No microphone input on first run of the android app.

Unity Engine
,
1

Hello, i have a problem.
I’m working on a decibel meter app for android.
So it needs to use the mic of the android device. I did add the uses permission RECORD_AUDIO in the androidmanifest.xml file.
The first (clean) install on my phone, the mic request works, but the microphone is not starting. Now when i exit and start the app again, the microphone works. This is the script i’m using:

using UnityEngine;
using UnityEngine.Android;
using System.Collections;

public class DecibelMeter : MonoBehaviour
{
    private AudioClip recordedClip;
    private AudioSource audioSource;
    private bool isRecording = false;

    IEnumerator Start()
    {
        // Check if a microphone is available
        if (Microphone.devices.Length == 0)
        {
            Debug.LogError("No microphone detected.");
            yield break;
        }

        // Request and check microphone permissions
        RequestMicrophonePermission();
        yield return StartCoroutine(WaitForMicrophonePermission());

        Debug.Log("Microphone access granted.");

        // Add an AudioSource component to this GameObject
        audioSource = gameObject.AddComponent<AudioSource>();

        // Wait for a short delay before proceeding
        yield return new WaitForSeconds(1);

        // Start recording
        StartRecording();
    }

    void RequestMicrophonePermission()
    {
        if (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
        {
            Permission.RequestUserPermission(Permission.Microphone);
        }
    }

    IEnumerator WaitForMicrophonePermission()
    {
        // Wait until the user grants or denies permission
        while (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
        {
            yield return null;
        }
    }

    // Start recording audio (changed to public)
    public void StartRecording()
    {
        if (Microphone.IsRecording(null))
        {
            Debug.LogWarning("Already recording.");
            return;
        }

        int frequency = 44100; // Sample rate
        int seconds = 10; // Maximum recording duration

        recordedClip = Microphone.Start(null, true, seconds, frequency);
        isRecording = true;
    }

    // Stop recording audio
    public void StopRecording()
    {
        if (Microphone.IsRecording(null))
        {
            Microphone.End(null);
            isRecording = false;
        }
        else
        {
            Debug.LogWarning("Not currently recording.");
        }
    }

    // Get the current decibel level and play the recorded audio
    public float GetDecibelLevel()
    {
        if (isRecording && recordedClip != null)
        {
            float[] samples = new float[recordedClip.samples * recordedClip.channels];
            recordedClip.GetData(samples, 0);

            float sum = 0f;

            foreach (float sample in samples)
            {
                sum += Mathf.Abs(sample);
            }

            // Calculate average amplitude
            float averageAmplitude = sum / samples.Length;

            // Convert average amplitude to decibels
            float dbValue = 20 * Mathf.Log10(averageAmplitude + Mathf.Epsilon);  // Add epsilon to prevent log of zero

            // Play the recorded audio if it's not already playing
            if (!audioSource.isPlaying)
            {
                audioSource.clip = recordedClip;
                audioSource.Play();
            }

            return dbValue;
        }

        return 0f; // Return 0 if not recording or no recorded audio
    }
}
class DecibelMeter : MonoBehaviour
{
    private AudioClip recordedClip;
    private AudioSource audioSource;
    private bool isRecording = false;

    IEnumerator Start()
    {
        // Check if a microphone is available
        if (Microphone.devices.Length == 0)
        {
            Debug.LogError("No microphone detected.");
            yield break;
        }

        // Request and check microphone permissions
        RequestMicrophonePermission();
        yield return StartCoroutine(WaitForMicrophonePermission());

        Debug.Log("Microphone access granted.");

        // Add an AudioSource component to this GameObject
        audioSource = gameObject.AddComponent<AudioSource>();

        // Wait for a short delay before proceeding
        yield return new WaitForSeconds(1);

        // Start recording
        StartRecording();
    }

    void RequestMicrophonePermission()
    {
        if (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
        {
            Permission.RequestUserPermission(Permission.Microphone);
        }
    }

    IEnumerator WaitForMicrophonePermission()
    {
        // Wait until the user grants or denies permission
        while (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
        {
            yield return null;
        }
    }

    // Start recording audio (changed to public)
    public void StartRecording()
    {
        if (Microphone.IsRecording(null))
        {
            Debug.LogWarning("Already recording.");
            return;
        }

        int frequency = 44100; // Sample rate
        int seconds = 10; // Maximum recording duration

        recordedClip = Microphone.Start(null, true, seconds, frequency);
        isRecording = true;
    }

    // Stop recording audio
    public void StopRecording()
    {
        if (Microphone.IsRecording(null))
        {
            Microphone.End(null);
            isRecording = false;
        }
        else
        {
            Debug.LogWarning("Not currently recording.");
        }
    }

    // Get the current decibel level and play the recorded audio
    public float GetDecibelLevel()
    {
        if (isRecording && recordedClip != null)
        {
            float[] samples = new float[recordedClip.samples * recordedClip.channels];
            recordedClip.GetData(samples, 0);

            float sum = 0f;

            foreach (float sample in samples)
            {
                sum += Mathf.Abs(sample);
            }

            // Calculate average amplitude
            float averageAmplitude = sum / samples.Length;

            // Convert average amplitude to decibels
            float dbValue = 20 * Mathf.Log10(averageAmplitude + Mathf.Epsilon);  // Add epsilon to prevent log of zero

            // Play the recorded audio if it's not already playing
            if (!audioSource.isPlaying)
            {
                audioSource.clip = recordedClip;
                audioSource.Play();
            }

            return dbValue;
        }

        return 0f; // Return 0 if not recording or no recorded audio
    }
}

Unity 2019.4
Btw. It does work immidiately in unity Editor.
Can someone help me out?
What am i doing wrong?
And yes, i’m a noob.

2

[mmm… déjà vu…]

I’ve experienced this myself but didn’t have much time to get into it… mobile permission stuff can be super tricky.

You could try to stop/start the microphone in StartRecording() by calling Microphone.End(null); before Microphone.Start(...);.

Also, instead of a second corountine polling for when the permission has been granted, your could try using the PermissionCallbacks.

3

Did you ever figure this out? I have the same exact issue right now on Android and can’t find a solution anywhere.

4

No i’m sorry, i stopped working on this project due to this problem, after several months of searching and trying.
For you i hope you find the solution.