High Latency When Starting Recording in record Plugin on iPhone 11 (iOS 18)

[Djsmk123]

Package version
5.2.1

Environment

• iOS 18 in Iphone 11 and simulator iOS 18

Description:

I am experiencing a high latency when starting audio recording using the record plugin on an iPhone 11 running iOS 18. The delay between initiating the recording and the actual start time is around 1 second, which is significantly high for real-time applications.

Steps to Reproduce:

Stopwatch stopwatch = Stopwatch()..start();
// Record to file
await recordFile(_audioRecorder, config);
stopwatch.stop();
print("Time taken: ${stopwatch.elapsed}");

Observed Output:

flutter: [
  id: Built-In Microphone
  label: iPhone Microphone
]
flutter: Time taken: 0:00:01.065523

Expected Behavior:

The recording should start with minimal delay (<30ms), as it happing in my current application where it took 1-3 seconds to start first time and from next time it took less than 50 ms.

[llfbandit]

This should be mostly due to audio session initialization but since you don't provide anything helpful, I can't go further...
Also, you output a listing of available microphones, so time taken could be anything in hidden recordFile method.
Finally, don't assume anything in debug mode, only profile and release modes are relevant for such issues.

[langyuxiansheng]

I also encountered this problem, the preparation time for recording was too long, and the user experience was not very friendly.

[langyuxiansheng]

This method takes about 1-3 seconds to complete during startup, which is a poor user experience. I hope it can be optimized and addressed.

[tyukesz]

Setup sessions before you start recording.

I had the same problem, but it turns out, it takes a lot until audio session is setup, therefore disable audio session management by this package and do it with Audio Session package only once, before using the recorder. I did the audio session setup in main.

const recorderConfig = RecordConfig(
          sampleRate: 16000,
          encoder: AudioEncoder.wav,
          bitRate: 16000,
          iosConfig: IosRecordConfig(
            manageAudioSession: false, // <------ this is config you need
          ),
      );