser]

Yeah, I remember there were issues regarding iOS settings/sample rate. You can try out some of the older versions, I think the recording API used in the iOS backend changed in-between

[rootux]

There is this comment in the code that may be related - https://github.com/anarchuser/mic_stream/blob/main/ios/Classes/SwiftMicStreamPlugin.swift#L148

// neither does setting AVLinearPCMBitDepthKey on audioOutput.audioSettings (unavailable on iOS)
// 99% sure it's not possible to set streaming sample rate/bitrate
// try AVAudioSession.sharedInstance().setPreferredOutputNumberOfChannels(numChannels)

[rootux]

@anarchuser Not sure what do you mean. Can you please elaborate?

I see some change in the area here - https://github.com/anarchuser/mic_stream/pull/61/files#diff-92b5a8c491b845cd6d9e20f37fe82c7d10f0410693426936cb7515f4dd23007eR118

[anarchuser]

It will take me some time to look into it. If you want please give it a look yourself. I think it shouldn't be difficult; I just cannot test it myself.

[DurandA]

On iOS, setPreferredSampleRate() is used and there is no guarantee that it will be applied. In fact, it is ignored on most devices and the actual sampling rate is device dependent.

If you require a specific sampling rate for your application, you have to resample the audio.