Turning on SpeakerPhone does not work in Android API >= 31 when

audio mode is IN_COMMUNICATION

app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt

@@ -41,7 +41,6 @@ import java.util.*
 import kotlin.collections.ArrayList
 import kotlin.concurrent.schedule
 import kotlin.math.roundToInt
-import kotlin.system.exitProcess
 
 class BaresipService: Service() {
 
@@ -880,7 +879,7 @@ class BaresipService: Service() {
                             call.remove()
                             if (Call.calls().size == 0) {
                                 resetCallVolume()
-                                am.isSpeakerphoneOn = false
+                                Utils.setSpeakerPhone(am, false)
                                 am.stopBluetoothSco()
                                 abandonAudioFocus()
                                 am.mode = AudioManager.MODE_NORMAL

app/src/main/kotlin/com/tutpro/baresip/MainActivity.kt

@@ -1144,8 +1144,12 @@ class MainActivity : AppCompatActivity() {
                     if (acc.missedCalls)
                         callsButton.setImageResource(R.drawable.calls_missed)
                 }
-                if (speakerIcon != null)
+                if (speakerIcon != null) {
-                    speakerIcon!!.setIcon(R.drawable.speaker_off)
+                    if (am.isSpeakerphoneOn)
+                        speakerIcon!!.setIcon(R.drawable.speaker_on)
+                    else
+                        speakerIcon!!.setIcon(R.drawable.speaker_off)
+                }
                 if ((Build.VERSION.SDK_INT >= 22 && kgm.isDeviceLocked) ||
                         (Build.VERSION.SDK_INT < 22 && kgm.isKeyguardLocked && kgm.isKeyguardSecure))
                     Utils.setShowWhenLocked(this, false)
@@ -1230,7 +1234,7 @@ class MainActivity : AppCompatActivity() {
             }
 
             R.id.speakerIcon -> {
-                am.isSpeakerphoneOn = !am.isSpeakerphoneOn
+                Utils.setSpeakerPhone(am, !am.isSpeakerphoneOn)
                 if (am.isSpeakerphoneOn)
                     item.setIcon(R.drawable.speaker_on)
                 else

app/src/main/kotlin/com/tutpro/baresip/Utils.kt

@@ -25,6 +25,8 @@ import android.view.View
 import android.view.WindowManager
 import android.widget.ImageView
 import android.widget.TextView
+import android.media.AudioDeviceInfo
+import android.media.AudioManager
 import androidx.activity.result.ActivityResultLauncher
 import androidx.annotation.RequiresApi
 import androidx.core.content.ContextCompat
@@ -890,4 +892,32 @@ object Utils {
         return bitmap
     }
 
+    fun setSpeakerPhone(am: AudioManager, state: Boolean) {
+        // Currently at API levels 31+, speakerphone cannot be turned on during call
+        Log.d(TAG, "Speakerphone is ${am.isSpeakerphoneOn}")
+        if (state) {
+            if (Build.VERSION.SDK_INT >= 31 && am.mode != AudioManager.MODE_IN_COMMUNICATION) {
+                var speakerDevice: AudioDeviceInfo? = null
+                for (device in am.availableCommunicationDevices)
+                    if (device.type == AudioDeviceInfo.TYPE_BUILTIN_SPEAKER) {
+                        speakerDevice = device
+                        break
+                    }
+                if (speakerDevice != null) {
+                    if (!am.setCommunicationDevice(speakerDevice))
+                        Log.e(TAG, "Could not turn on speaker device")
+                }
+            } else {
+                if (Build.VERSION.SDK_INT < 31)
+                    am.isSpeakerphoneOn = true
+            }
+        } else {
+            if (Build.VERSION.SDK_INT >= 31)
+                am.clearCommunicationDevice()
+            else
+                am.isSpeakerphoneOn = false
+        }
+        Log.d(TAG, "Speakerphone is ${am.isSpeakerphoneOn}")
+    }
+
 }